This irritates me because I met Jack in Montréal last year and I talked about karting and how being 90kg made me too slow but obviously now I realize I'm just terrible. The worst part is the experiment was done with the guy I discussed this with...
Montreal my favorite place to visit Have done some indoor karting there. As for weight not many could beat my 130 pounds. Run Briggs Master at Mosport and minimum driver weight is 200 lbs My seat looks like Swiss Cheese and carry 5 lbs of soft weight in each pocket.
@@genedrakes686 Same. I whey around 132-134 lbs and when I went Karting with my 176 lbs dad on a relatively fast outdoor circuit in France it didn't really seem to hinder him much (even though he said so :D ). I mostly gained time compared to him while accelerating onto the straits and in the breaking zones. Not so much in the infield which consisted mostly of medium speed corners.
And me it irritates that they just took their best lap. It's obvious that they'll be making better and better laps, not to mention being inconsistant and dropping an amazing lap once a while. They should've cut out something like top 25% and bottom 50% of times and take average of the rest of the laps... You spend a lot of time making this experiment and then you fuck up with the data analysis like that.
I'd typically agree with Jacks guess that 20kg would add 0.6 seconds. Usually I've seen that 10kg adds roughly 3 tenths. There are so many other variables though so it makes it hard to measure with complete accuracy.
On my track, which was 800m and done in 43 seconds with the beginner karts(a bit slower than club100, but way faster than rentals) we said it was 0.1s/kg/lap. The class was 100kg min. driver+kart. It's both different from class to class and track to track though. With a heavier kart that has more horses one extra kilo will mean way less though. These rentals often weigh around 100-120kg on their own.
I work at a kart track with laptimes around 1.08, and after alot of testing we concluded that 10kg is around 5 tenths. It also depends on how much you start with 60 to 70kg makes more difference than 80 to 90kg. So i guess the type of track is also important.
@@Chilukar yeah but thats the thing, we tested with lead sheets at the bottom of the seat, wich should be ideal, yet it still was 0.05 sec/kg. However we have an asphalt track wich has way more grip, so my guess is the advantage of better midcorner grip with more weight doesnt apply that much
@@TheEvanovitch Yeah but as Jack said in the video, that would lower the centre of gravity. Most people with 20-30kg extra weight will often be taller so the extra weight would be combined with a higher centre of gravity and make the kart less stable. At least, thats my excuse and I'm sticking to it 😜
Note to self for making a move: Hire a hobo to run with a camera and a gyroscope and pretend I'm a professional cinematographer. At least your average viewer will find it beautiful.
I know these karts are available to the public and a bit different in terms of handling. But I worked at Ocala Grand Prix as a race mechanic for a little while . Working with the Tony Karts and Rotax. And you’d be so surprised how much weight makes a difference in the pro karts. For example the smaller drivers generally had a advantage as they could place lead weight in different areas of the kart to get better stability in the front or rear. And generally 1 pound can equal 1 tenth a lap . Which is massive . However with the public karts it’s different. It’s really luck of the draw on who gets the best kart. Especially when we switched our old public karts that were 4 strokes to the new rotax 2 stroke karts. It was essentially who had the best carb haha. Interesting to see this test though non the less !! Great content as always ! Keep it up guys !!
This karting series has been brilliant, I’m just back from Dubai and last year my best time around their outdoor track was a 1:17:3, this year its a 1:15:7 and the tips from this series helped a lot because I know I can still get that time down even more
Ca. 2 Zehntel pro 10 Kg auf ner 30 Sekunden (flachen) Indoorstrecke sind auch meine Erfahrung. Bei 9ps Indoor sieht das nach Strecke schon wieder ein wenig anders aus, zumindest trennt sich da dann eher die Spreu vom Weizen zwischen den Fahrern die nur gewichtsbereinigt schnell sind und denjenigen die wirklich fahren können.
I'm very surprised to see this. The track I go to actually have a weight equalization system, and I've used it a couple of times to compare my laptimes with different weights, and I've concluded that weight has a huge impact on laptimes.
@@raensaeck But it's a litteral weight system, where you add weights to the karts, made to equal out the weight, so everyone weighs the same when driving.
@@Brobak And how does it handle the different weight distribution? That could be a big factor, and it has also been mentioned that depending on the track it can have a lot of difference between the effects.
Being lighter allows later braking and earlier on the throttle on exit which beats that bit of extra grip. Also, the sluggish start puts you back in the gird. A few kgs does not really make much of a difference but being a natural 110kg I am slower than I was at 90kg in a race.
extra grip from mass can never offset the extra load on the tires from said mass. cornering is still worse with more weight. that's why downforce is good, it's "weight without the mass".
Had a driver 105 pounds heavier than me make me look slow in the corners . Then got my spot back on the straights and back and forth we went ! He helped lift my club kart one day He knew it was heavy but not THAT heavy! To me his kart light as a feather!
Great series, great video! Obviously there are many more "outside influences" that will change your pace, but it was still nice to see an example of how weight can affect your times. That affect will be different from Kart to Kart and from track to track, but it's still a good indicator. What I feel is also a downside in karting is being tall, but you can't really recreate that. Being tall gives you more drag first of all and second of all you can't adjust your position in the kart to help your driving style. You're basically forced to sit as far back as you can to have room for your legs. That weight distribution can affect the times quite a bit as well I think. I would be intersted in you trying out different positions with the seat of the kart and see how much it changes your times, because the position can change the kart from understeer to oversteer really quick. But overall thank you for the great content with this series!
If you're tall you sit further back for good rear-end grip but can lean forwards it times you need more front end grip. If you're short (like me), you have less control over weight distribution. Being tall gives advantages.
Im 5.5 and in every kart I use i have to put the seat as close as I can to the steering. this leads to have all the weight on the front of the kart and sliding everywhere. I lose around 1-2 second a lap just for this issue.
I regularly race @ Teamsport (Harlow) and there is a group of around 10 of us that vary in weight and age (55-80 kg/14-50) and we are all with 0.4 of a second of each other week in week out. The main issue with their tracks is: once you know the line its very difficult to overtake. Still great fun though, the leaderboard is very competetive but it does put off the newer racers. We often see people turn up for a race, get annihilated and then never come back. It took us months and a lot of £££ to get up the leaderboard. Good vids, would love to see you visit some other tracks (or at least Harlow!).
@@cleanycloth Yup. Very grippy, physical track compared to the other Teamsport tracks I've raced. You should come to Track Attack on the 30th (4 x 20 min races). One of the best events they do.
Mate if I lived neqr harlow I would straight up head down to the track right now and blast you all off the leaderboard within 10laps and I'm sorry but that's just a fact.
Regardless of weight differences all things being equal otherwise, if you're only running 0.10 seconds off of Jack's best lap, I doubt you're losing many races to your buds. Solid driving from both of you guys.
Friction Force scales linearly with the normal weight ie more weight = more friction between the tyres and surface. The losses are really only due to acceleration and braking. My mate is 10kg heavier than me and regularly puts down better laps; he is just a better racer. It only really matters on the grand scale of larger circuits with lots of acceleration and deceleration
@@ItsThatMilkshake Well you get more grip with more weight, but not linearly more grip. The tire graph for grip over downforce is not linear, but degressive. So you actually will not be able to get around corners as well as with less weight, because the added grip through the downforce will not make up for the added lateral acceleration force (F = m*a). Same applies for acceleration and braking. The added momentum through extra weight will have a greater effect than the added "friction". So the losses are not only due to acceleration and breaking, but also due to less maximum velocity in the corners before the tires lose grip. Granted, the effects in hobby karting wont be too big.
Really depends on the track. I also tried it with 10 kilo's extra on a track without elevation change. I was 3 thenths slower. And I have 6 years of rental kart experience so im not a complete fool.
Max van Laar 6 years of just rental isn’t much, you probably haven’t learned the level of adaptability needed yet - the track where I work shows pretty much the same kinda stuff as this video does
Did 3 solid years of indoor . Then in a 7 year span did 10 seasons at 2 different tracks for Arrive + Drive with a added 3.5 seasons as a track marshall for A+D and club races. My last 3 years was as a kart owner for Briggs Masters. For indoor time did alright against various drivers from total idiots to pro racers . For the outdoor A+D I rarely missed the podium as I was the lightest driver. Being a kart owner a whole different story! Day 1 with no weight was 2nd fastest by .068 . After adding 65 pounds being in top 10 was like a win. As for being my own mechanic I really suck! The very last race I did with my kart made sure I qualified last and pulled all the weight off for the final. The kart felt so much better !! At the end of the day if a good time was had and a repair bill of zero then all is good! Plus was a washed up never was when found out what I was "good at " Most ready to retire at 35!!
it may be also difference in humidity of air and track temperature... at certain threshold values the public go-kart venue can go like +-1s within couple of hours (only few venues do change so massively, but consistently over years I was racing/practising there) (my experience comes from over a decade of indoor amateur karting, doing races over most of the venues in Czech rep. and states around) So doing one more run without weight right after the weighted run or at least showing how much apart those runs were would be nice. But from my experience (being now 93kg with helmet, and when we are racing at venues with option to add weights, we add up to base weight 85kg, so I'm still +8kg to others), I lose massively more time from me being bad driver, than from the weight. Although in some venues with longer straights, in race, the exits from corners are a bit depressing, when you are at same speed going out and at certain point their kart goes just a bit faster and gets 1kart length advantage... But before blaming your weight for results, unless you are pro-driver level, there's probably another 1-2s to gain just in "your hands"... :D
@WTF1 We did this at our local E-karting track here in the states. We set tire pressures, alignments and had one of our fastest drivers compete against myself and the results of him at 120 vs me at 150 was split by a 23.5 and my own 23.7. Once we added weights just like these I ended up running a 23.7 and he ran a 23.8. Our top guys are all very consistent and the battles are close. We are talking about adding weights to the U.S.A. E-karting championship to balast the weights and also have weight classes since it does make a slight difference, and that slight difference at the top of competition makes a significant difference. Glad you guys covered this!!
