I believe the entire reason there was/is a push for wider tires is because the industry was trying to solve the tubeless setup punctures and getting the sealant to work as well as it does for mtb. The industry makes more money selling tubeless technology than simply using an inner tube. I prefer a narrower tire for road use because I am old school in my belief that a road bike simply must have skinny tires. I've tried 28mm tires on my road bike and for me it doesn't feel like a road bike anymore. I'm sticking to the 26mm tires and rims that are 19mm to 21mm internal and TPU tubes, this offers me the feel I am happy with no matter how much it beats me up.
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Thanks for digging into this. As is usual with the Internet, the "Wider is faster and more comfortable" rule was over time stripped of all context and turned into a primitive mantra that people are just endlessly repeating in every discussion... Funny thing is that actually SILCA THEMSELVES have an article on their blog where they are scientifically measuring and explaining why narrower tires at equal pressure are less harsh. Because what people forget about that "wider means lower RR" rule is that is says "provided pressure is equal". But then you don't get good comfort. Yes, offroad wider tires are more comfortable AND faster when you lower pressures but as the surface gets better and better the situation changes and the understanding of this seems to be missing from the discussion these days. Everyone is just blabbering "fit the widest your frame can handle" ad nauseam... I recently put 36mm Strada Biancas on one of my wheelsets and I'm constantly amazed at how supple, comfortable and fast these tires are in dry conditions. I'm a MTBiker converted to a gravelist, I've never ridden anything that narrow in my life. I was expecting to suffer but somehow on everything except loose chunkier gravel I feel better. I'm sure it's predominantly caused by the Challenge casing and not the width but still, bumps, holes and such just seem to "sting" less because the small tire is "done with them" sooner if you know what I mean... also I like the agility of the narrow tire and the fact that line choice is easier.
Thanks for sharing your experience about 36mm tires! Would you share, what is your weight, your bike's weight, internal wheel (rim) width and PSI of your tires? I'm curious because 36 to 38mm tires sound way better to me as a die-hard road cyclist who is interested in light gravel. Thank you!
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@@dustinsanders2175 Gladly! I'm 74 kg, I'm riding a Ti gravel that has 9.9 kg catalogue weight but with all gear it's like 11. I have those Biancas on fairly generic 21 mm IW alloy wheels. For pressure I'm running whatever Silca calculator recommends for a given scenario. I sometimes combine surface categories in the sense that I put Gravel cat 2 pressure in front and Bad Asphalt pressure in rear or both pressures midway between Gravel Cat 2 and 3 or something like that. But I never wildly deviate from Silca recs. Also I still have this wheelset on latex tubes, not yet TL.
16 днів тому
@@dustinsanders2175 Not sure about US but for Central Europe 35 - 36 mm seems like the minimum sensible width for road use. Yes, people who ride on reasonably maintained state roads or other busy types of roads may utilize narrower rubber but I try to stick to less busy backroads, asphalted FSRs etc., hate having to deal with drivers. My brother is a pure roadie and has his Specialized Roubaix maxed out to 35 mm slicks and he's happy with it, certainly not missing out on performance.
one other factor to consider is that when running tubeless it doesn't seem to seal anything larger than a pinprick well when over 50psi. For most gravel/larger road tires where you're likely running under that anyways it's no issue then but for a narrower tire like a 28 that can result in some loss of pressure before it manages to seal a small cut. Great video as always! I thoroughly enjoy seeing every new upload of yours
I suspect the tubeless debate has not run the course (bad pun) completely yet. Already, there's a large swing away from them. I just don't get it for distance cycling. I'm mechanically inclined, and carry a frugal tool kit, and so everyone expects me to fix their flats for them. "Tubeless"? They're on their own.
@@overbikedrandonneuringVery nice! I run the same setup - 30mm GP 5000 STR tires (tubeless) with 25mm internal width wheels. I hover around 65 to 68 kilos with a bike of about 7 kilos. 48 PSI (3.3 bar) for both of my tires, I've found, gives wonderful comfort and no discernable decrease in speed. As a big benefit, I haven't had a single puncture since switching to this configuration in 2024.
I've had great comfort on 25mm (27mm when measured) tires at lower pressures but have issues with pinchflats when I get too excited and rough with my bike. I've now ridden 23, 25, 32, 38, 42 and 50mm tires and so far 32-38 seems like a good sweet spot for me, I can get enough tire drop for good comfort without risking pinchflats on those. 42 and bigger at low pressures felt slow and a bit wallowy in corners, and at higher pressures felt very bouncy, where they would bounce over bumps rather than absorb them. I do have to add the 42 and 50mm tires had a slightly heavier build than the skinnier ones which will undoubtedly have a negative effect on how they feel.
