I'm not sure what UA-cam is doing but I've had a load of reports of comments being deleted, often within seconds of posting. For what it's worth, I'm not deleting them and as far as i can tell they aren't offensive so i don't know what is going on.
I've been unable to post anything if I include brand names, sellers or anything of that nature. Have been trying to converse about hubs lately in a few videos and it seems I can re-post if I remove all brand names, prices and sellers, but then it's an incredibly vague comment. Glad to see you are aware.
This has been going on for a while. The thought police at youtube have been working hard on programs to aggressively delete wrong-think. It's OurTube, comrade.
One of a tiny few trusted technical reviewers. People now have a choice of relatively good value chinese brands to choose from whilst knowing they won't be disappointed. Thanks.
Nice job. The reduction in Rotational Inertia (Moment of Inertia) of your wheel also received a nice contribution from your RideNow TPU inner tubes. Their mass is significantly lower than a traditional butyl or latex inner tube. Because that mass savings occurs at the largest radius location of the wheel your choice of inner tubes also deserves a round of applause with regard to lowering rotational inertia. 👏👏👏
I have a spreadsheet that lets you see the impact of reduced wheel weight due to inertia in various situations and it’s basically nothing. not something you have to worry about. id sooner want an aero valve on the wheel.
@@timdavid9750 I've went up steep switchbacks on low profile rims and 50mm rims and definitely prefer the former. I don't care what the math says because I'm not racing and chasing watt gains. I like to ride something that gives me joy and that's a bike that feels nimble and reactive to my input.
@@happywolfie1980 I have a couple of wheelsets (low rim height in both of them, like 25 and 35mm), and a few tyres (28 to 37mm), which I like to swap around depending on the occasion, like so many womens' shoes. I have noticed this difference weight makes, rather than size/rim profile. And while I do notice some differences in speed, mainly due to the tyre compound, the only big differences I've ever felt while riding are: - Handling, it's crazy how much the wheel inertia changes the responsiveness of the bike. - Acceleration from stop (city commuters appreciate this).
I have the road version of the G45 (Drive 45D) which is a non-catalogue spec. I fully agree that this rim profile has real low inertia characteristics especially from fully stopped situations. They are really responsive and are the best profile for roads that have a mix of flats and rolling climbs. I love riding with them to my hairdresser these days 😆
60psi? i don't really do gravel but that sounds wayyy too high. i'm the same weight with the same tire size and the recommended pressure was under 30 iirc
Agreed, I run 700x40C tires at 2 bar / 30 psi, about 80kg. This is with non-tubeless tires run tubeless, but when I ran tubes for a while, I had issues if I dropped below 40 psi. The tire sidewall lists 50-85 psi. My rides are primarily on pavement, to and from the trails.
Got these with steel spokes for my Roadmachine. I paired them with 28mm Pirelli P zero race tlr. What an absolute joy to have such air volume on the rough roads. 75kg rider and pressure set at 60 front 65 rear. Super stable in winds and just as fast as specific aero wheels of not faster
I'll never get deep wheels again, I've always found shallower wheels faster simply because they're lighter rims (low inertia). However, these at 45mm deep are very light at 1300g! BUT, they have carbon spokes, only 20 spokes, ceramic bearings (they're lighter) and a fancy machined out freehub body, so I would question if the rims themselves are actually much lighter than others.
I ordered their bog standard carbon gravel wheels with OEM hubs,hav their rim brake carbon wheels same set up 4 years ago , brilliant wheels.and bought 88 front and full disk for TT setup.thats how good their stuff is.
Quick acceleration also means quick deceleration. It's part of that whole low rotational inertia thing. Heavier wheels are great if you want to travel long distances on flat, or mostly, flat wheels. That's why I have Aerospoke wheels on my touring bike, plus no spokes to break.
@@Fetherko heavier wheels will be used when you want to maintain a high inertia (prevent deceleration). Very useful on track for example or on a TT bike
@@julienlinares I don't think that making a bike heavier or wheel, just for the sake (advantage?) of the weight is usefull in any bike discipline (apart maybe speed downhill, if the tracks wouldn't be so technical...). On track and time-trial, though, additional gains in aerodynamic improvements may be more important than absolute weight. That's where the closed dish-wheels come in. They are their for their added aero performance, not for their added weight! Still they try to make them as light as possible... Otherwise they would fill them with lead of course.
Also, re inertia. Obviously, as an engineer, you understand that it is all about that feeling of how you accelerate. It is counted by the number of butterflies in your tummy in the industry. None of the stats such as speed of the acceleration per certain number of watts of effort would be able to measure that. That is all for peasants not chartered engineers.
I've been using these with 42mm Pathfinder Pro tires and have had a good experience so far. They make my gravel bike feel more like a road bike especially compared to the other wheelset I have for the bike (45mm Maxxis Rambler with dt swiss gr1600 alloy wheels)
Which formula do you use to establish that more weight around the hub than around the rim gives you acceleration benefits? Quantify it. Transfer it to Watts
The downside of low inertia is loss of flywheel effect. When you have downhill followed by a short uphill the flywheel effect really helps. Also, a high inertia wheel will maintain it's momentum through short rough bumpy sections, though if do slow down low inertia will get you back up to speed quicker. For gravel robustness is the most important attribute for wheels.
regarding the disc rotors warping - get Hope floating rotors. they're lighter, have a better aerodynamic profile, and are far less likely to warp. downside is they're expensive.
Nice review and points to ponder as always. - I'm not convinced this wheel is different enough in mass distribution to be called "low inertia". Sounds like marketing speak. (Surprised Hambini would fall for it.) Yes - we've all known rotating mass adds inertia to wheels. That's why for a century wheels have been getting lighter. - Tubed or not is a choice. Back in the day I commuted on tubes and would be hard pressed to give up their easy patchability. But after several years, several 500km+ bikepacking trips, two Unbound 200s (320km on flint rock), two BWRs, and countless local endurance gravel races, I'm no longer swayed by the "in the middle of nowhere" argument. Tubed or tubeless, carry a spare tube (and maybe old tire bits for sidewall slashes) if you worry about puncturing ITMoN. (Where is that in 2024 btw? lol) Tubeless adds self-sealing for the most frequent punctures. With all that riding I've never punctured a tubeless that didn't self-seal. Likely this is mainly due to the low pressures tubeless allows. (fwiw I run iRC tires and weigh 65kg.) 2. Those Elites look nice but I'm not into gloss coatings on a gravel wheel. As noted - it's asking for chips and dings. 3. The inner width is 24mm which is good but rolling resistance being king these days and all else equal - I'm still looking at Enve SES 4.5s for my next set.
Indeed, I also believe "low rotational inertia" is mainly marketing blabla, just to confuse people. Unless they mean that the wheels are just plain light(er), those have typically also less rotational inertia. But just because they are lighter, not because they have their weight more centralized. Lighter wheels have (much) more advantages than just having lower rotational inertia.
Great as usual. I Would love to see the DRIVE SIX model reviewed by you, explaining the implications of riding a full carbon six spoke wheel in the gravel world, regarding extreme stiffness and so. Thanks for sharing your knowledge.
Another good review thanks. Would it be possible to include a bit about spares availability and how the communication with the supplier went. What is the back up if there is an issue or when I need a new free hub. Thanks
In the meantime, I also checked the website of the manufacturer. At no place I could find any claim about their wheel construction focusing on low rotational inertia. Clearly, they do advertise their rather exceptional light weight, which in itself does result in lower energy take up to accelerate them both linearly and rotationally. Which is great! But claiming that these wheels excel in the lower rotational inertia (at least when comparing them to other wheels of equal weight) seems grossly exaggerated, and probably not even correct. In fact, most wheelsets of comparable lightweight will rather have a lower rim profile to bring the weight down, leading (probably) to even lower rim weight, and therefore leading to lower rotational inertia compared to these wheels (for the same overall wheel weight). OTOH, these wheels will be more aero (for what that is worth at typical modest gravel speeds), which is probably more beneficial than any claim on their exceptional rotational inertia.
When applying teflon tape onto pipe threads, there is only 1 correct direction to apply the tape. Otherwise the tape comes undone when you thread the nut onto the pipe. In a similar fashion, those handlebar grips are wrapped the wrong way; that's why it's coming undone.