Hugs. At least you're a guy. It does not help your mental when your peers are half your weight and they are the standard in life and not just in karting🙆🏾♀️🤣
@@seth6526 I'm fairly hefty at 6ft/95-98kg (also big boned) and I barely squeezed into a F1 2008 replica cockpit, there was no seat so I could get my hips in but my shoulders were uncomfortably pinched and once in I was wedged and couldn't get back out
@@DjDolHaus86 I'm just a weird shape in general. I'm not fat (as in flabby with rolls 😂) but have chunky legs, a wide pelvis and shoulders and a long body and 6ft 1 so I'd have no chance 😂
8:40 it doesn't keep you more planted, there is more force going into the ground but there is also more force pointing outward from the direction you're turning, countering any benefit you could have from the extra mass.
Depends on whether you use the 4 strokes or 2 stroke karts too, 4 strokes are like turbo diesels with good low down torque and don't rev high, 2 stroke karts require more skill to drive where you have to keep the revs up to keep in the power. 4 strokes are better if you are heavy but in the end the lighter driver will always have an advantage with a faster kart
About 4-strokes. If straights are connected with hairpin turns, yes you will lose more. If they are connected with longer, rounder turns, you might gain time instead of losing it. No idea about 2 strokes, never driven one of those.
Ok but 2 years ago my weight was 100kg now im 72kg and at my local go kart (on asphalt outdoor karting) my time is 1 seconde quicker and I’m really constant when I’m driving so I think it’s dépend of the track, surface and kart spec maybe
Woefully unscientific. Do a drag run over a certain distance with one kart, and then add 20 kg to that kart and time it over the same distance interval, it will be slower. This would actually be a great test in rental karts because there's no manually operated clutch and they aren't powerful enough for wheelspin, so you'd just floor it and go. This is true in any vehicle, look at all of the cars, motorcycles, etc. that have the same engine with the same tune and the heavier one is always proportionately slower. F=ma, it's physics guys. On a track like this, how you drive it, how warmed up the kart and tires are, etc. matter a great deal. Also the kart setup matters as having weight in certain areas can fix over or understeer, and tire pressures will favor lighter or heavier drivers as well as a tire with too much pressure may have a smaller contact patch with a lighter driver, but might buckle and hop with too heavy of a driver on a lower pressure tire. On a cold track with a cold kart, a driver 100 lbs lighter than me might not run faster than my typical lap time, but then once the track and tires are at ideal temps (which takes lots of people running the track for at least about 30 minutes on rental karts), I will no doubt beat his cold time, but he will have run even faster in the warm conditions all else being the same in ideal conditions. I've seen times vary as much 2-3 seconds on a ~35 second-per-lap indoor kart track between first session on a cold track and a warm session at the end of the day with consistent drivers that can lap within a tenth of a second every lap. If you're 5 seconds off it's your driving (or a dud kart), but on equal karts a 20kg lighter driver is going to run 0.5-1 second faster depending on track length and complexity, I've observed this at literally every league race I've ever been to that had different weight classes. And don't tell me "oh, it's because the light drivers are just better", not only are the heavier guys usually older with many years of racing school, track days, and even wheel to wheel racing under their belt (compared to many light drivers who are teenagers and haven't done any of that and barely have a basic driver's license), but when the track does a special configuration that nobody has seen before just for a league night, the heavy guys are usually faster at first because the light drivers don't have the real skills and knowledge, and only after they've put in a ton of laps (or followed a heavy driver to learn the line) do they start running faster. This video is nonsense. To reiterate and conclude: weight matters. More than a second on most tracks is likely the fault of a driver, but a substantial weight difference will matter all else being equal and the 2 tenths shown here probably has more to do with warming up the kart/track before running the heavier lap. Gather all of the fastest laps for the year in each weight group and you will ALWAYS see a gap between weight segments unless there simply aren't any good drivers in one of the segments.
But you're oversimplifying things. Engines perform best at certain loads and have certain limits on accelerations unrelated to mass. Tires are also highly non linear and respond differently to various loads, temperatures, conditions and more complex interactions. While this video is quite unscientific it's more about showing that there's still a lot you can do to improve before you blame it purely on weight
Best post and good arguments mate:) also adding extra weight so low in a kart lowers the COG(center of gravity), thats why it feels more planted. This test was rubbish.
When it comes to lap times, usually the difference is minor, but when it comes to acceleration and braking for overtaking and defending, that's when weight may be a problem.
the way they added the extra mass has a way lower center of gravity than the weight of just being a larger person (as in both taller and/or fatter). to be 100% fair they should have added 10kg on the seat and wore a 10kg weighted vest.
Not to mention larger riders typically have to move their seat back, which further disturbs the center of mass and moves the weight closer to the rear. @@GraveUypo
i weigh 100 kilos and when go karting with me friend that weighs 70 our lap times were two tenths away from each other i was slower so we decided to do a standing start together and we found that in the corners i kept up with him but on the straights i lost a lot of time both same hire karts.
Cheers, I don't have to feel too bad about being 57kg now! Was nice to see how weight affects the flow & style of driving, been to teamsport docklands once with a friend who's something like twice my weight, best times were 49.7 vs 51.4. I did put this down to the weight difference & more so the lack of power because we've always been quite closely matched otherwise in cars & sim racing (where he's quicker a lot of the time). We would likely be closer with two strokes on a quicker track, IIRC there wasn't such a large difference when driving the more powerful club karts at another outdoor venue.
Weight doesn‘t impact your cornering. If your weight increases by 20% your grip increases by 20%. But also the centrifugal Force increases by 20%. It evens out. The only thing you will have is slower acceleration. Braking is the same. Again, 20% more grip while breaking, but also 20% more force pushing you forward. Evens out. I‘m shocked a f2 driver doesn‘t know this. Its one of the first things you learn in mechanics. Edit: Not entirely true, look into the Comments for more information. I didn‘t took tire load sensitivity into account. Thanks for correcting me.
Totally wrong. The coefficient of friction is reduced with increased vertical load (weight or downforce). That is called the tire load sensitivity and it is the fundamental principle behind car dynamics (and the reason why anti roll bars and suspension stiffness matter). Engineering explained did a nice overview of this: ua-cam.com/video/kNa2gZNqmT8/v-deo.html.
@@ASJC27 Not only does the load decrease the coefficient of friction, but it also is more mass that needs to change direction. I'm baffled by these people thinking weight doesn't matter, go drive an empty car and then one with a car full of lead and tell me which is faster and corners better, even if you beef up the suspension to compensate for the extra static load.
ASJC27 So i‘ve looked at the video, very interesting indeed. I didn‘t know the fact that the coefficient of friction decreases with load. I always got told the correlation is linear (we didn‘t talk about vehicle dynamics). But, he says in his video that the coefficient of friction is fairly stable up to a specific point where it drops off. In his example he doubles the weight of the vehicle. So we don‘t know how the tires of the cart behave with 20 kg added weight.
Formula Ultralight With a changing coefficient of friction, yes, of course cornering is going to be worse. I admit I didn‘t know that. But i‘d like you to explain to me why weight does matter, if you assume the coefficient of friction is constant. Because if you set up the equations assuming that the coefficient of friction is constant, the mass cuts out and isn‘t in the equation anymore.
Baring from tire overheating, weight doesn't affect cornering speed. You get extra grip from the extra weight, but you also need the same extra grip to pull the same lateral g force. The same goes for braking. Weight doesn't affect your performance when mechanical grip is the limiting factor (cornering, braking, and accelerating out of corners where you can't give full throttle). It gets more complicated when you consider weight transfer but that's negligible on a rigid-frame go kart.
As a rule of thumb, for traction limited racecars, 10kg adds 1/10th of a second every 750 metres. So, for a 3km track, if you somehow find a way to make the car/driver combination 10kg lighter, you should see a 0.4s improvement in lap time, all other things being equal. Likewise, 10kg of success ballast should slow a car/driver down by 0.4s/lap. In indoor karting, funny things can occur. 10kg is a lot of extra weight for a 9hp engine, but it's also a fair amount of weight with regard to the total weight. More weight pressing down on the tyres also equals more grip. This track is quite slick, so if there were places where Jack couldn't quite carry the speed he wanted, that situation could be improved, allowing him to negate the hit in accelleration he'll undoubtedly take. Let's watch the video and see what transpired on the day.
Worth mentioning what I have noticed. On some slippery tracks with not to much accelaration needed out of corners -> more open corners I have noticed that you can be to light weight -> les grip in corners. I was for a long time wondering why my brother 85 kg could go trought that open long corner so much faster without sliping like me with 68 kg After some research and talking with the track ceeper he stated that he noticed that every track has an somewhat ideal weight, I added 10 kg and have improved my times on that track, because I now can take that long open corner way faster without slipping.
Pretty much as expected. The difference is smaller in rental carting than real racing due to the hard hockey puck tyres. The increased weight get them up to higher temps(with some increased grip) , which ofsets the extra weight quite a bit.
*Hello I have a very serious&personal question: Im really tall. About 203 centimeters. (And bit more than 90kg) I feel like being tall also really affect your laptime. Because you have to put your seat and pedals really far from the steering wheel, so you have a worse weight balance in turns (I mean "I lost the rear" more than my friends who are smaller). Also being tall, you have much more of your body parts "outside" of the kart, I also feel like it is affecting your weight balance (and maybe your aerodynamic..?)* *So being tall and by the way being heavier adds a lot of tenths at your laptime, isn't it? So how to compare yourself to your friends?!!* Really big issue here. I hope someone could say if some of the things I said are true or false. Thanks. Great video!
Hey man. Obviously not Matt or relate to WTF1, but if you haven't look up former F1 driver Alex Wurz. The Austrian recently had a very nice beyond the grid podcast episode and he talks specifically about this, he isn't as tall as you, but he's still too tall for the usual standard of F1 driver size, which as a particular problem he talks about when he had to go into a 2005 McLaren for a race and the car was not at all made for a man of his frame. Not to spoil it, but basically he had to compensate his size/weight disadvantage (which there is, mostly due to weight as his size was accomodated as long as the designer considered him when designing the car)by working harder at the engineering/setup side. Mark Webber is also a "tall" F1 driver who took his talent as far as it could, but in some seasons he looked unhealthily thin.