I always tended to run lower pressures (80-85psi rear, less front) on my old ('03) bike with 15mm rims. With 25mm Conti GP4000s, I may have pinched ONCE over 5 years. Switched to Pirelli P Zeros last year and they pinch flatted 3 times in a couple months running 80-ish psi, so had to pump to 90+ after that. Fast forward to now: New bike with 30mm front, 32mm rear (Schwalbe Pro 1), bought mainly to ride on bigger tires. Started at 65 rear, 60 front and the ride was brutal! Settled in on 48 rear 43 front and ride is better (if still somewhat firm) but without a single flat so far. Anyway, excellent analysis and thanks for doing this. I'll eagerly continue to monitor your future findings.
The more TPI the suppler/softer the tire, so need more pressure. I too run 15mm rims and 25mm tires and pump them to roughly 80-90 psi. The push for wider tires is precisely because of tubeless and need for lower operating pressures to seal well, and with lower pressure you need wider tire obviously to keep the same rolling resistance and energy loss and rigidity.
@@heksogen4788 On your first point, the 4000s had 330 tpi; the Pirelli P Zero Road has 127, so that wouldn't explain why the Pirellis tended to pinch more often with the same pressure -- must be something else. (For the record, I'm 154 lbs/70kg.) As for the trend towards wider tires, it started when research thoroughly debunked the myth that they had higher rolling resistance at when run at the lower pressures that gave a better ride, not the desire to push everyone to tubeless (which I have no desire to switch to, personally). The only argument against width seems to be aero related, not a factor with me as I don't regularly roll along at 25+ mph.
Thanks! As a not-so-tough cyclist, it's really important to me. It's nice to be able to share my testing and findings too. Hope we can all ride maximally fast and comfy
One variable that is really important for my mental endurance is grip confidence. In the summer in the UK, 28mm with redshift suspension is perfect - comfortable, grippy enough, and rolls fast. But in winter on damp, cold, dirty roads I want 35mm for grip. Even though it's more effort, it's significantly offset by having grip confidence. If I ride long distance with 28mm tyre on winter roads, I'm totally knackered at the end, just because I spend so much time anxious about grip on little lanes.
Absolutely. That is a topic I plan to discuss when I can finally compare efficiency and comfort of different sized tires. The wider ones will always have more grip at the same comfort level due to that comfort equalizing at a lower PSI.
[One variable that is really important for my mental endurance is grip confidence.] This is a very good point, especially for those of us already massively, and in my case, irreparably, injured from going down (My accident, after the thousands of kms I do in the country, was mid-town here in Toronto, with a slab of concrete 30mm 'discontinuous' which I glanced against. I got railed. All four major muscle tendons were torn putting my arm out to break the fall. I will almost inevitably win the claim against the city, I've done a massive amount of legal research which my solicitors love, but the point of how incredibly vulnerable we are is expressed in faith in those tires being able to handle the vectored stresses applied to them. My choice of 4 Seasons was based on that. You trade a performance edge for safety. In the event, unless you're racing, that trade-off is superfluous, especially in wet weather when you'd be crazy to push a performance tire to the limit anyway. Btw: I declined a reverse total shoulder replacement. After three months, I got back on the bike, once I realized I could find my balance again. And it's been the best therapy possible to make the best of what's left of the shoulder. I can't lift my bike over a fence, but I can cycle 100kms to get there.
Norcal Cycling did a video a little while back comparing just the efficiency of different tire widths, although it's not clear whether tires were inflated to their most efficient pressure in each width. Found that 32 mm was the most efficient.
Yeah, that was one of the inspirations for this video and line of experimentation actually. I edited out a little chat about it to keep this video more on topic. The NorCal video was filmed to suggest they set pressures based on nominal width (32c, 34c) and didn't adjust for measured width after measurements were taken. The large tires which overperformed were 31 and 33mm, while the 28 was true to size. The larger tires would have about 3 PSI less than the measured width would dictate when using the Silca calculator. It was also mentioned that the course was a bit rough. When combined with the Silca calculator aggressively lowering pressures as tires get larger, it could be that the narrow tire was overinflated for conditions. When GCN went to the Silverston rolling resistance drum, the Silca recommendations had the narrow tire roll more efficiently than the wider tires. On a drum test, this is also consistent with the narrow tire being overinflated or wider tires being underinflated since on a drum more pressure equals more efficiency. I worry these two tests are assessing the Silca Calculator rather than the tires, but the results are being communicated as comparing if they are comparing the tires.