Seems like there's a lot of confusion in the comments regarding the performance implications of inertia (rotational or otherwise)- might be worth doing a video on? The wheelset choice of low inertia vs aerodynamics is skewed for off road wheelsets vs road racing wheelsets. Speeds are generally lower and the larger, knobby tyres give the middle finger to a lot of the aerodynamic rim benefits before the air stream even hits them. For gravel bikes with suspension (or rigid being ridden out of the saddle with bent knees and elbows), Lighter wheels and frames reduce unsprung weight which makes for a smoother and more efficient ride. When you're accelerating suddenly and the frame bends instead of the bike moving forward immediately it is inertia that is stopping you (along with other forms of resistance, though these are not as relevant in that moment). Lowering your system's inertia helps the bike to zing forward- from a "feel perspective" it could be described as feeling stiffer. As hambini has stated- if you go out on the bike and test wheelsets back to back the difference in feeling is huge. However just because it feels big doesn't mean that it actually is big in terms of watts saved, seconds across the line etc. In the vast majority of road racing contexts this difference I don't believe this difference is significant, with crit racing and fixed gear street racing (where there is a metabolic cost associated with both accelerating & decelerating both of which happen frequently through big ratios) being notable exceptions. Truly though the big advantage of lower inertia is for those who aren't racing (against the clock, their strava or others) and who have lower overall power levels. These riders often find accelerating (at the lights, out of turns, on singletrack) and riding up hills the most intense and negative parts of a given ride. Lower inertia and lower weight help to reduce the actual and perceived difficulty of the ride and can help them feel more powerful on the bike- an enjoyable feeling I'm sure we can all relate to.
I’ve been on the Marvel G35 version of these due to their slightly smaller inner width, they cost me like $700 cad over a year ago and I couldn’t recommend them enough. I’ve put over 6k km on them, with probably 3k of that being actual gravel and they’ve been perfect. Looking to buy a set of 29er rims from them next, I don’t see a reason to look elsewhere. Also, Galfer discs have been great for me, I go for a lot of rides where a sudden splash or creek crossing can bring your brakes from hot to cold in an instant and they have been good, NTM made in Europe.
You should do a video on bearing maintenance from an informed engineering perspective, I find it hard to believe all if these 'bike cleaning products' such as muc off's bike cleaner etc. dont strip grease, i genuinely believe its all marketing. I've found that theres so many conflicting arguments on how to maintain bearings/your bike so it would be interesting to find out your unfilitered perspective.
@@Hambini they’ll be off the shelves for me then, cheers for the reply. I do wanna know what should be done with bearings though, grease on the outside of them/not (suspension linkage for example) because of the grinding paste effect. I’m guessing maintenance is just some hot water and a sponge. Was literally watching your vid on campag bb’s as you replied, great timing haha.
Going from a deep section budget(ish) rim down to a mavic r sys shallow rim with a 23mm tyre highlights perfectly the benefits to be gained from low rotating mass and acceleration benefits therein. I like the tighter rim.
I use campagnolo disc rotors with my shimano grx di2 brakes. I’m 90 kg heavy and had no trouble ever (including riding my gravel bike in the alps or up and down the “Großer Arber” = highest Peak of the bavarian/bohemian forest mountain range> resulting in a 18 km/800 hm downhill).
I've been said Galfer disc brakes are the dogs bolloks as far as rotors go, should definitely give them a try, I'm having so many warping problems on my bikes
Regarding warped rotors, I've never warped a straight stainless rotor, even in bike park riding where I've had then turn blue from heat. Maybe worth trying some non-Shimano rotors that don't do the steel-alu-steel sandwich? They're likely to be less expensive if do do keep having to replace them too.
Low inertia really is a thing; you almost feel like the wheels are pulling you downhill on a descent. The kicker is the front of the bike feels very unsafe in gusty winds.
Hambini have you done berd spokes vs metal spokes? Maybe also carbon, I'm curious power difference at same speed between them on road (rim and hub kept the same)
I have a set of Elite 50D road wheels. They ride great(!!), but a couple of the bearings in the rear wheel went to crap in 3 months. I weigh about 90 kg. The good news is that they sent me replacement bearings that I received about a week later. So, in my opinion a company you can trust. (But maybe a different hub design compared to the gravel wheels?)
Had a front wheel of this wheel set totally collapse last year whilst a decent in the forest. Caught a stick in the front wheel and all spokes of the front wheel broke in this accident. I'm never ever going to buy a carbon spoke wheel set for Gravel ever again. Maybe it's a good set for road riding.
60psi will be much too high for anything- even for an indoor wooden track with that setup. You're compromising your rolling resistance and comfort. Try 25psi or look at the Silca tyre pressure calculator.
Hello friend, I have a great question. When I turn the cranks I notice that the chainrings have an oscillation, as if they were misaligned or bent. crankset, crowns, and frame are new. Check the crowns and the connecting rod spider on a flat surface and they are correct, there are no waviness or bends. The axle enters smoothly through the bottom bracket, rotates smoothly. I turned the axis of the left crank mounted on the frame and without the crowns, I don't notice that the axis is twisted. Assemble the complete crankset without crowns, and you can see the oscillation movement in the spider. So I don't know what it could be, or if that movement is normal and to what extent. I have seen this in other cranks of different materials and brands and different frames that I have had, but on this occasion I see that the movement is greater.
I’m grinning to myself whilst watching this video. Several year ago when everyone seamed to by swapping out their conventional wheels for aero wheels, I did the opposite. I didn’t have a aero bike so one less reason to go aero so I purchased some DT Swiss R21 Dicut wheels at 13000g ish. They changed the ride quality for the better with fast acceleration and lightened up an already light bike. This is particularly beneficial for large riders like me who don’t give a shit about Stava times. Yeh the aero brigade had better looking faster on the flat bikes, but I had the most fun and my climbing improved overnight. The moral is, don’t be a 🐑
I've had these wheels for about a year and some of my bearings died after about a thousand miles, the rest have been fine since (9000 miles). There seems to be a lot of variability in their bearing quality.
Huh. I use those same rotors on my Roubaix. I put them on a set of Elite Drive 50D wheels, at least partially based on your review. Anyway, I don’t have any issue with them warping. My typical ride on that bike is about 6000ft of climbing, with screaming descents, often in varying conditions. It’s usually wet during some part of that ride. So I feel like I encounter some similar, possibly more extreme conditions. After a big braking event from 40mph or so, I can get some brake rub for ten seconds or so. But then it goes away. Is that what you’re referring to? Or more permanent warping?
@hambini I have a customer who walked into my shop complaining that his new wheels (alloy cup and cone generic wheels) were taking way longer to spin down than his old 1970s road bike wheels(13 seconds vs ~300 seconds to stop). I attempted to account for this because the bearings are sealed cup and cone(old most likely unsealed cup and cone), are new vs. old, etc. Needless to say he didn't buy my initial explanations. I've checked the bearings on the new bike and they are preloaded correctly. I've read some stuff on forums saying it's due to weight, and that spindown tests 'don't matter', but some of it is explained in a 'broscience' sort of way. Fundamentally, do (unloaded) spindown tests on wheels matter? If so, or if not, why? It is my guess also that wheel weight might be playing a role too(70's department store bikes are tanks). Thanks!
I guess the wheel bearings are the main factor in how long wheels keep rotating freely. Wheels with a bigger rotational inertia surely have an advantage there, as they start with more stored energy to be dissipated to zero. Though the differences will be rather in percentages and not in whole factors. So bearing smoothness will be decisive. Note that if you check this on the back-wheel, you might also get some influence from the resistance of the freewheel, surely that is also a non-zero effect on how long your (back) wheel will rotate freely. I used to have one particular race bike, when I let the (Mavic) backwheel rotate freely, it started to push the pedals around, showing that the resistance in the freewheel was bigger than the resistance in the BB+chain. I didn't mind though, as when you really need power you push the pedals anyway, and you "lock" the freewheel. So I prefer to have a smooth BB+chain above a smooth freewheel... Most race-bikes seem to have it just the other way around though!? 🤔
@@henkdevrjes9640 As if I would ever want to write for a cycling mag. I guess knowing stuff and telling the truth is not what a cycling mag would want in a writer anyway. You're welcome for answering your question.