@@zeroelus yeah ok. Now you reminded me an interview of JE Vergne where he was also talking about his tall issue. When he was in Toro Rosso he had to put a less "thick" seat to not have his helmet right on the air intake above his head. So he said that he had sometimes backpain due to his driving position.. Sad
You got normaly(depends on chassi) better weight balance in turns, how strange that sounds..... gokart shall run on three wheels in turns... You get more aerodynamic losses.
I can assure skill is > weight I went sitting for the first time ever today and was the lightest on the track by at least 50lbs+ and was still getting lapped until I figured out the track and speed and breaking and all that.
8:40 You might be more planted (stable over the bumps) but that’s not downforce. Any increase on cornering friction is offset (and a then a bit) by the increased inertia refusing to be cornered. Downforce gives you the cornering friction without the added inertia. If you have downforce adding weight reduces the effectiveness of your downforce because the downforce is making up less of a percentage of the pressure on the tire. F1 downforce would be unnoticeable on a bus but on a light F1 car it’s very noticeable. In a similar way adding mass to a light car will reduce its power to weight ratio more than adding mass to an already heavy car (see the results of this video). The weight being lower will help with stability.
there may still be a bias as when you have been timing the benchmark, you usually improve the more you drive. you could have warmed up the karts and got used to the kart before starting the test, so it would be a fair test
Jack Hughes if you’ve got experience with these A+D karts you’ll know that warming up only helps to a point besides experienced karters don’t improve much (it’s clear these guys have been before / had many practice laps)
Henry Walter I race semi professionally mate, if you’re always quicker in the last stint that means you as a driver are still improving whereas someone like jack wouldn’t be still improving
My guess is that there are a couple of different factors at play some an an advantage some disadvantage. For example at turn in the extra weight will give more grip against the extra inertia. Which is more affected probably depending on the steering angle. Then there is the polar moment of inertia which affects how quickly the kart pivots around its centre and how responsive it is, how stable or twitchy it is. Then there is the centrifugal force once into the bend versus extra grip afforded by the weight. I believe centrifugal is exponential with regard to speed whereas weight is linear. Each factor will vary in significance at different parts of the track.
The weight is added very low, and seat is not moved. Normally if you weigh 20-30 kgs more than your competitor, you're also 4-8 inches taller - and your seat shifted all the way back. I bet the impact had been bigger, if seat was shifted back a bit, and weight added to shoulders.
Still feels wrong. Not sure about this analysis. Also, where to place extra weight does affect balance through corners. Extra weight does affect time to top speed as well as beating inertia. Shouldn't weight interfere, there'd be no need for drivers to weigh in before and after races. Do it again, only now make it outdoors with long straights.
I’ve done a fair bit of kart racing at club level and my theory about carrying weight on ones body is that upper body size is the biggest factor as opposed to overall weight. This in my opinion defo slows you down as this weight is less centralised and thus means there are more cornering forces on your upper body and also to a lesser extent a greater upper body mass means more drag. This test didn’t rally factor any of this in, but agree that we all have used extra weight as an excuse for our shite driving skills, myself included 😂
I totally agree. A few years back I went regularly kart racing with my little brother. He is just as tall as me, but he weighed about 70 kg, while I was at 78kg. We drove consistently the same lap times. Then I started bodybuilding and put on 20kg over the next two years. At that time we both knew the track well and were close to the optimum and the laptimes of the professionals. My brother improved his lap times only slightly over the two years, while my times got worse and worse with every kg I put on. But now comes the part that proves your theory right. After those two years I lost interest in bodybuilding and lost 15 of the 20 kg in one year. We also stopped the kart racing just before I reached my top weight for a long time until a month ago, when we went again. After a few laps of getting used I beat my own lap record from years ago when I weighed 78kg. So my skills improved, while my increased weight(especially the upper body weight) cost me acceleration and cornering speed.
Great test! But could you try to do the same type of test on a real (outdoor) kart circuit? These indoor circuits usually have a quite slippery surface and short acceleration distances. I think the difference would be much more noticeable on an asphalt track where the light guy has decent grip anyway and where you do need top speed and acceleration through long bends...
Heavier karter will struggle off standing start. Will have to brake earlier and accelerate later. Only advantage would be first few laps as tyres would be gripping earlier. Or in wet conditions.
I was karting against people about 70kg lighter than me today and while I could keep up or make ground in the corners, they'd just drive away from me when accelerating out of slow speed corners.
I think that there are a few things that have been missed here - The standing start, i race in multiple championships using corporate karts/hire drive. i currently weigh 56KG which is heavy for a 10 year old (i am 5ft2 and have size 9 feet). Every race i am in, i lose at least 4 - 10 places off the start as there are drivers that weigh as little as 25kg. These are adult karts used to carrying the weight of the kart and bigger drivers, In Bambino, Cadet or Junior series this is amplified. In virtually all forms of motorsport there are minimum weights, apart from corporate karts/junior racing - how many talented larger kids have been dismissed as not having talent, because they are not as quick as the kids that are half their weight... i have to battle constantly to recover places, be super smooth to maintain the momentum and work hard to win races. I feel so strongly about this as i have 2 friends who in the rain were untouchable, have given up racing as they can't compete with the small kids... this to me is fundamentally wrong and accepted by all. I hope the extra skills i have learnt will put me on a good footing when i step up into seniors and can race my Rotax (with minimum weight next year)
I did a couple of years 100cc 2 stroke racing about 30 odd years ago. The adult class was handicapped by adding lead to reach compulsory minimum weight. A few tenths a lap is a huge difference when racing - the juniors, with same engines, smaller chassis and obviously a lot lighter anyway were faster. I'm now 13 stone and cannot compete with much lighter decent drivers. I know - go on a diet. I'm also 64 but I don't think age is really a factor in short races. Having said that, the second of 2 X 15 min sessions does take it out of me.
This is instrumental to me because I want to do this at 230 Lbs and 57 YO. I no longer feel my weight is an issue. In fact, I'll have more experience with the weight then one guy simulating that weight. I am going to look into this because as a younger fellow, I had great lap times doing the same thing in lesser carts.
Very cool and interesting test, but it could have been much more representative. You would need to shift a lot more weight higher up, as Jack mentioned. That drastically affects your Center Of Gravity, or CG (especially in a very low Go Kart) and decreases performance more than strictly adding weight low down near the existing CG. They put the weight on the seat, that is fine, but the rest should have been strapped to their body and upper chest to be honest. How much more weight are a fat persons feet and tibias, versus their ass, gut and chest? Trust me, Im an engineer. That may also be why I am so harsh on their overall great experiment. Honestly, probably more lilke 0.4 of a second. You need to also account for the fact that (especially Jack) will be doing on average faster laps on his 2nd stint as you grow more comfortable driving around the track.
As an engineer here is something interesting for you. In karting you narrow the track (width) of the kart to increase grip, because that loads the outside tyres more and gives them more bite. Similarly to gain more grip you want weight up high, a lot of drivers add weight as high as possible on the kart in low grip or wet track conditions. Who'd have thought!
You also have to account that with the added weight placed on the seat's surface the seating position stability/comfort is hindered, which actually contributes to higher lap times. Meaning the actual time difference is even lower. However I agree that the second weight should have been strapped to the chest with a vest in order to mimic the increase in upper body weight.
@@schumifan78 The coefficient of friction for rubber is highly non linear. I would expect there to be an ideal range for this phenomenon. While the experiment definitely has some flaws e.g. not using scientific method etc it is interesting enough for it to show that the difference in weight can be mostly overcome by driving ability.
This has actually made my day, it means that weight adjusted I had the lap record at my local track since I was 7 stone heavier than the official record holder and I got within a tenth of his time !!
Perhaps the better grip and more inertia that results from the added weight, if handled proficietly, compensates enough? I am sure though that there is a cut off point also for adding weight at which point the added grip and inertia, even when handled by a master, will not be sufficient to compensate for the slow down of the engine having to do too much work against gravity and friction.
Now to prove this even further and get better differences..... go to another indoor track with lots of little corners and hair pins and do the WEIGHTED lap times FIRST and then take the weight off. Your weighted 2nd session lap times probably increased as you had already warmed up with the non weighted before hand. I reckon it would be 0.300-0.400 difference.
Such an interesting video. I used to race shifter karts AT 240lbs, which is a biscuit from 110kg. I thought that these might be the results, and they made some great observations regarding the handling of the kart. With my weight, I could jack the inside wheel off the ground 6 inches and the turns would be so brutal that they would pull your eyeballs out sideways. My racing partner weighed 60 pounds less than me when we raced we bolted 60 pounds of scuba diving weight to his seat and frame so he could race in the same class as me. I was always competitive with him for the first half of the race, but come the second half, he would drive away from me. It didn't come down to anything other than what our bodies could physically handle. A 240 pound body going around corners and a 180 pound body with 60 pounds of weight strapped to it are two different rides!!!
Our "local" Gokart track (Vandel Gokart bane) has holders beside the seat, that can hold UP to 30 kg, to exual out weight, so this excuse is taken away.
meanwhile the other day i went karting, there were 2 carts that were 20kg difference in weight. the lighter one being without the bumpers, and a bit stiffer, same engine. The difference was 38.6 vs 35.7s.
As i am pretty big guy i still can keep up with the small ones. I loose at the start or in slow climbs but noticed that i can go faster in high speed corners. Also my braking points and kart placement are different so i will carry as much speed i can through the slow corners. I can even beat my friend who is about 35kg lighter.
rental karts have solid chassis but a bit weak, which create some ondulation / resonance in some part of the track which reduces grip, my theory is that if you're too light, the resonant frequency is to high and detrimental to handling, adding 20kg might bring you to a "sweeter" spot. The kart must be tuned to an average joe size and if you're under you may be handicapped in terms of handling.
Well it actually depends on the rolling resistance (and wind resistance, which is negligible at hobby karting speeds). Theoretically, a heavier kart will be accelerated faster downhills (F=m*a --> a=F/m), but the rolling resistance will also be greater. It depends on how much the rolling resistance increases, if you will go faster or slower downhill. So no, its actually not 2nd grade physics. For example if you do speed runs in waterslides with a heavier friend he will always be faster, because for water slides, the force resistance does not increase as much as the added acceleration force caused by the weight.