I toured all over the Western states when younger and always used the narrowest tires I could find in 27 inch and pumped them up, usually, to 110 to 115 pounds of pressure. I can't recall them being uncomfortable to ride on just quicker and more responsive. My favorites were Speciazed 1" tires. Max pressure was 95, but I always went 15 to 20 lbs over on those clinchers. Don't think they make them anymore. I still use 27" tires rather than 700C. Only 8mm bigger but just that little more easier on rolling.
[ I can't recall them being uncomfortable to ride on just quicker and more responsive. ] Errr...I used to ride the 18s (sometime marketed as 19s, Specialized, also 27" at the time, until I finally went 700c) and pumped them up to 120 psi. I'm lucky they didn't kill me. Or more correctly, killed myself. Even 25c get rutted sometimes on uneven asphalt, or in rain channels on gravel. Your idealized memory does not serve you well. I also used to cycle distance in sandals. Phhhh......
@stephensaines7100 I am sorry if my comment disturbed. I was merely sharing information. Perhaps it was my good saddle, an Avoset Touring II leather saddle, that kept me comfortable. Also, no longer made. My bike was an '86 Miyata 610, I still have, slowly and extensively changed from stock to be lighter. The steel metal frame was quite absorbent of jolts and bumps. Three main tubes are chrome moly. The others mild steel. Got over 250,000 miles on her. I seldom tour these days as I'm quite fragile at 77y.o. Wishing you lots of great rides in your adventures. Yours always, Johann Kuester.
Nice work - especially explaining the drop concept thanks. Nb Rim width also factors into using lower pressures especially on gravel. Wider rims 'square' the tire improving cornering and stability whereas narrower gives a 'light bulb' shape that feels a bit smoother and cushier.
A decade or so ago, Mavic published some research on their A319/A379 rims, which were intended for backpackers, off-road, and distance touring. They were a fair bit wider than your typical road rim at the time, and Mavic made a point of how they catered to wider road tires and more and how the sidewalls were held more optimally with the wider 'stance' offered by the rims. Just checking now, Mavic still have their promo page up on them.
68 still riding with a reverse left shoulder replacement ya my days of riding on 21 mm tires our done so 700-30 as 65 psi now really saves the shoulder pain
Whoa! I signed the releases and 6 pages of documents to get my right shoulder done after a cycling spill 2 and a half years ago. Details elsewhere in this forum, but I *declined* the op, as a last question to the Ortho: "What if I have another accident and damage that shoulder again". One of Canada's most noted and accomplished shoulder surgeons replied: "Then you're $&()&^#". It's an 'operation of last resort'. I went conservative, and used the rage to fight my way back to riding tall. Saw the doc for check-up 10 days ago. One of the questions I asked was: "If I'd have the op, would I have got back as much function as I now have?" After I did a number of RoM moves, the answer was: "You've gone beyond a reverse total replacement". He had been on my case from right after the accident to "Get back on the bike. No pain-killers, no sling, no excuses.". Sometimes, if you can channel it, rage is a good thing. And of course, cycling dissipates it and builds large amounts of muscle (what's still there) in the arms and torso as well as the legs. I'm 75, btw.
Thank you for the informative video. I have one request though. Please include tyre pressures in Bar next time along with PSI. I know this may sound nitpicky, but i really have trouble understanding Imperial units of measurement, outside of the metric system. Otherwise keep up the great work, i love how you back up your content with measured data and still make it easy to understand for most!
Thanks! Sorry about the lack of BAR. I've lived in a metric country for 10 years and have transitioned to all the other measurements, but not pressure haha. I'll work on that for future videos.
yes i can agree ..with adding that depending on road surface and amount of unexpected pothole..if you run tubes setting too low a psi in a narrow tire could land a pinch flat. But for good roads all fine.
Fascinating, and very much in line with my intuitive realisations. I've subscribed, this line of discussion is so welcome, I wish to see what other findings you are able to present. I'll wait until then to discuss some nuances that also bear on what is optimal. What I can state from experience, and this wasn't the original intention, is that I'm using a 32c (Conti 4 Seasons) on the rear, and the same on the front, except 25c. The Contis are wearing so well that I haven't the cause to use my 28c spare (which I carry at all times, along with tubes, and tools, I'm old-school), and I'm starting wonder if the 25c is proving to be the best choice? *For the front*! I'm very happy with the 32c on the rear, but if the need arises to replace it, I might just use the 28c spare. The frame is a Seventies 531 DB Reynolds, renovated by Argos Racing in the Eighties, and I bought it used for a song in Taunton twenty-five years ago. The most comfortable ride I've ever had. For me anyway, mid-Seventies, and still doing distance treks (up to 100km in a day, trail and weather permitting) what appears optimal for the rear is not the same criteria as the front. I'm looking forward to your next post on this.