I have the wheel since 10 months/1400km and the front bearing failed me. the inside of the hub seems dry and the bearings lubed, they sound dry or damaged from the inside however.
@gerrysecure5874 Can you give some insight in those calculations? What did you find? Were you making a difference in pure mass vs rotational inertia of the wheels?
Firstly, I do love your videos! I'm not sure whats going on though... A low inertia object is an object which is low in mass, yes? It will spin up to speed quickly. (Force, mass, accelleration) These wheels, with these tyres are heavy compaired to most. These will be considered a high inertia wheelset as they take more force to accellerate the higher mass... A set of lighter wheels and tyres would have waaaaayyy lower inertia. On the other hand, a high inertia object is of high mass which takes more force to accellate, once up to speed it may keep spinning for longer, like a heavy fly wheel. I struggle to believe from my riding experience that these wheels spin up to speed easily as you suggested. On top of this there is the massive rolling resistance of nobbly tyres. I guess it all depends what you are comparing it too, a tractor wheel or a road race bike wheel?? If I'm wrong please put me right.
When looking specifically at bicycle wheels in a bike, you need to distinguish two types of inertia. 1/ You have the wheel's pure mass ("weight"), which you need to speed up as you increase your riding speed, and 2/ as you start speeding up, obviously the wheel needs to start rotating faster (because you want to roll your wheels on the ground without slipping) , and obviously that also takes up energy. That is linked to the rotational inertia of the wheel (scientifically called moment-of-inertia). And this whole debate here is, what the impact is of this rotational inertia on the (overall) acceleration of a wheel+bike+rider. I haven't met many people that have a natural feeling for what this rotational inertia means in terms of power and energy consumption (no, neither me), but by calculation (or look it up on internet), you can find that for a wheel/loop where all the mass is in the rim, it takes as much energy to make it move, as the energy it takes to rotate it, when it rolls without slipping. The point is, that this energy is only a fraction (1 or 2%) of what it takes to speed-up the mass of rider (+the rest of the bike). So the debate is really about how much of that rotational energy is noticable, and how much difference you can feel if you take a wheel (of same weight) where the rotational inertia is lower (i.e. its mass is not just all located on the rim, but part of the mass is located more centrally). Surely lighter is always better, for both. And surely, a smaller rotational inertia itself must also be "better", but whether just this can effect your biking performance in a somewhat noticeable way, is really where opinions seem to differ.
Jan Heine in "The All Road Bicycle Revolution " claims that there is a limit to how light that you can make the rim and not experience handling problems. He noted that makes of 20" folding bikes added mass to the rim. He said that the problem should not show up on 700c bicycles. I really didn't understand his argument. I am desiring of making my 26" wheels lightweight with light tires. 300g tires for my proposal! Jan's usage of the term "moment of inertia " was a bit flawed. He equated it with inertia. They are not the same. I have been meaning to write a polite letter to him.😊 My take is that a rider loses the kinetic energy that they built up in the wheels when they apply the brakes. So, we want light rims!
What are you thinking of the zipp303 xplr. I always think deep wheels that are much slimmer than the tire aren‘t really good for aero. You could just make a shallow even lighter one. If 9 Velo or Elite etc. would make a deepish (45 to 50mm) gravel wheel with a outer width of 40mm i would really buy it. Now i think i have to wait untill the chineses brands hop on this.
An idea how much the sheer deformation of the tyre impacts acceleration? i.e changing the tyre pressure not only affects rolling resistance but also sidewall deformation.
Hello Sir, great Video! I'm in the market for MTB XC racing wheel, so I look at the weight first, then hub quality and ofc price. But what is your recommendation on 6 bolt vs Centerlock? I would go for Galfer discs, thanks!
Hambini, regarding the title of the video, does this mean that we will see marketing departments changing from 'aero' to 'accelleration' gains? This may/should also place emphasis on box section and climbing wheels/weight.
Mate, do the calcs. How much energy/power do you think it takes to spin up a wheel compared to accelerating the total mass of rider and bike, it's next to nothing. Thats why you can stop a spinning wheel in the air with 1 finger in a second. Try and decellerate the entire mass of rider and bike with one finger. The differences in inertia of different wheelsets are negligable.
Assuming the front and rear wheels weigh in at around 1kg each, if you take off 100g at the edge, you'll end up with 20 percent ISH less inertia. Let's say it took 20 seconds to accelerate that wheel set before up to speed, it would now take 16 seconds. There are some approximations in there but it removes the effects of system weight and rider power. That amount is not insignificant
If you're not going to do it then fine, see below: 75kg rider, 10kg bike, 0-30km/h in 10 seconds. Rider and bike: E=(1/2)mv^2 v=8.3m/s m=85kg E=2927J P=E/t t=10 seconds P=293W Wheel: 1kg wheel, 700mm diameter, all mass concentrated on circumferance (worst case) I=mr^2 m=1kg r=0.35m I=0.1225kgm^2 E=(1/2)Iω^2 I=0.1225kgm^2 ω=23.7rad/s E=34J P=E/t P=3.4W Total power ~ 300W, each wheel is ~ 1% of this assuming all mass is on the circumferance. Difference between two wheelsets is fractions of a percent.
Brilliant vid as usual but am a bit worried about hub internal spares availability for a lot of these new Chinese wheels Brilliant as they are. I know eventually they will probably sort these problems but how are things at the moment with Elite and 9 velo?.
Hambini, what do you think about tantan cycling bikes and wheels? They’re also Chinese and really cheap, maybe even too cheap for good standards. Do you plan on doing a review on these in the future? Really love your videos they’re well done (for a 5 yr old)
Enjoyed that, and I can appreciate your arguments for the higher tolerance fields relative to DT Swiss as a base yet can you demonstrate that in a real world case outcome with respect to say reliability and cost over time? What I'm getting at is something you said, this ain't aerospace, so if it just works, does it need to be 'that good' or is the DT swiss tolerance which is likely on the higher end comparatively to other brands, is that more than enough in a real world case. Cheers for the content.
Hey hambini - not a question about this video but would you be open to doing a video on lube / wax and your preferences / experience - keen to hear views on some of the ZFC data
Mr H, I’m a new subscriber to your show so I apologise if my question is not your neck of the woods. Cleaning bike parts in an ultrasonic cleaner - hit or miss? What do you recommend. Many thanks.😊
I am in the same boat here 😂. Either the 9velo GV 2.0 or the Elite Wheels G45 SS, but with an Shimano HG freehub, after all coupons they are about the same price. - Have you decided yet? EDIT: For 9velo I can also specify brass nipples when ordering, which is a plus, and I think the hub is quite nice, but the print on the rim was nicer in the previous GV version. On the Elite Wheels the finish of the rims seem to be quite nice and they come with ceramic bearings. Weight is also about the same...hmm
@@shannonparker7404 Dang, was hoping you already pulled the trigger on something! Yeah, so much choice... and definitley no hookless! FYI, I am also looking at the following: Winspace Lun Grapid, Nextie build with the GX NXT40GX rims and DT350SL, Farsports C3, and Light Bicycle A35 rims with DT Swiss 350. Did you find anything else interesting that would fit?
The thing that is of utmost for me is local support. I've recently been burnt by poor support from a large offshore wheel manufacturer. I'm now leaning towards getting some wheels locally built with local bike shop support. Probably DT350 or 240 straightpull hubs, CX ray spokes and I'm hearing good things about Nextie NXT45AGX rims.... And the surprising thing is they will be cheaper than a Big Brand name!@@DonnieX6
Was in the same boat. These have free shipping and with discount codes the ss version are a few hundred dollars cheaper than 9velo once you add their shipping
I've had Aerospoke 5 spoke wheels for over 20 years now on my touring bike, they are wonderful and strong and look sensational. Great for long distances on flatter terrain.