@@1olp1 isn't the fat friend slower because he got a greater sliding resistance. Because he has more skin and therfore a bigger surface that has to break traction. And I thought the weight isn't even effecter more by gravity. Cause when the weight increases the gravitation which pulls it down increases equally. And the lighter got less rolling resistance.
@@serpentires I think what you want to say is that if all things free fall at the same rate (same speed), no matter the mass, things should also slide at the same rate. And you say a fat person produces more resistance force, therefore it should be slower. You are right that he has a greater resistance force because he is heavier. But the force that pulls him down is also bigger for a heavier person (imagine if you tried holding him in place, it would be harder if he was heavier, no?). This force is calculated with the mass times gravity: F=m*g*sin(alpha), m being the mass, g is gravity g=9,81 m/s^2, and alpha being the slope angle. The resistance force is more complicated to calculate because it depends on many factors and is normally calculated based on experiments. Now to know wether he is faster or slower you need to compare both forces. If the resistance force increases at the same rate as his downforce does (eg doubled downforce means doubled resistance force), he will have the same speed as a lighter person. If it increases in a degressive manner (eg doubled downforce means only 1.5 times resistance force), he will be faster. And for waterslides, with a proper sliding technique, the downforce increases in a degressive manner, therefore heavier people usually go faster in waterslides (at least up to a certain point).
not only on slides, cycling too. freewheeling downhill you can clearly see the heavier you are the faster you go. and yes we've swapped bikes to test if it wasn't the bike's fault, still happened.
With increase in mass there is an equivalent increase in grip. Thus no matter how much you increase the weight, you'll always have the same increase in grip. Where you actually lose the speed is the fact that the engine is too weak to spin out the tires. It can't extract maximum grip which means that adding weight only increase energy required to accelerate and the added grip doesn't benefit you. The only time where added weight negatively affect all the other aspects is where you have downforce.
Being more consistent to begin with and having a better sense of control, Jack suffered less with the added weight. Our esteemed host, being less consistent and theoretically having less control skills, does not reflect the true penalty of the extra weight. IOW, this is a really fun and entertaining video, but not a falsifiable, scientifically controlled test, if we're only comparing the two drivers to each other. But Jack's results are pretty credible. I'm 6' 3.5", 245 pounds, and for me, carts are so desperately slow that little children rip by me at the start, and pretty much anywhere, unless I'm protecting my line through a corner! It's so depressing, I don't go karting! I stick with my 700hp Viper! Anyway, big thumbs up for a really fun video!
There are a few other factors at play. Due to the power/weight ratio reduction the kart is not capable of such high acceleration so you are approaching corners at a lesser speed, which might not require you to brake or raise your foot off the throttle. Also this effect would tend towards inside lines which shorten distance. Added weight is always going to be a disadvantage, but is negligible for driver weight differences under 20%.
hard to believe. maybe on the slow speed tight circuit it, it helped making the times a bit closer at our home circuit here, we race Tag 125 and difference between a light driver (Kart & Driver weight 162kg) & Medium (Kart & Driver weight 182) There is approx 4-5 tenths a lap each lap.some drivers do overlap but talking about the top 3 - 5 in each of the classes. you tend to see 3 tenths trend in both classes. most of the speed loss is coming out of the corner and down the long straight.
We have a track nearby, on a 50s laptime, it hat 7 hairpins and a hill directly before and after a double hairpin... out of the hairpins and up the hill i felt that i lost so damn much time (very tight track as well)... was kinda frustrating, when you do a cutback kinda ting out of the Hairpin before the hill and catch him up so quick untill you hit that darn hill and then hes just gone... Very cool video though! I think that a test on different corners would be awesome (like, how much time do you loose through a Hairpin, how much do you gain through fast corners etc.)
It would be interesting to try this on other tracks like Buckmore Park which have long stretches of uphill and downhill which might give different results.
Depends on the track characteristics, engine package, and track size. Under some circumstances 20 lbs is nearly no penalty. Under other circumstances it's a second per lap.
So basically what your saying is weight has no impact until your within a second of the track record. so 99% of the average joes who go to race monthly or for fun can stop worrying about weight until they get good.
I'd imagine it's track dependant. TS tower bridge has a long straight after the ramp, that's easily 5 tenths.... Well that's what im telling myself anyway. Great video though!
From my experience driving Karts (outdoor track with Karts that aren't as fast as proper racing karts but are faster and lighter than indoor karts) weight really made a difference when the difference in weight was fairly significant. my friend is shorter and has a much skinnier build vs my 6'3 very wide build. i weighed probably about 70 lbs more than him and even after finding a good line and really pushing the Kart with minimal breaking I could not keep up at all in lap time, even with more track and karting experience, but when I was running with my dad who has an almost identical build to me and weighs about the same our times were within a second of each other's. Weight might not play a significant role in fast lap times under 200 lbs (approx. 91 kilos) but I have a feeling that the more significant the weight gets, the more dramatic of a difference it makes, especially when you break the 200 lb mark because of how much more work those small tires have to do, plus the fact that I have very long legs probably doesn't help as it becomes easy to accidentally ride the brakes in a Kart.
Centralised mass low down is not very representative unfortunately. A larger rider lifts the center of mass higher making cornering more of a chore. Also lets not forget that as a bigger rider, you are forced to move the seat back, which changes the dynamics of the kart far more than the weight difference would.
Surely the weight penalty on the uphills is compensated by the downhills in general, apart from when those downhills lead into a corner... Maybe. A more accurate test would be to wear heavy suits with a more evenly spread weight, and to repeat without and and with weights again, to counter potential experience gains.
Who enjoyed this karting series!? Massive thanks to Jack Aitken for helping us out. What would you like to see next?
WTF1 pastor maldonado
More videos with lando Norris
I would like to see WTF1 liking my comment
Teamsport warrington karting please or Lando norris
Norris and more karting
“I’ve got my new timing system ready” shows calendar on his phone 😂 Jack is savage and I love it 😂
He showed september 2020 aswell, cracked me up
lmfao thats what it was thank u for letting me know!
@@PS3GT5FAN that's my birthday
Magnetic_Bull 😂
Terrific Tayles same
This irritates me because I met Jack in Montréal last year and I talked about karting and how being 90kg made me too slow but obviously now I realize I'm just terrible. The worst part is the experiment was done with the guy I discussed this with...
captaino16 aye montreal ❤️🤪
Montreal my favorite place to visit
Have done some indoor karting there. As for weight not many could beat my 130 pounds. Run Briggs Master at Mosport and minimum driver weight is 200 lbs My seat looks like Swiss Cheese and carry 5 lbs of soft weight in each pocket.
@@genedrakes686 Same. I whey around 132-134 lbs and when I went Karting with my 176 lbs dad on a relatively fast outdoor circuit in France it didn't really seem to hinder him much (even though he said so :D ). I mostly gained time compared to him while accelerating onto the straits and in the breaking zones. Not so much in the infield which consisted mostly of medium speed corners.
And me it irritates that they just took their best lap. It's obvious that they'll be making better and better laps, not to mention being inconsistant and dropping an amazing lap once a while. They should've cut out something like top 25% and bottom 50% of times and take average of the rest of the laps... You spend a lot of time making this experiment and then you fuck up with the data analysis like that.
captaino16 As Jack said, its only 0.1-0.3 because the weight was placed low, if it was a person it would probably be around 0.5s per lap slower
I'd typically agree with Jacks guess that 20kg would add 0.6 seconds. Usually I've seen that 10kg adds roughly 3 tenths. There are so many other variables though so it makes it hard to measure with complete accuracy.
On my track, which was 800m and done in 43 seconds with the beginner karts(a bit slower than club100, but way faster than rentals) we said it was 0.1s/kg/lap. The class was 100kg min. driver+kart. It's both different from class to class and track to track though.
With a heavier kart that has more horses one extra kilo will mean way less though. These rentals often weigh around 100-120kg on their own.
Hello
@@thedriftingpirate347 hey buddy.
That's the best thing about sim racing right? Can weigh as much as you want and it makes sod all difference
How do you calculate this added lap time using an equation?
Jack showing a calendar to record Matt's lap times... Pure Savage!
I work at a kart track with laptimes around 1.08, and after alot of testing we concluded that 10kg is around 5 tenths. It also depends on how much you start with 60 to 70kg makes more difference than 80 to 90kg. So i guess the type of track is also important.
I think the point they made about weight distribution plays a role.
10kg on the floor, not too bad. 10kg at 1 metre - different kettle of fish
Chilukar obviously. It’s called physics...
@@Chilukar yeah but thats the thing, we tested with lead sheets at the bottom of the seat, wich should be ideal, yet it still was 0.05 sec/kg. However we have an asphalt track wich has way more grip, so my guess is the advantage of better midcorner grip with more weight doesnt apply that much
@@Knappnax sadly physics is not obvious to most people. ☹
@@TheEvanovitch Yeah but as Jack said in the video, that would lower the centre of gravity. Most people with 20-30kg extra weight will often be taller so the extra weight would be combined with a higher centre of gravity and make the kart less stable.
At least, thats my excuse and I'm sticking to it 😜
Am I the only one who really loves the camerawork at 1:25?
props to the droneman/dronewoman
Note to self for making a move: Hire a hobo to run with a camera and a gyroscope and pretend I'm a professional cinematographer. At least your average viewer will find it beautiful.
Nice spot mate
You are not.
20 kg is like 5 AR-15
(For Americans )
Edit : thx for 900 likes and the funny replies
Ahh. I understand now.
pepe LMAO
pepe how many Snickers?
Ahh yes i was trying to find out how much this was in freedom units
Too real bruh 😅😂
I know these karts are available to the public and a bit different in terms of handling. But I worked at Ocala Grand Prix as a race mechanic for a little while . Working with the Tony Karts and Rotax. And you’d be so surprised how much weight makes a difference in the pro karts. For example the smaller drivers generally had a advantage as they could place lead weight in different areas of the kart to get better stability in the front or rear. And generally 1 pound can equal 1 tenth a lap . Which is massive . However with the public karts it’s different. It’s really luck of the draw on who gets the best kart. Especially when we switched our old public karts that were 4 strokes to the new rotax 2 stroke karts. It was essentially who had the best carb haha. Interesting to see this test though non the less !! Great content as always ! Keep it up guys !!