Thank you for the kind words. I think as long as the pressures are set well, you should be able to get great performance from any reasonably sized tire. Bigger tires certainly offer a greater range of possible comfort. I am most curious to see how closely a tire's comfort and efficiency are linked. That will determine if a wider rear tire should be the go-to strategy.
Very interesting speach. Thanks for it. For my road bike I feel the sweet spot is 25mm front and 28 rear (cannot go and would not go further anyway). I put same pressure in both, and I feel fine this way.
I am not sure what your point is wrt SILCA. Their calculator is optimized for rolling resistance and nothing else, in particular not comfort. I do believe the give the best results in that respect over all calculators, given the amount of testing and the apparently semi-solid protocol they’ve put in place to calibrate their algorithm. Silverstone bike engineering hub seems to give similar results.
My end goal is to be able to optimize comfort and speed, which includes accounting for tire size. The Silca calculator claims to optimize for the speed, which would be really helpful in that pursuit. It's just been accepted at face value though and doesn't help us choose tire size. Their pressure curve has a lot of implications on that goal if it really gives us peak efficiency, but is in conflict with other plausible theories. Testing the comfort provided by their recommendations is a step towards making better overall choices.
@@stevenr5149 Hi Steven, thanks for watching. There are elements of comfort that are subjective, but vibration can be measured. Vibration measurements are extensively used in automotive industry to assess auto comfort, driveability, and ride quality. It is also measured for worker health and safety in many fields. In this video and others, I measure vibration at the handlebar or the saddle rails in meters per second squared. Data is collected over 200 times per second. I hope through these measurements, we can better understand the relationship between tires size, pressure, comfort, and eventually efficiency.
@@overbikedrandonneuringYour data collection is fantastic. Sample sizes are huge over the test parameters. My take away is if I am to continue to use Silca as my go to for tire pressures then wider is indeed better for comfort at the Silca recommended pressures. Thanks for all the efforts putting this together.
I M cycling for 55 years mow and still doing 250 km/week. Mainly on my 80s steel bikes. I always buy the cheapest 700 x 25 at the max pressure and happy. And i dont mind of im fast or slow, im outside, smell the nature and hear the birds and im happy. And i have average 2 punctures/year what tells me its tome to replace the tyres
I think it's important to prioritize speed over all else, since the faster you go the sooner you're done, and no bike setup will ever be as comfortable as a post ride beer on the couch!!
That is how I actually felt when I burnt out as a Roadie. I road a Cervelo with max 25mm tire clearance.😵💫😵💫 I had to relax AFTER a ride. Now I ride on clouds on my Crust with Rene Herse 42mm & 50mm tires on pressure below 40lbs. Now I don't pay attention to speed & cycling IS my fun & relaxation😎😊
The Silca tire pressure calculator probably prioritizes rolling resistance over comfort. Impedance from road surface decreases as as tire pressure goes down to a point. The point being where tire deflection increases rolling resistance more than decreased impedance decreases the rolling resistance. The Silca pressure calculator attempts to set a pressure where these two lines on a graph converge giving the least rolling resistance. Comfort is a side effect of this. Speed is the priority here but comfort does contribute to speed!
That is their claim, but we are asked to take it at face value. with very little evidence of specific methodology or results have been presented. Cycling media has just accepted everything and used it to compare tires of different widths as though it presents each width in their best light. I want to dig deeper and hopefully uncover if these claims are accurate, how much comfort and how much efficiency can we expect at these ideal pressures at different widths.
The point of this video eludes me. Everyone not living under a rock knows that tire pressure matters for all sizes. Yes, the 28mm tires on my vintage steel road bike feel reasonably comfortable when set to their optimum comfort drop. And the 35 mm tires of my steel touring bike are also comfortable when dropped to their best comfort drop. However, the overall comfort factor of the 35 is noticeably higher and handling much improved. Comparing over inflated vs under inflated tires is idiotic.
The point is to understand how width affects comfort and how comfort can be predicted. I suspect how cycling media (mainstream and alt-cycling) present these ideas may be flawed or incomplete. The outcome of 26mm tires at 70 PSI feeling about the same as my usual 33mm tires at 57PSI was a huge surprise and points towards the need for more exploration.
@@overbikedrandonneuringWhy compare your 33 mm at 57 when they should have been at 49 just like as shown in your chart. I think the comment above was stating same thing. Data should be done at optimized settings for each width which I feel the Silca is a good representation.
@@mitchhorton9178 Hi Mitch, for the past year or so I've been running 57 PSI in my 33mm tires, which results in about the same comfort as the 70PSI 26mm. That was unplanned but a very interesting finding. As mentioned in the graphic near the beginning of the video, I used to Silca calculator to set intentionally soft pressures, which results from changing the terrain setting. Your comment actually points to my end goal, of developing a deeper understanding of comfort and efficiency across widths. This video is only part of that exploration. Thanks for watching!