Great vid Hambini. I have a set of Elite wheels with high engagement hubs. What grease do you recommend for this type of pawl hub? There seems to be quite a bit of drag
Also make sure not to overgrease. 95% of everyone puts in way too much grease. If you put in just the smallest amount, and think it's too little, don't add more cause you probably added too much and didn't even realize it.
The mass of a wheel has two forms of inertia to ovecome when speeding it up as you accelerate: rotational inertia (moment of inertia) to make the wheel rotate (where the distance of its distributed mass from the center plays a big role), and its pure mass to accelerate it linearly. If we assume that all the mass ("weight") of the wheel is situated in the outer rim, and assuming you accelerate your bike while you roll your wheel over the road without slipping, than the energy that you will need to put in the wheel to make it rotate, is exactly the same as the energy you will need to make it move linearly (=your riding speed). The very interesting (and -at least for me- somewhat surprising) part is that these two movements (rotation and translation) take up exactly the same amount of energy in the case of (such) a bike wheel. If you manage to make such wheel lighter, you will have advantage on both these energy consumers (as your wheels absorb/store rotational energy and kinetic energy as you accelerate). For most people this rotational energy isn't very quantifiable intuitively (though, we do know that it doesn't take much energy to stop a rotating wheel), but accepting (or re-calculate if you want...) it is of the same order (well, theoretically identical) as the energy of a moving object of the same weight being thrown to you, this may give you somewhat a clue. Now, if you compare these two (equal) energy absorbers, and compare that to the combined weight of your body and the rest of your bike, which also need to accelerate at the same time at the same rate as your wheels, of course those will be the main energy absorbers of whatever your output power is on your pedals. As mentioned in other comments, you will spend less than 2% of your power to make your wheels rotate, and 98% of your power output to accelerate linearly (your body + bike including its wheels). Now if you manage to take some of the weight off the wheels, you'll be already better off, *both* for rotational and linear movement energy consumption/storage. If you make your wheels only half as heavy (say 1kg vs 2kg), you'll be able to spend about 99% (iso 98%) of your power input to accelerate linearly, and only 1% needs to go into the rotation. So you will accelerate 1% faster. If it would normally take you 10sec to get upto your desired speed, with wheels half as light, it will take you 9.9sec! Yes, 1% is small, but it could make the difference between winning and loosing. Now, assume we manage to build a wheel with the same initial weight, but we manage to shift half of that weight to the middle around the axis. There, weight doesn't contribute to the uptake of rotational energy. This wheel has lower moment of inertia, only half as much, so it takes up only half as much energy to spin it up. Compared to our initial bike, the only thing that will change is that the energy that will get stored in the rotation of the wheel while accelerating is only half of what we used to spend first. So we can use this "saved" energy to accelerate a little faster. Though, we still need to spend the same energy to accelerate the body+bike+wheels linearly. So you would be able to spend something between 98 and 99% of your power to accelerate linearly. So you would be able to accelerate to the same speed in about 9.9x seconds. Right, that could also make you win a race. Bottomline , overall weight of a wheel is more import than trying to optimize the moment of inertia (for the same wheel weight). If you have the choice between a wheel with light weight and a wheel with "improved" moment of inertia, take the lighter wheel. And to close this topic, unless you are riding rather slow (gravel?), doing lots of climbing and/or lots of of accelerating/decelerating, choose the most aero wheel first, even when there is a (modest) penalty in weight and/or moment of inertia.
@@wouterdobbelaereWhen I slam the brake while the bicycle is up on the repair stand, the whole bicycle and stand shake as the kinetic rotational energy is transferred to the bicycle. That tells me the magnitude of stored rotational energy.
@@Fetherko Exactly! And it is the same amount of energy that this wheel would have if someone was throwing it at you with the same speed (albeit without rotation), at least when the rim carries all the weight. The more the weight is centralized on or close to the axis, the less the rotational energy becomes for the same rotational speed (compared to linear inertia/energy). So, yes, surely, the rotational energy isn't zero, so it makes sense to try to reduce it further. Just that we are mainly debating here at what level of difference in total energy consumption we are looking here. Is it gains, marginal gains or non-measurable gains? The jury is still out...
How about discuss the ackchual benefits of low weight vs aero for gravel riding? As % of total mass 200g is insignificant, so we are discussing the benefit of snappy acceleration? But fast accel means fast decel too? Compare with aero where wins are real wattage all day. Is point of gravel maybe that speeds are lower so aero doesnt matter? Or are you just yanking our chains?
I'm not sure what UA-cam is doing but I've had a load of reports of comments being deleted, often within seconds of posting. For what it's worth, I'm not deleting them and as far as i can tell they aren't offensive so i don't know what is going on.
The censors must not be banging their head dressers enough!
I've been unable to post anything if I include brand names, sellers or anything of that nature. Have been trying to converse about hubs lately in a few videos and it seems I can re-post if I remove all brand names, prices and sellers, but then it's an incredibly vague comment. Glad to see you are aware.
Censortube at its best
@@lucideuphoria7092 that does seem to ring true because others have said similar things when they put in ally xpress
This has been going on for a while. The thought police at youtube have been working hard on programs to aggressively delete wrong-think.
It's OurTube, comrade.
Hey Alexa, make "Hello Hambini Fans!" My doorbell ringer, and put it on repeat.
Or your phone ringtone. (insert evil grin here)
One of a tiny few trusted technical reviewers. People now have a choice of relatively good value chinese brands to choose from whilst knowing they won't be disappointed. Thanks.
Have these wheels for a few months now. Love them. Thanks for the review.
Nice job. The reduction in Rotational Inertia (Moment of Inertia) of your wheel also received a nice contribution from your RideNow TPU inner tubes. Their mass is significantly lower than a traditional butyl or latex inner tube. Because that mass savings occurs at the largest radius location of the wheel your choice of inner tubes also deserves a round of applause with regard to lowering rotational inertia. 👏👏👏
I have a spreadsheet that lets you see the impact of reduced wheel weight due to inertia in various situations and it’s basically nothing. not something you have to worry about. id sooner want an aero valve on the wheel.
It's just nice to ride wheels that spins up very quickly, the nimble ride feel makes it worth it beyond the mathematical watt savings.
they feel like they 'spin up quickly' and that's nice. Though the maths will tell you otherwise, there's almost no difference.
@@timdavid9750 I've went up steep switchbacks on low profile rims and 50mm rims and definitely prefer the former. I don't care what the math says because I'm not racing and chasing watt gains. I like to ride something that gives me joy and that's a bike that feels nimble and reactive to my input.
@@happywolfie1980 I have a couple of wheelsets (low rim height in both of them, like 25 and 35mm), and a few tyres (28 to 37mm), which I like to swap around depending on the occasion, like so many womens' shoes. I have noticed this difference weight makes, rather than size/rim profile.
And while I do notice some differences in speed, mainly due to the tyre compound, the only big differences I've ever felt while riding are:
- Handling, it's crazy how much the wheel inertia changes the responsiveness of the bike.
- Acceleration from stop (city commuters appreciate this).
@@happywolfie1980 yep, if it feels better it makes you want to ride more
I have the road version of the G45 (Drive 45D) which is a non-catalogue spec. I fully agree that this rim profile has real low inertia characteristics especially from fully stopped situations. They are really responsive and are the best profile for roads that have a mix of flats and rolling climbs. I love riding with them to my hairdresser these days 😆
60psi? i don't really do gravel but that sounds wayyy too high. i'm the same weight with the same tire size and the recommended pressure was under 30 iirc
Yeah seems too much
Agreed, I run 700x40C tires at 2 bar / 30 psi, about 80kg. This is with non-tubeless tires run tubeless, but when I ran tubes for a while, I had issues if I dropped below 40 psi. The tire sidewall lists 50-85 psi. My rides are primarily on pavement, to and from the trails.
I'm 90kg and ride my 42mm gravel tires at 28psi. 60 is nuts😂
Seems like I always run at least 20 psi lower than whatever the side of the tire says, and it's plenty, and I'm 72 kg.
I weigh 62 and run about 28psi on 40mm run tubless. But 60 is what I'd run 28s at tubed..
Got these with steel spokes for my Roadmachine. I paired them with 28mm Pirelli P zero race tlr.