This karting series has been brilliant, I’m just back from Dubai and last year my best time around their outdoor track was a 1:17:3, this year its a 1:15:7 and the tips from this series helped a lot because I know I can still get that time down even more
We have testet a lot on different indoor tracks. The results are all between 0.1 - 0.2s slower for 10kg extra weight on lap times of about 30s.
Ca. 2 Zehntel pro 10 Kg auf ner 30 Sekunden (flachen) Indoorstrecke sind auch meine Erfahrung. Bei 9ps Indoor sieht das nach Strecke schon wieder ein wenig anders aus, zumindest trennt sich da dann eher die Spreu vom Weizen zwischen den Fahrern die nur gewichtsbereinigt schnell sind und denjenigen die wirklich fahren können.
Really enjoying this series! So entertaining! Keep up Matt!
P.s: Keep Jack, he's such a likable guy! :D
and add Norris, those would combine great I think
Jack is more likeable than the actual dude. Who is irritating AF.
@@dons1932 You mean Matt?
@@zoltankiss1533 If I don't mean Jack, and there are only 2 people in this video, who could I possibly mean?
@@dons1932 He's not.
12:15 skip to the results
I'm very surprised to see this. The track I go to actually have a weight equalization system, and I've used it a couple of times to compare my laptimes with different weights, and I've concluded that weight has a huge impact on laptimes.
I'm guessing that system only factors in the lower acceleration from the weight and not other factors such as added grip etc.
@@raensaeck But it's a litteral weight system, where you add weights to the karts, made to equal out the weight, so everyone weighs the same when driving.
@@Brobak And how does it handle the different weight distribution? That could be a big factor, and it has also been mentioned that depending on the track it can have a lot of difference between the effects.
Being lighter allows later braking and earlier on the throttle on exit which beats that bit of extra grip. Also, the sluggish start puts you back in the gird. A few kgs does not really make much of a difference but being a natural 110kg I am slower than I was at 90kg in a race.
extra grip from mass can never offset the extra load on the tires from said mass. cornering is still worse with more weight. that's why downforce is good, it's "weight without the mass".
@@GraveUypo depends on the track and conditions though, on a bumpy track extra weight keeps the kart a lot more planted
Had a driver 105 pounds heavier than me make me look slow in the corners . Then got my spot back on the straights and back and forth we went ! He helped lift my club kart one day He knew it was heavy but not THAT heavy! To me his kart light as a feather!
Great series, great video!
Obviously there are many more "outside influences" that will change your pace, but it was still nice to see an example of how weight can affect your times.
That affect will be different from Kart to Kart and from track to track, but it's still a good indicator.
What I feel is also a downside in karting is being tall, but you can't really recreate that.
Being tall gives you more drag first of all and second of all you can't adjust your position in the kart to help your driving style. You're basically forced to sit as far back as you can to have room for your legs. That weight distribution can affect the times quite a bit as well I think. I would be intersted in you trying out different positions with the seat of the kart and see how much it changes your times, because the position can change the kart from understeer to oversteer really quick.
But overall thank you for the great content with this series!
Drag means very little at such low speeds.
If you're tall you sit further back for good rear-end grip but can lean forwards it times you need more front end grip. If you're short (like me), you have less control over weight distribution. Being tall gives advantages.
Im 5.5 and in every kart I use i have to put the seat as close as I can to the steering.
this leads to have all the weight on the front of the kart and sliding everywhere.
I lose around 1-2 second a lap just for this issue.
So your telling me I can be fat AND enjoy karting! 😁😁
Yeah boi!
Only on the corners, though...
@@don_k20 but look at the 2019 F1 season, power does not mean you are the fastest around the track 😎 so let us fatties have our moment 😂
TheBigBLT09 Nah...
It’s like the time when Alonso was in McLaren: The car’s good enough on the corners but shit on the straights.
Not if ur gonna race against 90 pound 12 yr olds
I regularly race @ Teamsport (Harlow) and there is a group of around 10 of us that vary in weight and age (55-80 kg/14-50) and we are all with 0.4 of a second of each other week in week out. The main issue with their tracks is: once you know the line its very difficult to overtake. Still great fun though, the leaderboard is very competetive but it does put off the newer racers. We often see people turn up for a race, get annihilated and then never come back. It took us months and a lot of £££ to get up the leaderboard.
Good vids, would love to see you visit some other tracks (or at least Harlow!).
Disco A fellow Harlow driver, hey! I've only been there once but it's bloody good 😛
@@cleanycloth Yup. Very grippy, physical track compared to the other Teamsport tracks I've raced. You should come to Track Attack on the 30th (4 x 20 min races). One of the best events they do.
"In formula 2 we all have to be on the same weight so I would think that would have been proof enough'
Mate if I lived neqr harlow I would straight up head down to the track right now and blast you all off the leaderboard within 10laps and I'm sorry but that's just a fact.
What is your fastest time mate
Regardless of weight differences all things being equal otherwise, if you're only running 0.10 seconds off of Jack's best lap, I doubt you're losing many races to your buds. Solid driving from both of you guys.
I refuse to accept this reality.
Friction Force scales linearly with the normal weight ie more weight = more friction between the tyres and surface.
The losses are really only due to acceleration and braking. My mate is 10kg heavier than me and regularly puts down better laps; he is just a better racer. It only really matters on the grand scale of larger circuits with lots of acceleration and deceleration
@@ItsThatMilkshake Well you get more grip with more weight, but not linearly more grip. The tire graph for grip over downforce is not linear, but degressive. So you actually will not be able to get around corners as well as with less weight, because the added grip through the downforce will not make up for the added lateral acceleration force (F = m*a). Same applies for acceleration and braking. The added momentum through extra weight will have a greater effect than the added "friction". So the losses are not only due to acceleration and breaking, but also due to less maximum velocity in the corners before the tires lose grip. Granted, the effects in hobby karting wont be too big.
@@1olp1 Finally some proper physics.
They added mass and lowered the centre of gravity. If they'd worn weight vests they'd get more realistic results.
😂😂😂
Really depends on the track. I also tried it with 10 kilo's extra on a track without elevation change. I was 3 thenths slower. And I have 6 years of rental kart experience so im not a complete fool.
Max van Laar 6 years of just rental isn’t much, you probably haven’t learned the level of adaptability needed yet - the track where I work shows pretty much the same kinda stuff as this video does
Did 3 solid years of indoor . Then in a 7 year span did 10 seasons at 2 different tracks for Arrive + Drive with a added 3.5 seasons as a track marshall for A+D and club races. My last 3 years was as a kart owner for Briggs Masters.
For indoor time did alright against various drivers from total idiots to pro racers . For the outdoor A+D I rarely missed the podium as I was the lightest driver.
Being a kart owner a whole different story! Day 1 with no weight was 2nd fastest by .068 . After adding 65 pounds being in top 10 was like a win. As for being my own mechanic I really suck! The very last race I did with my kart made sure I qualified last and pulled all the weight off for the final. The kart felt so much better !! At the end of the day if a good time was had and a repair bill of zero then all is good! Plus was a washed up never was when found out what I was "good at " Most ready to retire at 35!!
I weigh 90 kgs and I hope I can get that down to 70
@@christianj.a.8787 you can. I was 93 kg and I went down to 72.3kg. Just have a calorie deficit and be consistent with it.
@@user-of2zr6mb9o how long did it take for you to do so?
Possibly that your lap times improved as you were getting accustomed to the track. You should have backed it up by removing the weight again
it may be also difference in humidity of air and track temperature... at certain threshold values the public go-kart venue can go like +-1s within couple of hours (only few venues do change so massively, but consistently over years I was racing/practising there)
(my experience comes from over a decade of indoor amateur karting, doing races over most of the venues in Czech rep. and states around)
So doing one more run without weight right after the weighted run or at least showing how much apart those runs were would be nice.
But from my experience (being now 93kg with helmet, and when we are racing at venues with option to add weights, we add up to base weight 85kg, so I'm still +8kg to others), I lose massively more time from me being bad driver, than from the weight. Although in some venues with longer straights, in race, the exits from corners are a bit depressing, when you are at same speed going out and at certain point their kart goes just a bit faster and gets 1kart length advantage... But before blaming your weight for results, unless you are pro-driver level, there's probably another 1-2s to gain just in "your hands"... :D
They did several videos before this one, so they are fully familiar with the track
Try this at Buckmore Park and then share the results
I was searching for your comment! Keep up the amazing content man
TRL Limitless 100%
Any serious kart track it’d impact more than 2 tenths
As a heavy karter, all those 180 deg corners at buckmore are the stuff of nightmares. Was my worst track easily in BUKC.
Or rye
Einar Iliyev when I did buckmore in Honda cadets I loved it specially down the hill
@WTF1 We did this at our local E-karting track here in the states. We set tire pressures, alignments and had one of our fastest drivers compete against myself and the results of him at 120 vs me at 150 was split by a 23.5 and my own 23.7. Once we added weights just like these I ended up running a 23.7 and he ran a 23.8. Our top guys are all very consistent and the battles are close. We are talking about adding weights to the U.S.A. E-karting championship to balast the weights and also have weight classes since it does make a slight difference, and that slight difference at the top of competition makes a significant difference. Glad you guys covered this!!
Excellent series. Enjoyed thoroughly but no longer do I have an excuse for coming last.
Martin Hubz ha ha.
I think it would be more realistic if you had tied the weights to Jack's belly
Boti Gamer yes. Take his shirt off
@@alexthomson2246 That's exactly what I was thinking. Jack is too sexy for his shirt to stay on
You hitting on jack?
Martin thats exactly what I’m doing 😏
"It is not as fun if you weigh 110 kg"
Me: *weighs 110kg on my own*
yeah, same. i'm about 115 kg. consistently lose to my younger brother at karting by about 0.9-1.2 seconds a lap, he weighs 65 kg.
Hugs. At least you're a guy. It does not help your mental when your peers are half your weight and they are the standard in life and not just in karting🙆🏾♀️🤣
Bruh and there’s me who’s 60kg with full race kit
115kg here!