I do not mind riding a Michelin Lithium 23mm on my forewheel on short sporty rides. The tyre/rim combo is more aero, lighter and......yes cheaper. With relative low pressure its comfy enough too and gives a relative wide contact patch for safety. They measure 24mm on my rims and its all just fine. Back wheel other story. ps. I still have to find normal priced latex inner tubes.
Thanks! I'm very curious what the data will say. I may need to procure a dual sided power meter to approach anything close to precise efficiency testing. If data points to different widths having comfort and efficiency directly linked (tire drop/hoop stress) I'll probably drop to 28c tires at low pressures since I'm heavy. If the wider tires offer the same efficiency and lots more comfort (Silca) I'll likely move to 32-34c and get new wheels in the 34-38mm width range.
I just ride my boomer cross bike or boomer mountain bike if i want more comfort. Or I stick on the cane creek ee-silk that I got as an experiment. I find with large tires I still like to run medium high pressures since in the corners or standing I hate the wallowy feel. Always appreciate testing and experiments like that. I do find ultimately for larger impacts the larger tires are better, even at higher pressure since there is just more rubber and air soaking up the impact it seems to be a bounce rather then a hammer hit.
Love me some micro suspension. One of the things I dislike about doing these vibration tests is removing my Vecnum stem or Redshift seatpost. I expected better hard hit performance from larger tires, but there was little evidence of that when comparing the highest 5% of acceleration readings within each test run relative to overall averages. Quite the surprise! Big tires still offer a certain confidence.
Great video! This is the kind of nit-picky testing I've wanted for these questions. I don't know how to test it, but I've been wondering if the size of the contact patch of the tire relative to the size of the road surface imperfection could create a difference in comfort between tire sizes. I suspect that if you increase the contact patch while keeping the hoop stress constant, you'd see a smaller vibration while rolling over some kind of small imperfection. It might explain the convergence of vibration magnitudes across the different tire sizes as the hoop stress increases, since higher hoop stress would also decrease the contact patch for a given tire size. (The effect shouldn't matter if the road surface imperfection is larger than the contact patch of the tire.)
That's an interesting idea explaining the comfort drift as hoop stress increases. I've not fully abandoned the hoop stress hypothesis and will be testing it in the future when I do the 'efficiency-at-comfort' tests. Thanks!
I’m planning on running a GP 5000 allseason 35C next season on my new steel rando bike tubeless, one other consider for me is it seams most of my local routes have some gravel on the routes even if at a few KM it might be alittle to wide but I already spent the money and got the tires so here goes. I do think for these types of distance 200 to 400K for me comfort is #1
You'll love that setup! Especially in the rain, those tires should be excellent. Most small gravel sectors can be handled quite well with a 35c tire too. Which bike did you get?
@ it’s a Bilenky Tourlight Columbus steel frame bike. He is a small frame builder here in the USA. I’m super excited, I got to pick everything from the 40/26 crankset to the wheels and 10 speed Campy drive train with a 13/29 cassette so I should have some nice low gears for the hills. It will be here Tuesday can’t wait I’m gonna do a UA-cam vid on her if you want I will send you the link I. A comment on one of your videos.
@@irondistance4313 Wow, that looks like a lovely build! Such an interesting choice in gearing too, and it sounds wonderful for randonneuring. I'll subscribe to your channel so I don't miss out.
@ thanks I hope to have the video up in two weeks weather is crap here in the Pacific NW USA I want to at least give a first ride testimony so I can say something about it. As for the gearing I think this Overbiked Randoneuring guy had something to say about Chris Froome granny gears😂🔥🔥🔥.
Please make tests with top end cotton tires in 25 mm, like Veloflex or Challenge, you will have at least 5-10% more comfort at same pressure compared to Schwalbe
Honestly, I would be quite curious about that. I'll add it to my to-do list depending on how the comfort vs. efficiency vs. width testing shakes out. That test may take quite a while to develop and complete though. Thanks for the idea!
Hi, I liked your video. Very useful information, thank you. How about puncture exposure? I'm comparatively knew to all this (1 year experience on a road bike) and I was doing this (putting much less pressure than recommended) unknowingly, just because I felt better on the bumpy roads we have here in Bulgaria, until a knowledgeable friend told me that I was doing something wrong because in this way I increased risk of puncture. Is it true at all? (I'm running RideNow TPUs inside Continental GP5000 tires on a 25f/28r mm Canyon Aeroad setup, if it's of any importance)
There is some hearsay about wider tires puncturing less, but the biggest concern with narrow tires at low pressures is pinch flats or rim damage. I was worried I would pinch flat doing the 70 PSI test on the 26mm tire, but luckily didn't.