What an absolute joy to have such air volume on the rough roads. 75kg rider and pressure set at 60 front 65 rear. Super stable in winds and just as fast as specific aero wheels of not faster
isnt the minimum 30mm ?
@@telkmx They are working perfectly with 28mm tyres.
No problems at all
I'll never get deep wheels again, I've always found shallower wheels faster simply because they're lighter rims (low inertia). However, these at 45mm deep are very light at 1300g! BUT, they have carbon spokes, only 20 spokes, ceramic bearings (they're lighter) and a fancy machined out freehub body, so I would question if the rims themselves are actually much lighter than others.
The rims sans spokes and hubs are 415g each. 45mm deep, internal 24mm, external 31mm
I winced when you touched that rotor 😂😂😂
I ordered their bog standard carbon gravel wheels with OEM hubs,hav their rim brake carbon wheels same set up 4 years ago , brilliant wheels.and bought 88 front and full disk for TT setup.thats how good their stuff is.
Quick acceleration also means quick deceleration. It's part of that whole low rotational inertia thing. Heavier wheels are great if you want to travel long distances on flat, or mostly, flat wheels. That's why I have Aerospoke wheels on my touring bike, plus no spokes to break.
I still don't see a case for heavier rims. Appreciate your writing, though . 😁
@@Fetherko heavier wheels will be used when you want to maintain a high inertia (prevent deceleration).
Very useful on track for example or on a TT bike
@@julienlinares I don't think that making a bike heavier or wheel, just for the sake (advantage?) of the weight is usefull in any bike discipline (apart maybe speed downhill, if the tracks wouldn't be so technical...). On track and time-trial, though, additional gains in aerodynamic improvements may be more important than absolute weight. That's where the closed dish-wheels come in. They are their for their added aero performance, not for their added weight! Still they try to make them as light as possible... Otherwise they would fill them with lead of course.
Also, re inertia. Obviously, as an engineer, you understand that it is all about that feeling of how you accelerate. It is counted by the number of butterflies in your tummy in the industry. None of the stats such as speed of the acceleration per certain number of watts of effort would be able to measure that. That is all for peasants not chartered engineers.
I absolutely love the finish on these.
I've been using these with 42mm Pathfinder Pro tires and have had a good experience so far. They make my gravel bike feel more like a road bike especially compared to the other wheelset I have for the bike (45mm Maxxis Rambler with dt swiss gr1600 alloy wheels)
i love your nyc videos hahahah
@@Littleweenaman love you!
Which formula do you use to establish that more weight around the hub than around the rim gives you acceleration benefits? Quantify it. Transfer it to Watts
Aero is not dead. Nothing looks better then huge rims :).
Tell that to your hairdresser 😁
The downside of low inertia is loss of flywheel effect. When you have downhill followed by a short uphill the flywheel effect really helps. Also, a high inertia wheel will maintain it's momentum through short rough bumpy sections, though if do slow down low inertia will get you back up to speed quicker.
For gravel robustness is the most important attribute for wheels.
Elite Drive G45 or 9Velo Gravel Disc GV 2.0 ??
Which one shall I choose?
regarding the disc rotors warping - get Hope floating rotors. they're lighter, have a better aerodynamic profile, and are far less likely to warp. downside is they're expensive.
Or sram centerline. Or Campy ones. All much better (but yeah, Hope do look the nicest).
Nice review and points to ponder as always.
- I'm not convinced this wheel is different enough in mass distribution to be called "low inertia". Sounds like marketing speak. (Surprised Hambini would fall for it.) Yes - we've all known rotating mass adds inertia to wheels. That's why for a century wheels have been getting lighter.
- Tubed or not is a choice. Back in the day I commuted on tubes and would be hard pressed to give up their easy patchability. But after several years, several 500km+ bikepacking trips, two Unbound 200s (320km on flint rock), two BWRs, and countless local endurance gravel races, I'm no longer swayed by the "in the middle of nowhere" argument. Tubed or tubeless, carry a spare tube (and maybe old tire bits for sidewall slashes) if you worry about puncturing ITMoN. (Where is that in 2024 btw? lol) Tubeless adds self-sealing for the most frequent punctures. With all that riding I've never punctured a tubeless that didn't self-seal. Likely this is mainly due to the low pressures tubeless allows. (fwiw I run iRC tires and weigh 65kg.)
2. Those Elites look nice but I'm not into gloss coatings on a gravel wheel. As noted - it's asking for chips and dings.
3. The inner width is 24mm which is good but rolling resistance being king these days and all else equal - I'm still looking at Enve SES 4.5s for my next set.
Indeed, I also believe "low rotational inertia" is mainly marketing blabla, just to confuse people. Unless they mean that the wheels are just plain light(er), those have typically also less rotational inertia. But just because they are lighter, not because they have their weight more centralized. Lighter wheels have (much) more advantages than just having lower rotational inertia.
Satisfying to discover that my Salter kitchen scales are endorsed by Hambini
Another good reaming with stunning results. Drive it deep, drive it hard for those wheels, luvin the wheel testing👍👍👍👍👍
The lightness of the rim, which is the rotating mass gives less inertia. Spins up faster for less effort and had less gyroscopic effect.
Try these, bit heavier but quieter :- SwissStop Catalyst Race Centre Lock Disc Brake Rotor 160mm
11:50 That is basically XC widths, do you think they would hold up for that sort of riding?
Yep
Great as usual. I Would love to see the DRIVE SIX model reviewed by you, explaining the implications of riding a full carbon six spoke wheel in the gravel world, regarding extreme stiffness and so. Thanks for sharing your knowledge.
Another good review thanks. Would it be possible to include a bit about spares availability and how the communication with the supplier went. What is the back up if there is an issue or when I need a new free hub. Thanks
In the meantime, I also checked the website of the manufacturer. At no place I could find any claim about their wheel construction focusing on low rotational inertia. Clearly, they do advertise their rather exceptional light weight, which in itself does result in lower energy take up to accelerate them both linearly and rotationally. Which is great! But claiming that these wheels excel in the lower rotational inertia (at least when comparing them to other wheels of equal weight) seems grossly exaggerated, and probably not even correct. In fact, most wheelsets of comparable lightweight will rather have a lower rim profile to bring the weight down, leading (probably) to even lower rim weight, and therefore leading to lower rotational inertia compared to these wheels (for the same overall wheel weight). OTOH, these wheels will be more aero (for what that is worth at typical modest gravel speeds), which is probably more beneficial than any claim on their exceptional rotational inertia.
When applying teflon tape onto pipe threads, there is only 1 correct direction to apply the tape. Otherwise the tape comes undone when you thread the nut onto the pipe. In a similar fashion, those handlebar grips are wrapped the wrong way; that's why it's coming undone.
Seems like there's a lot of confusion in the comments regarding the performance implications of inertia (rotational or otherwise)- might be worth doing a video on?
The wheelset choice of low inertia vs aerodynamics is skewed for off road wheelsets vs road racing wheelsets. Speeds are generally lower and the larger, knobby tyres give the middle finger to a lot of the aerodynamic rim benefits before the air stream even hits them. For gravel bikes with suspension (or rigid being ridden out of the saddle with bent knees and elbows), Lighter wheels and frames reduce unsprung weight which makes for a smoother and more efficient ride. When you're accelerating suddenly and the frame bends instead of the bike moving forward immediately it is inertia that is stopping you (along with other forms of resistance, though these are not as relevant in that moment). Lowering your system's inertia helps the bike to zing forward- from a "feel perspective" it could be described as feeling stiffer.
As hambini has stated- if you go out on the bike and test wheelsets back to back the difference in feeling is huge. However just because it feels big doesn't mean that it actually is big in terms of watts saved, seconds across the line etc.
In the vast majority of road racing contexts this difference I don't believe this difference is significant, with crit racing and fixed gear street racing (where there is a metabolic cost associated with both accelerating & decelerating both of which happen frequently through big ratios) being notable exceptions.
Truly though the big advantage of lower inertia is for those who aren't racing (against the clock, their strava or others) and who have lower overall power levels. These riders often find accelerating (at the lights, out of turns, on singletrack) and riding up hills the most intense and negative parts of a given ride. Lower inertia and lower weight help to reduce the actual and perceived difficulty of the ride and can help them feel more powerful on the bike- an enjoyable feeling I'm sure we can all relate to.