I actually thought they would both add up to 110kg, that would've made more sense to me
Cool, but.... With no added weight you would have improved on the second set vs the first due to practice. You should have alternated a few times.
So you're saying that I can still be an f1 driver at 102kg. Lovely 😂
We might need some lubrication to get you in and out of the cockpit but don't let that stop you living you dream
@@DjDolHaus86 😂😂😂 not fat, just big boned 😂
@@seth6526 I'm fairly hefty at 6ft/95-98kg (also big boned) and I barely squeezed into a F1 2008 replica cockpit, there was no seat so I could get my hips in but my shoulders were uncomfortably pinched and once in I was wedged and couldn't get back out
@@DjDolHaus86 I'm just a weird shape in general. I'm not fat (as in flabby with rolls 😂) but have chunky legs, a wide pelvis and shoulders and a long body and 6ft 1 so I'd have no chance 😂
@@seth6526 yeah sounds like you're a similar shape to me. The modern cars are much bigger though so you never know 😉
6:15 "he's probably going to be sliding around a lot more"
*screeching intensifies*
8:40 it doesn't keep you more planted, there is more force going into the ground but there is also more force pointing outward from the direction you're turning, countering any benefit you could have from the extra mass.
What about the extra heat generated into the tyres , maybe that could be a factor .
@@jeremygoodall could definitely be, i'd be interested to see the difference on an outside track, and maybe wet vs dry conditions.
"Weight is not such a bad thing... you've got the rear to play around with."
My mate, around the curves.
Quite the lady’s man. I’m picking up what you’re putting down, my friend, and I totally agree.
DO THE SAME TEST IN AN MORE OPEN OUTDOOR TRACK WITH LONGER STRAIGTHS , SURE THE GAP IS ALOT MORE
Depends on whether you use the 4 strokes or 2 stroke karts too, 4 strokes are like turbo diesels with good low down torque and don't rev high, 2 stroke karts require more skill to drive where you have to keep the revs up to keep in the power. 4 strokes are better if you are heavy but in the end the lighter driver will always have an advantage with a faster kart
About 4-strokes. If straights are connected with hairpin turns, yes you will lose more. If they are connected with longer, rounder turns, you might gain time instead of losing it. No idea about 2 strokes, never driven one of those.
@@PavleSmiljanic in rental karts weigth never help , untill you weigth 40kg
Ok but 2 years ago my weight was 100kg now im 72kg and at my local go kart (on asphalt outdoor karting) my time is 1 seconde quicker and I’m really constant when I’m driving so I think it’s dépend of the track, surface and kart spec maybe
Im on diet to improve my times at local automobilclub ;)
Woefully unscientific. Do a drag run over a certain distance with one kart, and then add 20 kg to that kart and time it over the same distance interval, it will be slower. This would actually be a great test in rental karts because there's no manually operated clutch and they aren't powerful enough for wheelspin, so you'd just floor it and go. This is true in any vehicle, look at all of the cars, motorcycles, etc. that have the same engine with the same tune and the heavier one is always proportionately slower. F=ma, it's physics guys.
On a track like this, how you drive it, how warmed up the kart and tires are, etc. matter a great deal. Also the kart setup matters as having weight in certain areas can fix over or understeer, and tire pressures will favor lighter or heavier drivers as well as a tire with too much pressure may have a smaller contact patch with a lighter driver, but might buckle and hop with too heavy of a driver on a lower pressure tire.
On a cold track with a cold kart, a driver 100 lbs lighter than me might not run faster than my typical lap time, but then once the track and tires are at ideal temps (which takes lots of people running the track for at least about 30 minutes on rental karts), I will no doubt beat his cold time, but he will have run even faster in the warm conditions all else being the same in ideal conditions. I've seen times vary as much 2-3 seconds on a ~35 second-per-lap indoor kart track between first session on a cold track and a warm session at the end of the day with consistent drivers that can lap within a tenth of a second every lap. If you're 5 seconds off it's your driving (or a dud kart), but on equal karts a 20kg lighter driver is going to run 0.5-1 second faster depending on track length and complexity, I've observed this at literally every league race I've ever been to that had different weight classes. And don't tell me "oh, it's because the light drivers are just better", not only are the heavier guys usually older with many years of racing school, track days, and even wheel to wheel racing under their belt (compared to many light drivers who are teenagers and haven't done any of that and barely have a basic driver's license), but when the track does a special configuration that nobody has seen before just for a league night, the heavy guys are usually faster at first because the light drivers don't have the real skills and knowledge, and only after they've put in a ton of laps (or followed a heavy driver to learn the line) do they start running faster. This video is nonsense.
To reiterate and conclude: weight matters. More than a second on most tracks is likely the fault of a driver, but a substantial weight difference will matter all else being equal and the 2 tenths shown here probably has more to do with warming up the kart/track before running the heavier lap. Gather all of the fastest laps for the year in each weight group and you will ALWAYS see a gap between weight segments unless there simply aren't any good drivers in one of the segments.
Formula Ultralight wow you must’ve got bullied hard in high school, imagine u weren’t at many parties.
But you're oversimplifying things. Engines perform best at certain loads and have certain limits on accelerations unrelated to mass. Tires are also highly non linear and respond differently to various loads, temperatures, conditions and more complex interactions. While this video is quite unscientific it's more about showing that there's still a lot you can do to improve before you blame it purely on weight
Best post and good arguments mate:) also adding extra weight so low in a kart lowers the COG(center of gravity), thats why it feels more planted. This test was rubbish.
Now do this at an outdoor circuit and see the difference. Indoor tracks aren’t too dissimilar to wet conditions where weight does help
I don’t care what you bring up next as long as jack is still in it 👍🏻
You guys are great anyways but jack brings the extra sparkle :D
When it comes to lap times, usually the difference is minor, but when it comes to acceleration and braking for overtaking and defending, that's when weight may be a problem.
Added grip from extra mass never exceeds the required grip to overcome the increased inertia!
Quite surprising results anyway!
the way they added the extra mass has a way lower center of gravity than the weight of just being a larger person (as in both taller and/or fatter). to be 100% fair they should have added 10kg on the seat and wore a 10kg weighted vest.
Not to mention larger riders typically have to move their seat back, which further disturbs the center of mass and moves the weight closer to the rear. @@GraveUypo
Jack Aitken is very good on these videos and in general explaining F2 and F1
its because of the floor, its greesy and there is no grip. So more weight helps with that. but obviously the accel is effected
great series! I really enjoyed it. Maybe outdoor karts with higher speeds next time?
I actually went to that exact track when I weighed 140kg and my best time was 59s!
i weigh 100 kilos and when go karting with me friend that weighs 70 our lap times were two tenths away from each other i was slower so we decided to do a standing start together and we found that in the corners i kept up with him but on the straights i lost a lot of time both same hire karts.
When you think about it 2 tenths is a lot faster because that means you lose 1 second every five laps
aye. that in a race at Clay pigeon, for example, people would be behind the front runners by a good lap and a half...
Cheers, I don't have to feel too bad about being 57kg now! Was nice to see how weight affects the flow & style of driving, been to teamsport docklands once with a friend who's something like twice my weight, best times were 49.7 vs 51.4. I did put this down to the weight difference & more so the lack of power because we've always been quite closely matched otherwise in cars & sim racing (where he's quicker a lot of the time). We would likely be closer with two strokes on a quicker track, IIRC there wasn't such a large difference when driving the more powerful club karts at another outdoor venue.
Weight doesn‘t impact your cornering. If your weight increases by 20% your grip increases by 20%. But also the centrifugal Force increases by 20%. It evens out. The only thing you will have is slower acceleration. Braking is the same. Again, 20% more grip while breaking, but also 20% more force pushing you forward. Evens out. I‘m shocked a f2 driver doesn‘t know this. Its one of the first things you learn in mechanics.
Edit: Not entirely true, look into the Comments for more information. I didn‘t took tire load sensitivity into account. Thanks for correcting me.
Totally wrong. The coefficient of friction is reduced with increased vertical load (weight or downforce). That is called the tire load sensitivity and it is the fundamental principle behind car dynamics (and the reason why anti roll bars and suspension stiffness matter). Engineering explained did a nice overview of this: ua-cam.com/video/kNa2gZNqmT8/v-deo.html.
ASJC27 Thanks for the Information!
@@ASJC27 Not only does the load decrease the coefficient of friction, but it also is more mass that needs to change direction. I'm baffled by these people thinking weight doesn't matter, go drive an empty car and then one with a car full of lead and tell me which is faster and corners better, even if you beef up the suspension to compensate for the extra static load.
ASJC27 So i‘ve looked at the video, very interesting indeed. I didn‘t know the fact that the coefficient of friction decreases with load. I always got told the correlation is linear (we didn‘t talk about vehicle dynamics). But, he says in his video that the coefficient of friction is fairly stable up to a specific point where it drops off. In his example he doubles the weight of the vehicle. So we don‘t know how the tires of the cart behave with 20 kg added weight.
Formula Ultralight With a changing coefficient of friction, yes, of course cornering is going to be worse. I admit I didn‘t know that. But i‘d like you to explain to me why weight does matter, if you assume the coefficient of friction is constant. Because if you set up the equations assuming that the coefficient of friction is constant, the mass cuts out and isn‘t in the equation anymore.
Baring from tire overheating, weight doesn't affect cornering speed. You get extra grip from the extra weight, but you also need the same extra grip to pull the same lateral g force. The same goes for braking. Weight doesn't affect your performance when mechanical grip is the limiting factor (cornering, braking, and accelerating out of corners where you can't give full throttle). It gets more complicated when you consider weight transfer but that's negligible on a rigid-frame go kart.
I went karting a few Sundays back, I actually thought my 17st+ was holding me back, but I suspect I'm just a bit shit at it instead.
Oh well. 🤷♂️
As a rule of thumb, for traction limited racecars, 10kg adds 1/10th of a second every 750 metres. So, for a 3km track, if you somehow find a way to make the car/driver combination 10kg lighter, you should see a 0.4s improvement in lap time, all other things being equal. Likewise, 10kg of success ballast should slow a car/driver down by 0.4s/lap.