@@overbikedrandonneuring Well, 70 psi isn't low in my world, that's what Silca recommends in my case too, anyway 25/28 mm tires, 86/74 psi, respectfully. I was talking more about 55-60, this way I was trying to avoid the whole pain in the ass of handling and maintaining sealant in my tires. My friend's idea was the lower the pressure level, the laxer and therefore more susceptible to penetration by a thorn, nail, glass shard, etc. the tire material becomes.
The opposite has been argued before, that a softer carcass will better deform around potential penetrating objects. I don't believe it is a meaningful difference either way, and that it comes down more to rubber thickness and protective plies of fabric in the tire. Potholes and curbs may induce pinch flats with 55-60 PSI in your 25mm tire though. The 28 might support 60 PSI with less risk of a pinch flat. Rider weight and the prevelance of potholes/curbs impact those considerations.
Silca's 32mm pressure is quite a bit lower than the low hoop stress pressure, while for the 26 they are about equal. Do you know why the 26 should not go lower in pressure? In your chart going from 72 to 70 PSI has more difference in comfort as going from 80 to 72 on the 26mm. So maybe the range of the 26mm tire is larger. Also, would inner tube choice effect the results in any way?
Because Silca biases narrow tire for higher hoop stress and wider tires for lower, the 32.5mm tire got a very low pressure recommendation. I set my Silca calculator inputs to target the roughest parts of my test loop, so the results were generally really soft. The low hoop stress condition was set such that I would be unlikely to damage the 26mm tire on the course. The gap between 70 and 72 PSI is likely just test noise. Inner tubes affect efficiency for sure, but wall thickness of a pressure vessel also impacts the calculation for hoop stress. By keeping inner tubes the same, I can better control variables.
Narrow tires require high pressures to avoid pinch flats when using tubes. There is really no way around that. When using tubeless setup, then you can start exploring lower pressures. This was not an option in the past.
The pro's have pretty much gone to wider tires, especially on the descents for better traction. Unlikely we will go back to narrow tires, wide tires offer better traction, superior efficiency, with the correct air pressure better comfort.
I've heard rumors that there is sponsor pressure to use wider tires than might be most efficient. That's part of my goal though, to discover how significant these differences are to better optimize tire choice for long distance cycling. Grip in cornering and braking is a big part of that, and my testing here confirms that wider tires will always have better grip at the same comfort level. I edited that out section from the script to better focus on just comfort, but it will be a talking point once comfort and efficiency between tire widths is more clear.
Hey, could someone give me advice on PSI? I weigh 80kg and ride a 10kg road bike with 35mm panaracer x1+ tires on 21 internal and 23 ext wight scribe race wheels with TPU inner tubes. I ride on poor pavement, which PSI should i be riding on?
Start with your highest pressure and ride over your average surfaces(and the poor pavement on a 5-10minute loop). Let 5lb out and go again, and again, etc. It is a fun project. When it gets too low for me, I feel it when cornering. At 30lbs, I'm on rails. At 20lbs I'm still on rails, but they are too squishy in high speed cornering. (I ride 42-55mm tires) 60 kgs(with ME, bike, & gear😳) You'll probably need a bit more pressure than me 😉
I am old and could care less about wide tires. I think 2 inch max width is plenty for any bicycle use. Besides being heavier with greater rotational inertia and rolling resistance, fat tires IMO get flat more often as well. The only suspension one needs for road use is maybe a cantilever armature for the seat which itself is sprung. The only reason anyone would need 3" or 4 " tires is to ride on sand or snow. I personally avoid off road riding in the first place, so for me fat tires are completely pointless. I could imagine maybe 2" for e-bikes since they have a built-in heavier load, but much of the excess weight on those bikes is also unnecessary, as they use insanely heavy steel multi-tubed and frankly decorative fabrications.
The test is not good. You have to do the same test again with a Power Meter and run those test at the same AVG power, then we will get a better test and you have to also add the avg speed to the data.
@benoittheminerandgamer I kept the same cadence and gear selection through the test. Each lap was 4:26 +/- 3 seconds. Average speed was always 23.3 kph +/- .2kph. In this case, equalizing power would skew results and make them incomparable. Future tests will include power when assessing efficiency.
Interesting! All over the place brands and UA-cam are sticking to the simplified statement that bigger is more comfortable without loosing speed. But the details on comfort are lacking in nearly all those channels or salespitches. One reason I can see a conspiracy: we have to buy disc brakes bikes. I like disc brakes, but don’t want to spend the money when I don’t see the need. They need to make me see a need for it, so they tell me my life will become more comfortable when I change to a new bike… Crazier conspiracies have been true.