Get the campy disk, it's amazing, best disk on the market at the moment
I’ve been on the Marvel G35 version of these due to their slightly smaller inner width, they cost me like $700 cad over a year ago and I couldn’t recommend them enough. I’ve put over 6k km on them, with probably 3k of that being actual gravel and they’ve been perfect. Looking to buy a set of 29er rims from them next, I don’t see a reason to look elsewhere.
Also, Galfer discs have been great for me, I go for a lot of rides where a sudden splash or creek crossing can bring your brakes from hot to cold in an instant and they have been good, NTM made in Europe.
Another great reaming by Hamreami!
You should do a video on bearing maintenance from an informed engineering perspective, I find it hard to believe all if these 'bike cleaning products' such as muc off's bike cleaner etc. dont strip grease, i genuinely believe its all marketing. I've found that theres so many conflicting arguments on how to maintain bearings/your bike so it would be interesting to find out your unfilitered perspective.
Bike clearers and degreasers strip grease, just assume they do anyway to be safe. Clean and maintain and sealed bearings should be good.
they tend to dissolve grease so if you use them, they need to have the grease replenished. the other issue is they are full of salt.
@@Hambini they’ll be off the shelves for me then, cheers for the reply. I do wanna know what should be done with bearings though, grease on the outside of them/not (suspension linkage for example) because of the grinding paste effect. I’m guessing maintenance is just some hot water and a sponge. Was literally watching your vid on campag bb’s as you replied, great timing haha.
Going from a deep section budget(ish) rim down to a mavic r sys shallow rim with a 23mm tyre highlights perfectly the benefits to be gained from low rotating mass and acceleration benefits therein. I like the tighter rim.
Me being earrape at the start of every video is what keeps me watching Hambini.
I would think that, at your approx weight, you could run those tires at 3 bar / 40psi and enjoy better ride quality.
I use campagnolo disc rotors with my shimano grx di2 brakes. I’m 90 kg heavy and had no trouble ever (including riding my gravel bike in the alps or up and down the “Großer Arber” = highest Peak of the bavarian/bohemian forest mountain range> resulting in a 18 km/800 hm downhill).
I've been said Galfer disc brakes are the dogs bolloks as far as rotors go, should definitely give them a try, I'm having so many warping problems on my bikes
The are crap, sorry. Measurements on the piss… i use campagnolo rotors without any issues
Swiss stop rotors are the cats meow. 2.3mm thick. But the price is excessive.
@@Nicolas-cm4cc true but they were not available as i needed new rotors
I use Galfer discs on my mtbs, they are excellent, have not had any problems with them, unlike the shimano and sram rotors I used previously.
Regarding warped rotors, I've never warped a straight stainless rotor, even in bike park riding where I've had then turn blue from heat.
Maybe worth trying some non-Shimano rotors that don't do the steel-alu-steel sandwich? They're likely to be less expensive if do do keep having to replace them too.
Untorqued wheel lugs can warp brake rotors on automobiles. Perhaps, brake discs on bikes are so sensitive to proper bolt torque too.
It's a center lock disc, there are no bolts
Low inertia really is a thing; you almost feel like the wheels are pulling you downhill on a descent. The kicker is the front of the bike feels very unsafe in gusty winds.
Thoughts on running these on a road bike with a 28 or 30c road tire?
No issues whatsoever
you had me at "...3 tenths of fuck all, you pedantic bastards!"
Can we have a review of Bitex Hubs and another HUNT reaming!! Thanks.
Hambini have you done berd spokes vs metal spokes? Maybe also carbon, I'm curious power difference at same speed between them on road (rim and hub kept the same)
Very informative, helps in improving riding performance.
I have a set of Elite 50D road wheels. They ride great(!!), but a couple of the bearings in the rear wheel went to crap in 3 months. I weigh about 90 kg. The good news is that they sent me replacement bearings that I received about a week later. So, in my opinion a company you can trust. (But maybe a different hub design compared to the gravel wheels?)
5:49 I say the same thing on a daily basis at work 😄
Had a front wheel of this wheel set totally collapse last year whilst a decent in the forest. Caught a stick in the front wheel and all spokes of the front wheel broke in this accident. I'm never ever going to buy a carbon spoke wheel set for Gravel ever again. Maybe it's a good set for road riding.
Enjoyed as always 😊
60psi will be much too high for anything- even for an indoor wooden track with that setup. You're compromising your rolling resistance and comfort. Try 25psi or look at the Silca tyre pressure calculator.
silca calculator said 28psi. I tried it at 35psi and the tyre came off the rim.
Hello friend, I have a great question. When I turn the cranks I notice that the chainrings have an oscillation, as if they were misaligned or bent. crankset, crowns, and frame are new. Check the crowns and the connecting rod spider on a flat surface and they are correct, there are no waviness or bends. The axle enters smoothly through the bottom bracket, rotates smoothly. I turned the axis of the left crank mounted on the frame and without the crowns, I don't notice that the axis is twisted. Assemble the complete crankset without crowns, and you can see the oscillation movement in the spider. So I don't know what it could be, or if that movement is normal and to what extent. I have seen this in other cranks of different materials and brands and different frames that I have had, but on this occasion I see that the movement is greater.
The only bad thing I found with my 50v Drive is that I can't get the spokes to be parallel when I true them. 😢
Any advice would be appreciated 👍🏼!
Pliers
Idea for rear rotor: can you increase diameter (140 to 160). Idea #2: try a thicker rotor (1.8 or 2.0mm width)
I’m grinning to myself whilst watching this video. Several year ago when everyone seamed to by swapping out their conventional wheels for aero wheels, I did the opposite. I didn’t have a aero bike so one less reason to go aero so I purchased some DT Swiss R21 Dicut wheels at 13000g ish. They changed the ride quality for the better with fast acceleration and lightened up an already light bike. This is particularly beneficial for large riders like me who don’t give a shit about Stava times.
Yeh the aero brigade had better looking faster on the flat bikes, but I had the most fun and my climbing improved overnight.
The moral is, don’t be a 🐑
I've had these wheels for about a year and some of my bearings died after about a thousand miles, the rest have been fine since (9000 miles). There seems to be a lot of variability in their bearing quality.
Did you receive some specially chosen wheels for you review to get the best wheels they had?
So you took very off-roadey tyres, and put basically road pressure in them. That is an *interesting* approach to gravel riding.
yep, it gets ridden more on the road.
In that case, I would suggest less knobby tyres, like Panaracer Gravelking, maybe even the SS version on the rear.
Huh. I use those same rotors on my Roubaix. I put them on a set of Elite Drive 50D wheels, at least partially based on your review.
Anyway, I don’t have any issue with them warping. My typical ride on that bike is about 6000ft of climbing, with screaming descents, often in varying conditions. It’s usually wet during some part of that ride. So I feel like I encounter some similar, possibly more extreme conditions.
After a big braking event from 40mph or so, I can get some brake rub for ten seconds or so. But then it goes away. Is that what you’re referring to? Or more permanent warping?
@hambini I have a customer who walked into my shop complaining that his new wheels (alloy cup and cone generic wheels) were taking way longer to spin down than his old 1970s road bike wheels(13 seconds vs ~300 seconds to stop). I attempted to account for this because the bearings are sealed cup and cone(old most likely unsealed cup and cone), are new vs. old, etc. Needless to say he didn't buy my initial explanations. I've checked the bearings on the new bike and they are preloaded correctly. I've read some stuff on forums saying it's due to weight, and that spindown tests 'don't matter', but some of it is explained in a 'broscience' sort of way. Fundamentally, do (unloaded) spindown tests on wheels matter? If so, or if not, why? It is my guess also that wheel weight might be playing a role too(70's department store bikes are tanks). Thanks!