In indoor karting, funny things can occur. 10kg is a lot of extra weight for a 9hp engine, but it's also a fair amount of weight with regard to the total weight. More weight pressing down on the tyres also equals more grip. This track is quite slick, so if there were places where Jack couldn't quite carry the speed he wanted, that situation could be improved, allowing him to negate the hit in accelleration he'll undoubtedly take.
Let's watch the video and see what transpired on the day.
Add 200kg and see if it adds 2 seconds.
Worth mentioning what I have noticed.
On some slippery tracks with not to much accelaration needed out of corners -> more open corners
I have noticed that you can be to light weight -> les grip in corners.
I was for a long time wondering why my brother 85 kg could go trought that open long corner so much faster without sliping like me with 68 kg
After some research and talking with the track ceeper he stated that he noticed that every track has an somewhat ideal weight, I added 10 kg and have improved my times on that track, because I now can take that long open corner way faster without slipping.
Can you please make a BTS video? I want to see those guys running with the camera rigs... to get those awesome shots!
Pretty much as expected. The difference is smaller in rental carting than real racing due to the hard hockey puck tyres. The increased weight get them up to higher temps(with some increased grip) , which ofsets the extra weight quite a bit.
*Hello I have a very serious&personal question: Im really tall. About 203 centimeters. (And bit more than 90kg) I feel like being tall also really affect your laptime. Because you have to put your seat and pedals really far from the steering wheel, so you have a worse weight balance in turns (I mean "I lost the rear" more than my friends who are smaller). Also being tall, you have much more of your body parts "outside" of the kart, I also feel like it is affecting your weight balance (and maybe your aerodynamic..?)*
*So being tall and by the way being heavier adds a lot of tenths at your laptime, isn't it? So how to compare yourself to your friends?!!*
Really big issue here. I hope someone could say if some of the things I said are true or false. Thanks.
Great video!
Hey man. Obviously not Matt or relate to WTF1, but if you haven't look up former F1 driver Alex Wurz. The Austrian recently had a very nice beyond the grid podcast episode and he talks specifically about this, he isn't as tall as you, but he's still too tall for the usual standard of F1 driver size, which as a particular problem he talks about when he had to go into a 2005 McLaren for a race and the car was not at all made for a man of his frame. Not to spoil it, but basically he had to compensate his size/weight disadvantage (which there is, mostly due to weight as his size was accomodated as long as the designer considered him when designing the car)by working harder at the engineering/setup side.
Mark Webber is also a "tall" F1 driver who took his talent as far as it could, but in some seasons he looked unhealthily thin.
@@zeroelus yeah ok. Now you reminded me an interview of JE Vergne where he was also talking about his tall issue. When he was in Toro Rosso he had to put a less "thick" seat to not have his helmet right on the air intake above his head. So he said that he had sometimes backpain due to his driving position..
Sad
You got normaly(depends on chassi) better weight balance in turns, how strange that sounds..... gokart shall run on three wheels in turns...
You get more aerodynamic losses.
@@flygrc Oh interesting ! Thank you for helping me to understand.
I can assure skill is > weight I went sitting for the first time ever today and was the lightest on the track by at least 50lbs+ and was still getting lapped until I figured out the track and speed and breaking and all that.
This is why kart classes have weight classes, too many variables here
8:40 You might be more planted (stable over the bumps) but that’s not downforce. Any increase on cornering friction is offset (and a then a bit) by the increased inertia refusing to be cornered.
Downforce gives you the cornering friction without the added inertia. If you have downforce adding weight reduces the effectiveness of your downforce because the downforce is making up less of a percentage of the pressure on the tire. F1 downforce would be unnoticeable on a bus but on a light F1 car it’s very noticeable.
In a similar way adding mass to a light car will reduce its power to weight ratio more than adding mass to an already heavy car (see the results of this video).
The weight being lower will help with stability.
there may still be a bias as when you have been timing the benchmark, you usually improve the more you drive. you could have warmed up the karts and got used to the kart before starting the test, so it would be a fair test
Jack Hughes if you’ve got experience with these A+D karts you’ll know that warming up only helps to a point besides experienced karters don’t improve much (it’s clear these guys have been before / had many practice laps)
@@saltbjorn not true I kart regularly. I'm always quicker in my last stint. Know someone who holds lap record at a few tracks he said the same
Henry Walter I race semi professionally mate, if you’re always quicker in the last stint that means you as a driver are still improving whereas someone like jack wouldn’t be still improving
@@saltbjorn Or learning the circuit. For example it took Jacques Vilkeneave years to master Monaco and Hockenheim when he came to F1 after Indy Car
Henry Walter that’s a him problem then
My guess is that there are a couple of different factors at play some an an advantage some disadvantage. For example at turn in the extra weight will give more grip against the extra inertia. Which is more affected probably depending on the steering angle. Then there is the polar moment of inertia which affects how quickly the kart pivots around its centre and how responsive it is, how stable or twitchy it is. Then there is the centrifugal force once into the bend versus extra grip afforded by the weight. I believe centrifugal is exponential with regard to speed whereas weight is linear. Each factor will vary in significance at different parts of the track.
Of course weight matters. If it didnt there wouldnt be ballasts in professional racing.
i heard 10kg is worth a tenth in formula one. let alone in kart racing.
@@GraveUypo I believe it is much more than just a tenth.
The weight is added very low, and seat is not moved. Normally if you weigh 20-30 kgs more than your competitor, you're also 4-8 inches taller - and your seat shifted all the way back. I bet the impact had been bigger, if seat was shifted back a bit, and weight added to shoulders.
Great series on karting BTW - big thanks for this!
Still feels wrong. Not sure about this analysis. Also, where to place extra weight does affect balance through corners. Extra weight does affect time to top speed as well as beating inertia. Shouldn't weight interfere, there'd be no need for drivers to weigh in before and after races. Do it again, only now make it outdoors with long straights.
Also, 60+20 is a 33% increase in weight. 90+20 is a 22% increase in driver weight.
I’ve done a fair bit of kart racing at club level and my theory about carrying weight on ones body is that upper body size is the biggest factor as opposed to overall weight. This in my opinion defo slows you down as this weight is less centralised and thus means there are more cornering forces on your upper body and also to a lesser extent a greater upper body mass means more drag. This test didn’t rally factor any of this in, but agree that we all have used extra weight as an excuse for our shite driving skills, myself included 😂
I totally agree. A few years back I went regularly kart racing with my little brother. He is just as tall as me, but he weighed about 70 kg, while I was at 78kg. We drove consistently the same lap times. Then I started bodybuilding and put on 20kg over the next two years. At that time we both knew the track well and were close to the optimum and the laptimes of the professionals. My brother improved his lap times only slightly over the two years, while my times got worse and worse with every kg I put on. But now comes the part that proves your theory right. After those two years I lost interest in bodybuilding and lost 15 of the 20 kg in one year. We also stopped the kart racing just before I reached my top weight for a long time until a month ago, when we went again. After a few laps of getting used I beat my own lap record from years ago when I weighed 78kg. So my skills improved, while my increased weight(especially the upper body weight) cost me acceleration and cornering speed.
Great test!
But could you try to do the same type of test on a real (outdoor) kart circuit?
These indoor circuits usually have a quite slippery surface and short acceleration distances.
I think the difference would be much more noticeable on an asphalt track where the light guy has decent grip anyway and where you do need top speed and acceleration through long bends...
Heavier karter will struggle off standing start. Will have to brake earlier and accelerate later. Only advantage would be first few laps as tyres would be gripping earlier. Or in wet conditions.
10:25 "I cannot WEIGHT to see the end results."
I was karting against people about 70kg lighter than me today and while I could keep up or make ground in the corners, they'd just drive away from me when accelerating out of slow speed corners.
Matt instead of jack is also +20 kilos
I think that there are a few things that have been missed here - The standing start, i race in multiple championships using corporate karts/hire drive. i currently weigh 56KG which is heavy for a 10 year old (i am 5ft2 and have size 9 feet). Every race i am in, i lose at least 4 - 10 places off the start as there are drivers that weigh as little as 25kg. These are adult karts used to carrying the weight of the kart and bigger drivers, In Bambino, Cadet or Junior series this is amplified.
In virtually all forms of motorsport there are minimum weights, apart from corporate karts/junior racing - how many talented larger kids have been dismissed as not having talent, because they are not as quick as the kids that are half their weight... i have to battle constantly to recover places, be super smooth to maintain the momentum and work hard to win races.
I feel so strongly about this as i have 2 friends who in the rain were untouchable, have given up racing as they can't compete with the small kids... this to me is fundamentally wrong and accepted by all. I hope the extra skills i have learnt will put me on a good footing when i step up into seniors and can race my Rotax (with minimum weight next year)
Isn't added weight proportional to the mass of the car? So the lighter the car the more the 10kg will effect its time??
You would presume so.
@@BackFromTheMadeUp hot damn, and they said school wasn't worth the diploma it was printed on. Haha thanks uncle Sam.
Correct
But that doesn't take into account the non linearity in tire friction and the non linear ability of a motor to produce power under different loads.
I did a couple of years 100cc 2 stroke racing about 30 odd years ago. The adult class was handicapped by adding lead to reach compulsory minimum weight. A few tenths a lap is a huge difference when racing - the juniors, with same engines, smaller chassis and obviously a lot lighter anyway were faster. I'm now 13 stone and cannot compete with much lighter decent drivers. I know - go on a diet. I'm also 64 but I don't think age is really a factor in short races. Having said that, the second of 2 X 15 min sessions does take it out of me.
try it on a more high speed track, i guess the diff will be bigger.
it would make a bigger difference on slow speed tracks
This is instrumental to me because I want to do this at 230 Lbs and 57 YO. I no longer feel my weight is an issue. In fact, I'll have more experience with the weight then one guy simulating that weight. I am going to look into this because as a younger fellow, I had great lap times doing the same thing in lesser carts.
Very cool and interesting test, but it could have been much more representative. You would need to shift a lot more weight higher up, as Jack mentioned. That drastically affects your Center Of Gravity, or CG (especially in a very low Go Kart) and decreases performance more than strictly adding weight low down near the existing CG. They put the weight on the seat, that is fine, but the rest should have been strapped to their body and upper chest to be honest. How much more weight are a fat persons feet and tibias, versus their ass, gut and chest?