Better get that tinfoil hat at the ready, I haven’t seen evidence yet that disproves their use! But seriously, you have an interesting point of view in this video.
I ride 2.2 tires on my drop bar mtn bike. Will never go back to a road bike. Going a little faster just not important to me. I ride gravel and trails and as little pavement as possible.
I sometimes miss my old custom titanium monstercross bike. 2.4" WTB tires, Lauf fork, frankenstein drivetrain. Where I live now, road riding is really accessible and gravel/trails are not. Even moving from a vanilla gravel bike to a road bike for these conditions is quite nice. Sounds you are Overbiking for your conditions though, which is great.
As a 90kg rider who has destroyed rims on potholes before, this was very much a consideration. I refer to it with 'minimum safe pressures' and highlight that the 26mm tire did not suffer pinch flats during my test. I also limited the lowest 26mm pressure to avoid that problem. However, my original script did include 'as long as pinch flats and rim damage can be avoided' around the 12 minute mark, but I failed to include that in my recording since I was trying to avoid reading directly from the script. I'll be sure to highlight this in the followup video to this test.
@overbikedrandonneuring Thanks mate, I'm glad you considered it, I am 191cm and ≈100kg. I have changed to 32mm tires and love being able to drop the pressure to 60psi. It seems most cycling gear is pushed towards 60kg riders
I'm bike shopping right now and this test got me rethinking everything. Y'all got any hints on where to find a tire drop calculator?
I believe the entire reason there was/is a push for wider tires is because the industry was trying to solve the tubeless setup punctures and getting the sealant to work as well as it does for mtb. The industry makes more money selling tubeless technology than simply using an inner tube. I prefer a narrower tire for road use because I am old school in my belief that a road bike simply must have skinny tires. I've tried 28mm tires on my road bike and for me it doesn't feel like a road bike anymore. I'm sticking to the 26mm tires and rims that are 19mm to 21mm internal and TPU tubes, this offers me the feel I am happy with no matter how much it beats me up.
Thanks for digging into this. As is usual with the Internet, the "Wider is faster and more comfortable" rule was over time stripped of all context and turned into a primitive mantra that people are just endlessly repeating in every discussion... Funny thing is that actually SILCA THEMSELVES have an article on their blog where they are scientifically measuring and explaining why narrower tires at equal pressure are less harsh. Because what people forget about that "wider means lower RR" rule is that is says "provided pressure is equal". But then you don't get good comfort. Yes, offroad wider tires are more comfortable AND faster when you lower pressures but as the surface gets better and better the situation changes and the understanding of this seems to be missing from the discussion these days. Everyone is just blabbering "fit the widest your frame can handle" ad nauseam...
I recently put 36mm Strada Biancas on one of my wheelsets and I'm constantly amazed at how supple, comfortable and fast these tires are in dry conditions. I'm a MTBiker converted to a gravelist, I've never ridden anything that narrow in my life. I was expecting to suffer but somehow on everything except loose chunkier gravel I feel better. I'm sure it's predominantly caused by the Challenge casing and not the width but still, bumps, holes and such just seem to "sting" less because the small tire is "done with them" sooner if you know what I mean... also I like the agility of the narrow tire and the fact that line choice is easier.
Thanks for sharing your experience about 36mm tires! Would you share, what is your weight, your bike's weight, internal wheel (rim) width and PSI of your tires? I'm curious because 36 to 38mm tires sound way better to me as a die-hard road cyclist who is interested in light gravel. Thank you!
@@dustinsanders2175 Gladly!
I'm 74 kg, I'm riding a Ti gravel that has 9.9 kg catalogue weight but with all gear it's like 11. I have those Biancas on fairly generic 21 mm IW alloy wheels. For pressure I'm running whatever Silca calculator recommends for a given scenario. I sometimes combine surface categories in the sense that I put Gravel cat 2 pressure in front and Bad Asphalt pressure in rear or both pressures midway between Gravel Cat 2 and 3 or something like that. But I never wildly deviate from Silca recs. Also I still have this wheelset on latex tubes, not yet TL.
@@dustinsanders2175 Not sure about US but for Central Europe 35 - 36 mm seems like the minimum sensible width for road use. Yes, people who ride on reasonably maintained state roads or other busy types of roads may utilize narrower rubber but I try to stick to less busy backroads, asphalted FSRs etc., hate having to deal with drivers.
My brother is a pure roadie and has his Specialized Roubaix maxed out to 35 mm slicks and he's happy with it, certainly not missing out on performance.