I guess the wheel bearings are the main factor in how long wheels keep rotating freely. Wheels with a bigger rotational inertia surely have an advantage there, as they start with more stored energy to be dissipated to zero. Though the differences will be rather in percentages and not in whole factors. So bearing smoothness will be decisive. Note that if you check this on the back-wheel, you might also get some influence from the resistance of the freewheel, surely that is also a non-zero effect on how long your (back) wheel will rotate freely. I used to have one particular race bike, when I let the (Mavic) backwheel rotate freely, it started to push the pedals around, showing that the resistance in the freewheel was bigger than the resistance in the BB+chain. I didn't mind though, as when you really need power you push the pedals anyway, and you "lock" the freewheel. So I prefer to have a smooth BB+chain above a smooth freewheel... Most race-bikes seem to have it just the other way around though!? 🤔
They accelerate really well... oké but do they also hold their speed well?
No, they decelerate quickly since deceleration is just negative acceleration. Heavy wheels hold speed well once they are up to speed.
@@asquare9316 you could never write for a cycling magazine....
@@henkdevrjes9640 As if I would ever want to write for a cycling mag. I guess knowing stuff and telling the truth is not what a cycling mag would want in a writer anyway. You're welcome for answering your question.
I have the wheel since 10 months/1400km and the front bearing failed me. the inside of the hub seems dry and the bearings lubed, they sound dry or damaged from the inside however.
2nd this experience. I have a set where the bearings totally shat themselves after a few 100km. The carbon spokes on the rear are also twisting.
Inertia becaame a factor to me when I calculated energy/time loss due to tight road turns around a lake some 30 years ago.
@gerrysecure5874
Can you give some insight in those calculations? What did you find? Were you making a difference in pure mass vs rotational inertia of the wheels?
Firstly, I do love your videos! I'm not sure whats going on though... A low inertia object is an object which is low in mass, yes? It will spin up to speed quickly. (Force, mass, accelleration) These wheels, with these tyres are heavy compaired to most. These will be considered a high inertia wheelset as they take more force to accellerate the higher mass... A set of lighter wheels and tyres would have waaaaayyy lower inertia. On the other hand, a high inertia object is of high mass which takes more force to accellate, once up to speed it may keep spinning for longer, like a heavy fly wheel. I struggle to believe from my riding experience that these wheels spin up to speed easily as you suggested. On top of this there is the massive rolling resistance of nobbly tyres. I guess it all depends what you are comparing it too, a tractor wheel or a road race bike wheel?? If I'm wrong please put me right.
Are you a bit dumb? Of course they're comparing it to other gravel wheels... what else would you compare it to? Jezus xD
When looking specifically at bicycle wheels in a bike, you need to distinguish two types of inertia. 1/ You have the wheel's pure mass ("weight"), which you need to speed up as you increase your riding speed, and 2/ as you start speeding up, obviously the wheel needs to start rotating faster (because you want to roll your wheels on the ground without slipping) , and obviously that also takes up energy. That is linked to the rotational inertia of the wheel (scientifically called moment-of-inertia). And this whole debate here is, what the impact is of this rotational inertia on the (overall) acceleration of a wheel+bike+rider. I haven't met many people that have a natural feeling for what this rotational inertia means in terms of power and energy consumption (no, neither me), but by calculation (or look it up on internet), you can find that for a wheel/loop where all the mass is in the rim, it takes as much energy to make it move, as the energy it takes to rotate it, when it rolls without slipping. The point is, that this energy is only a fraction (1 or 2%) of what it takes to speed-up the mass of rider (+the rest of the bike). So the debate is really about how much of that rotational energy is noticable, and how much difference you can feel if you take a wheel (of same weight) where the rotational inertia is lower (i.e. its mass is not just all located on the rim, but part of the mass is located more centrally). Surely lighter is always better, for both. And surely, a smaller rotational inertia itself must also be "better", but whether just this can effect your biking performance in a somewhat noticeable way, is really where opinions seem to differ.
Love some new Hambini!!
Would you rather go with steel bearings on these wheels if it was an option?
Jan Heine in "The All Road Bicycle Revolution " claims that there is a limit to how light that you can make the rim and not experience handling problems. He noted that makes of 20" folding bikes added mass to the rim. He said that the problem should not show up on 700c bicycles.
I really didn't understand his argument. I am desiring of making my 26" wheels lightweight with light tires. 300g tires for my proposal!
Jan's usage of the term "moment of inertia " was a bit flawed. He equated it with inertia. They are not the same. I have been meaning to write a polite letter to him.😊
My take is that a rider loses the kinetic energy that they built up in the wheels when they apply the brakes. So, we want light rims!
What are you thinking of the zipp303 xplr. I always think deep wheels that are much slimmer than the tire aren‘t really good for aero. You could just make a shallow even lighter one.
If 9 Velo or Elite etc. would make a deepish (45 to 50mm) gravel wheel with a outer width of 40mm i would really buy it. Now i think i have to wait untill the chineses brands hop on this.
An idea how much the sheer deformation of the tyre impacts acceleration? i.e changing the tyre pressure not only affects rolling resistance but also sidewall deformation.
Try these SwissStop Catalyst Race Centre Lock Disc Brake Rotor 160mm
Hello Sir, great Video! I'm in the market for MTB XC racing wheel, so I look at the weight first, then hub quality and ofc price. But what is your recommendation on 6 bolt vs Centerlock? I would go for Galfer discs, thanks!
Hambini, regarding the title of the video, does this mean that we will see marketing departments changing from 'aero' to 'accelleration' gains? This may/should also place emphasis on box section and climbing wheels/weight.
I think for stuff that is at slow speeds like gravel. Emphasis will be on weight and by extension low inertia, it makes you accelerate faster.
@@Hambini Comprehended, thank you Sir.
Mate, do the calcs. How much energy/power do you think it takes to spin up a wheel compared to accelerating the total mass of rider and bike, it's next to nothing. Thats why you can stop a spinning wheel in the air with 1 finger in a second. Try and decellerate the entire mass of rider and bike with one finger. The differences in inertia of different wheelsets are negligable.
Assuming the front and rear wheels weigh in at around 1kg each, if you take off 100g at the edge, you'll end up with 20 percent ISH less inertia.
Let's say it took 20 seconds to accelerate that wheel set before up to speed, it would now take 16 seconds.
There are some approximations in there but it removes the effects of system weight and rider power.
That amount is not insignificant
I don't need to@@Hambini
you done the calc yet?@@Hambini
I'm in a bar with Tyrone and a steel cage. I'm trying to work out how much inertia is needed to move the chain
If you're not going to do it then fine, see below:
75kg rider, 10kg bike, 0-30km/h in 10 seconds.
Rider and bike:
E=(1/2)mv^2
v=8.3m/s
m=85kg
E=2927J
P=E/t
t=10 seconds
P=293W
Wheel:
1kg wheel, 700mm diameter, all mass concentrated on circumferance (worst case)
I=mr^2
m=1kg
r=0.35m
I=0.1225kgm^2
E=(1/2)Iω^2
I=0.1225kgm^2
ω=23.7rad/s
E=34J
P=E/t
P=3.4W
Total power ~ 300W, each wheel is ~ 1% of this assuming all mass is on the circumferance. Difference between two wheelsets is fractions of a percent.
Brilliant vid as usual but am a bit worried about hub internal spares availability for a lot of these new Chinese wheels Brilliant as they are. I know eventually they will probably sort these problems but how are things at the moment with Elite and 9 velo?.
Ha! Here I am working on a 20kg solid aluminum disc wheel for my next hour record attempt 😂
Tri rig omega 1? They make some pretty bold claims. Could you do a review?
Hambini, what do you think about tantan cycling bikes and wheels? They’re also Chinese and really cheap, maybe even too cheap for good standards. Do you plan on doing a review on these in the future? Really love your videos they’re well done (for a 5 yr old)
I think UA-cam might delete anything with “A.l.i. Express”. Maybe they think the comment is intended to sell something. Anyway, love the review.
Enjoyed that, and I can appreciate your arguments for the higher tolerance fields relative to DT Swiss as a base yet can you demonstrate that in a real world case outcome with respect to say reliability and cost over time?
What I'm getting at is something you said, this ain't aerospace, so if it just works, does it need to be 'that good' or is the DT swiss tolerance which is likely on the higher end comparatively to other brands, is that more than enough in a real world case.
Cheers for the content.
Can you please make a video on Buycycle? I am torn about this platform...