Trust me, Im an engineer. That may also be why I am so harsh on their overall great experiment. Honestly, probably more lilke 0.4 of a second. You need to also account for the fact that (especially Jack) will be doing on average faster laps on his 2nd stint as you grow more comfortable driving around the track.
As an engineer here is something interesting for you. In karting you narrow the track (width) of the kart to increase grip, because that loads the outside tyres more and gives them more bite. Similarly to gain more grip you want weight up high, a lot of drivers add weight as high as possible on the kart in low grip or wet track conditions. Who'd have thought!
You also have to account that with the added weight placed on the seat's surface the seating position stability/comfort is hindered, which actually contributes to higher lap times. Meaning the actual time difference is even lower. However I agree that the second weight should have been strapped to the chest with a vest in order to mimic the increase in upper body weight.
@@schumifan78 The coefficient of friction for rubber is highly non linear. I would expect there to be an ideal range for this phenomenon.
While the experiment definitely has some flaws e.g. not using scientific method etc it is interesting enough for it to show that the difference in weight can be mostly overcome by driving ability.
i cant wait till I can see jack driving in f1 and I can get my helmet signed
This has actually made my day, it means that weight adjusted I had the lap record at my local track since I was 7 stone heavier than the official record holder and I got within a tenth of his time !!
That's not bad
Perhaps the better grip and more inertia that results from the added weight, if handled proficietly, compensates enough? I am sure though that there is a cut off point also for adding weight at which point the added grip and inertia, even when handled by a master, will not be sufficient to compensate for the slow down of the engine having to do too much work against gravity and friction.
Because is an indoor, in the karting of my city that is outdoor the time are 2 seconds slower than without the 20kg, only brake in two corners.
Now to prove this even further and get better differences..... go to another indoor track with lots of little corners and hair pins and do the WEIGHTED lap times FIRST and then take the weight off. Your weighted 2nd session lap times probably increased as you had already warmed up with the non weighted before hand. I reckon it would be 0.300-0.400 difference.
Such an interesting video. I used to race shifter karts AT 240lbs, which is a biscuit from 110kg. I thought that these might be the results, and they made some great observations regarding the handling of the kart. With my weight, I could jack the inside wheel off the ground 6 inches and the turns would be so brutal that they would pull your eyeballs out sideways. My racing partner weighed 60 pounds less than me when we raced we bolted 60 pounds of scuba diving weight to his seat and frame so he could race in the same class as me. I was always competitive with him for the first half of the race, but come the second half, he would drive away from me. It didn't come down to anything other than what our bodies could physically handle. A 240 pound body going around corners and a 180 pound body with 60 pounds of weight strapped to it are two different rides!!!
Our "local" Gokart track (Vandel Gokart bane) has holders beside the seat, that can hold UP to 30 kg, to exual out weight, so this excuse is taken away.
meanwhile the other day i went karting, there were 2 carts that were 20kg difference in weight. the lighter one being without the bumpers, and a bit stiffer, same engine. The difference was 38.6 vs 35.7s.
+0,2 sec.. How much power these karts have? I doubt that they have 5 hp, as usual karts... With them, the difference will be much greater.
9hp
As i am pretty big guy i still can keep up with the small ones. I loose at the start or in slow climbs but noticed that i can go faster in high speed corners. Also my braking points and kart placement are different so i will carry as much speed i can through the slow corners. I can even beat my friend who is about 35kg lighter.
rental karts have solid chassis but a bit weak, which create some ondulation / resonance in some part of the track which reduces grip, my theory is that if you're too light, the resonant frequency is to high and detrimental to handling, adding 20kg might bring you to a "sweeter" spot. The kart must be tuned to an average joe size and if you're under you may be handicapped in terms of handling.
5:19 a kart is downhill faster if its lighter. weight dont make you go down a hill faster. its like 2 grade physics
Well it actually depends on the rolling resistance (and wind resistance, which is negligible at hobby karting speeds). Theoretically, a heavier kart will be accelerated faster downhills (F=m*a --> a=F/m), but the rolling resistance will also be greater. It depends on how much the rolling resistance increases, if you will go faster or slower downhill. So no, its actually not 2nd grade physics. For example if you do speed runs in waterslides with a heavier friend he will always be faster, because for water slides, the force resistance does not increase as much as the added acceleration force caused by the weight.
@@1olp1 isn't the fat friend slower because he got a greater sliding resistance. Because he has more skin and therfore a bigger surface that has to break traction. And I thought the weight isn't even effecter more by gravity. Cause when the weight increases the gravitation which pulls it down increases equally. And the lighter got less rolling resistance.
@@serpentires I think what you want to say is that if all things free fall at the same rate (same speed), no matter the mass, things should also slide at the same rate. And you say a fat person produces more resistance force, therefore it should be slower.
You are right that he has a greater resistance force because he is heavier. But the force that pulls him down is also bigger for a heavier person (imagine if you tried holding him in place, it would be harder if he was heavier, no?). This force is calculated with the mass times gravity: F=m*g*sin(alpha), m being the mass, g is gravity g=9,81 m/s^2, and alpha being the slope angle. The resistance force is more complicated to calculate because it depends on many factors and is normally calculated based on experiments.
Now to know wether he is faster or slower you need to compare both forces.
If the resistance force increases at the same rate as his downforce does (eg doubled downforce means doubled resistance force), he will have the same speed as a lighter person. If it increases in a degressive manner (eg doubled downforce means only 1.5 times resistance force), he will be faster.
And for waterslides, with a proper sliding technique, the downforce increases in a degressive manner, therefore heavier people usually go faster in waterslides (at least up to a certain point).
not only on slides, cycling too. freewheeling downhill you can clearly see the heavier you are the faster you go. and yes we've swapped bikes to test if it wasn't the bike's fault, still happened.
@@GraveUypo cool to know!
With increase in mass there is an equivalent increase in grip. Thus no matter how much you increase the weight, you'll always have the same increase in grip. Where you actually lose the speed is the fact that the engine is too weak to spin out the tires. It can't extract maximum grip which means that adding weight only increase energy required to accelerate and the added grip doesn't benefit you. The only time where added weight negatively affect all the other aspects is where you have downforce.
Now i can figure out if i'm slow or just to big (i'm not fat, rly i'm not!)
Being more consistent to begin with and having a better sense of control, Jack suffered less with the added weight.
Our esteemed host, being less consistent and theoretically having less control skills, does not reflect the true penalty of the extra weight. IOW, this is a really fun and entertaining video, but not a falsifiable, scientifically controlled test, if we're only comparing the two drivers to each other. But Jack's results are pretty credible.
I'm 6' 3.5", 245 pounds, and for me, carts are so desperately slow that little children rip by me at the start, and pretty much anywhere, unless I'm protecting my line through a corner! It's so depressing, I don't go karting! I stick with my 700hp Viper!
Anyway, big thumbs up for a really fun video!
There are a few other factors at play. Due to the power/weight ratio reduction the kart is not capable of such high acceleration so you are approaching corners at a lesser speed, which might not require you to brake or raise your foot off the throttle. Also this effect would tend towards inside lines which shorten distance.
Added weight is always going to be a disadvantage, but is negligible for driver weight differences under 20%.
hard to believe. maybe on the slow speed tight circuit it, it helped making the times a bit closer
at our home circuit here, we race Tag 125 and difference between a light driver (Kart & Driver weight 162kg) & Medium (Kart & Driver weight 182) There is approx 4-5 tenths a lap each lap.some drivers do overlap but talking about the top 3 - 5 in each of the classes. you tend to see 3 tenths trend in both classes. most of the speed loss is coming out of the corner and down the long straight.
We have a track nearby, on a 50s laptime, it hat 7 hairpins and a hill directly before and after a double hairpin... out of the hairpins and up the hill i felt that i lost so damn much time (very tight track as well)... was kinda frustrating, when you do a cutback kinda ting out of the Hairpin before the hill and catch him up so quick untill you hit that darn hill and then hes just gone...
Very cool video though! I think that a test on different corners would be awesome (like, how much time do you loose through a Hairpin, how much do you gain through fast corners etc.)
It would be interesting to try this on other tracks like Buckmore Park which have long stretches of uphill and downhill which might give different results.
good will buxton impression in the start
Depends on the track characteristics, engine package, and track size. Under some circumstances 20 lbs is nearly no penalty. Under other circumstances it's a second per lap.
So basically what your saying is weight has no impact until your within a second of the track record. so 99% of the average joes who go to race monthly or for fun can stop worrying about weight until they get good.
I'd imagine it's track dependant. TS tower bridge has a long straight after the ramp, that's easily 5 tenths.... Well that's what im telling myself anyway.
Great video though!
i just had the same question (and excuse), thank you for testing it, now I see what is my advantages and disadvantages with my 120kg.
From my experience driving Karts (outdoor track with Karts that aren't as fast as proper racing karts but are faster and lighter than indoor karts) weight really made a difference when the difference in weight was fairly significant. my friend is shorter and has a much skinnier build vs my 6'3 very wide build. i weighed probably about 70 lbs more than him and even after finding a good line and really pushing the Kart with minimal breaking I could not keep up at all in lap time, even with more track and karting experience, but when I was running with my dad who has an almost identical build to me and weighs about the same our times were within a second of each other's. Weight might not play a significant role in fast lap times under 200 lbs (approx. 91 kilos) but I have a feeling that the more significant the weight gets, the more dramatic of a difference it makes, especially when you break the 200 lb mark because of how much more work those small tires have to do, plus the fact that I have very long legs probably doesn't help as it becomes easy to accidentally ride the brakes in a Kart.
Centralised mass low down is not very representative unfortunately. A larger rider lifts the center of mass higher making cornering more of a chore. Also lets not forget that as a bigger rider, you are forced to move the seat back, which changes the dynamics of the kart far more than the weight difference would.
Surely the weight penalty on the uphills is compensated by the downhills in general, apart from when those downhills lead into a corner... Maybe. A more accurate test would be to wear heavy suits with a more evenly spread weight, and to repeat without and and with weights again, to counter potential experience gains.