How does 9Velo rate for inertia by comparison?
Hey hambini - not a question about this video but would you be open to doing a video on lube / wax and your preferences / experience - keen to hear views on some of the ZFC data
Can you do a show on which wheels go in a straight line? Seems to be fastest way to finish line
Low rotating mass - always a good idea.
Edit: except maybe in a flywheel...
or when trying to cover long distances on flatter terrain
@@asquare9316isn't that only the case if stop starting a lot, or braking for corners?
Zipp 353 rim is 285g. How much is that rim weight? +it is wider at 25mm Inner
I mean 1100USD for a set of these elite drive 50 at 1300 grams vs 4200USD for a set of 353 which are 1255 grams.
1300
We are talking about interia-rim weight not wheel weight
Mr H, I’m a new subscriber to your show so I apologise if my question is not your neck of the woods. Cleaning bike parts in an ultrasonic cleaner - hit or miss? What do you recommend. Many thanks.😊
Now I'm bloody confused. These or 9velo? I need a new set of gravel wheels with microspline freehub.
I am in the same boat here 😂. Either the 9velo GV 2.0 or the Elite Wheels G45 SS, but with an Shimano HG freehub, after all coupons they are about the same price. - Have you decided yet?
EDIT: For 9velo I can also specify brass nipples when ordering, which is a plus, and I think the hub is quite nice, but the print on the rim was nicer in the previous GV version. On the Elite Wheels the finish of the rims seem to be quite nice and they come with ceramic bearings. Weight is also about the same...hmm
Nah, I haven't yet decided. SO much choice. I want to avoid hookless rims like the plague is the only thing I do know.
@@DonnieX6
@@shannonparker7404 Dang, was hoping you already pulled the trigger on something! Yeah, so much choice... and definitley no hookless!
FYI, I am also looking at the following: Winspace Lun Grapid, Nextie build with the GX NXT40GX rims and DT350SL, Farsports C3, and Light Bicycle A35 rims with DT Swiss 350.
Did you find anything else interesting that would fit?
The thing that is of utmost for me is local support. I've recently been burnt by poor support from a large offshore wheel manufacturer. I'm now leaning towards getting some wheels locally built with local bike shop support. Probably DT350 or 240 straightpull hubs, CX ray spokes and I'm hearing good things about Nextie NXT45AGX rims.... And the surprising thing is they will be cheaper than a Big Brand name!@@DonnieX6
Was in the same boat. These have free shipping and with discount codes the ss version are a few hundred dollars cheaper than 9velo once you add their shipping
are the decals removable?
No, they're under the clear coat
@@Runningonmymindblog You can see on the video they are on not under
@@anothervisionofthings I have a set, they're 100% under the clear coat and not removable
what do you think of the 5 and 6 spoke all carbon gravel wheels?
asking for a friend….
I've had Aerospoke 5 spoke wheels for over 20 years now on my touring bike, they are wonderful and strong and look sensational. Great for long distances on flatter terrain.
Carbon spokes on rough terrain? Even on poorly maintained paved roads they're too harsh.
Well low inertia means they might spin up faster but they also slow down faster...
Great vid Hambini. I have a set of Elite wheels with high engagement hubs. What grease do you recommend for this type of pawl hub? There seems to be quite a bit of drag
Nlgi 2
Thanks!
Also make sure not to overgrease. 95% of everyone puts in way too much grease. If you put in just the smallest amount, and think it's too little, don't add more cause you probably added too much and didn't even realize it.
Do you put the grease on the pawls them self's or in the hub part? Suppose it doesn't make much difference?
26 is dead, aero is dead, 27,5 is dead blablabla. Cycling industry wants your money.
What is the difference between low inertia and low weight when applied to wheels? Not a lot of freedom to shift weight around.
The mass of a wheel has two forms of inertia to ovecome when speeding it up as you accelerate: rotational inertia (moment of inertia) to make the wheel rotate (where the distance of its distributed mass from the center plays a big role), and its pure mass to accelerate it linearly. If we assume that all the mass ("weight") of the wheel is situated in the outer rim, and assuming you accelerate your bike while you roll your wheel over the road without slipping, than the energy that you will need to put in the wheel to make it rotate, is exactly the same as the energy you will need to make it move linearly (=your riding speed). The very interesting (and -at least for me- somewhat surprising) part is that these two movements (rotation and translation) take up exactly the same amount of energy in the case of (such) a bike wheel. If you manage to make such wheel lighter, you will have advantage on both these energy consumers (as your wheels absorb/store rotational energy and kinetic energy as you accelerate). For most people this rotational energy isn't very quantifiable intuitively (though, we do know that it doesn't take much energy to stop a rotating wheel), but accepting (or re-calculate if you want...) it is of the same order (well, theoretically identical) as the energy of a moving object of the same weight being thrown to you, this may give you somewhat a clue. Now, if you compare these two (equal) energy absorbers, and compare that to the combined weight of your body and the rest of your bike, which also need to accelerate at the same time at the same rate as your wheels, of course those will be the main energy absorbers of whatever your output power is on your pedals. As mentioned in other comments, you will spend less than 2% of your power to make your wheels rotate, and 98% of your power output to accelerate linearly (your body + bike including its wheels). Now if you manage to take some of the weight off the wheels, you'll be already better off, *both* for rotational and linear movement energy consumption/storage. If you make your wheels only half as heavy (say 1kg vs 2kg), you'll be able to spend about 99% (iso 98%) of your power input to accelerate linearly, and only 1% needs to go into the rotation. So you will accelerate 1% faster. If it would normally take you 10sec to get upto your desired speed, with wheels half as light, it will take you 9.9sec! Yes, 1% is small, but it could make the difference between winning and loosing. Now, assume we manage to build a wheel with the same initial weight, but we manage to shift half of that weight to the middle around the axis. There, weight doesn't contribute to the uptake of rotational energy. This wheel has lower moment of inertia, only half as much, so it takes up only half as much energy to spin it up. Compared to our initial bike, the only thing that will change is that the energy that will get stored in the rotation of the wheel while accelerating is only half of what we used to spend first. So we can use this "saved" energy to accelerate a little faster. Though, we still need to spend the same energy to accelerate the body+bike+wheels linearly. So you would be able to spend something between 98 and 99% of your power to accelerate linearly. So you would be able to accelerate to the same speed in about 9.9x seconds. Right, that could also make you win a race. Bottomline , overall weight of a wheel is more import than trying to optimize the moment of inertia (for the same wheel weight). If you have the choice between a wheel with light weight and a wheel with "improved" moment of inertia, take the lighter wheel. And to close this topic, unless you are riding rather slow (gravel?), doing lots of climbing and/or lots of of accelerating/decelerating, choose the most aero wheel first, even when there is a (modest) penalty in weight and/or moment of inertia.
@@wouterdobbelaereWhen I slam the brake while the bicycle is up on the repair stand, the whole bicycle and stand shake as the kinetic rotational energy is transferred to the bicycle. That tells me the magnitude of stored rotational energy.
@@Fetherko Exactly! And it is the same amount of energy that this wheel would have if someone was throwing it at you with the same speed (albeit without rotation), at least when the rim carries all the weight. The more the weight is centralized on or close to the axis, the less the rotational energy becomes for the same rotational speed (compared to linear inertia/energy). So, yes, surely, the rotational energy isn't zero, so it makes sense to try to reduce it further. Just that we are mainly debating here at what level of difference in total energy consumption we are looking here. Is it gains, marginal gains or non-measurable gains? The jury is still out...
How about discuss the ackchual benefits of low weight vs aero for gravel riding?
As % of total mass 200g is insignificant, so we are discussing the benefit of snappy acceleration? But fast accel means fast decel too?
Compare with aero where wins are real wattage all day.
Is point of gravel maybe that speeds are lower so aero doesnt matter?
Or are you just yanking our chains?
If you don't get above 20kph. Why bother with aero
I was hoping they had pawl, centerlock, carbon spoked 29er xc wheelset, but no.
700C Is Same as a 29
@@yesmate78 But do not fit on Boost 148/110 spacing
35-60 psi. 60 psi it is. I like your philosophy.