Just transitioned to 32mm tires from 28mm for my winter riding. Really comfortable and no noticeable speed loss
one other factor to consider is that when running tubeless it doesn't seem to seal anything larger than a pinprick well when over 50psi. For most gravel/larger road tires where you're likely running under that anyways it's no issue then but for a narrower tire like a 28 that can result in some loss of pressure before it manages to seal a small cut.
Great video as always! I thoroughly enjoy seeing every new upload of yours
For sure! I've found 65PSI has been the point where my tubeless sealant fails to function. My current setup is under 60PSI though, so no issues.
I suspect the tubeless debate has not run the course (bad pun) completely yet. Already, there's a large swing away from them. I just don't get it for distance cycling. I'm mechanically inclined, and carry a frugal tool kit, and so everyone expects me to fix their flats for them. "Tubeless"? They're on their own.
@@overbikedrandonneuringhi, for your setup under 60psi, may I ask what is the tire width?
@@johnicology I currently run 30c GP5000 STR or Schwalbe Pro One TLE, which inflate to 33mm on rims with 25mm internal width. I currently use 57PSI.
@@overbikedrandonneuringVery nice! I run the same setup - 30mm GP 5000 STR tires (tubeless) with 25mm internal width wheels. I hover around 65 to 68 kilos with a bike of about 7 kilos. 48 PSI (3.3 bar) for both of my tires, I've found, gives wonderful comfort and no discernable decrease in speed. As a big benefit, I haven't had a single puncture since switching to this configuration in 2024.
I've had great comfort on 25mm (27mm when measured) tires at lower pressures but have issues with pinchflats when I get too excited and rough with my bike.
I've now ridden 23, 25, 32, 38, 42 and 50mm tires and so far 32-38 seems like a good sweet spot for me, I can get enough tire drop for good comfort without risking pinchflats on those.
42 and bigger at low pressures felt slow and a bit wallowy in corners, and at higher pressures felt very bouncy, where they would bounce over bumps rather than absorb them. I do have to add the 42 and 50mm tires had a slightly heavier build than the skinnier ones which will undoubtedly have a negative effect on how they feel.
I always tended to run lower pressures (80-85psi rear, less front) on my old ('03) bike with 15mm rims. With 25mm Conti GP4000s, I may have pinched ONCE over 5 years. Switched to Pirelli P Zeros last year and they pinch flatted 3 times in a couple months running 80-ish psi, so had to pump to 90+ after that.
Fast forward to now: New bike with 30mm front, 32mm rear (Schwalbe Pro 1), bought mainly to ride on bigger tires. Started at 65 rear, 60 front and the ride was brutal! Settled in on 48 rear 43 front and ride is better (if still somewhat firm) but without a single flat so far. Anyway, excellent analysis and thanks for doing this. I'll eagerly continue to monitor your future findings.
The more TPI the suppler/softer the tire, so need more pressure. I too run 15mm rims and 25mm tires and pump them to roughly 80-90 psi. The push for wider tires is precisely because of tubeless and need for lower operating pressures to seal well, and with lower pressure you need wider tire obviously to keep the same rolling resistance and energy loss and rigidity.
@@heksogen4788 On your first point, the 4000s had 330 tpi; the Pirelli P Zero Road has 127, so that wouldn't explain why the Pirellis tended to pinch more often with the same pressure -- must be something else. (For the record, I'm 154 lbs/70kg.) As for the trend towards wider tires, it started when research thoroughly debunked the myth that they had higher rolling resistance at when run at the lower pressures that gave a better ride, not the desire to push everyone to tubeless (which I have no desire to switch to, personally). The only argument against width seems to be aero related, not a factor with me as I don't regularly roll along at 25+ mph.
With this vibration test setup you are becoming the de facto source for evaluating real-world comfort properties of cycling parts and kit!
Thanks! As a not-so-tough cyclist, it's really important to me. It's nice to be able to share my testing and findings too. Hope we can all ride maximally fast and comfy
One variable that is really important for my mental endurance is grip confidence. In the summer in the UK, 28mm with redshift suspension is perfect - comfortable, grippy enough, and rolls fast. But in winter on damp, cold, dirty roads I want 35mm for grip. Even though it's more effort, it's significantly offset by having grip confidence. If I ride long distance with 28mm tyre on winter roads, I'm totally knackered at the end, just because I spend so much time anxious about grip on little lanes.
Absolutely. That is a topic I plan to discuss when I can finally compare efficiency and comfort of different sized tires. The wider ones will always have more grip at the same comfort level due to that comfort equalizing at a lower PSI.
[One variable that is really important for my mental endurance is grip confidence.] This is a very good point, especially for those of us already massively, and in my case, irreparably, injured from going down (My accident, after the thousands of kms I do in the country, was mid-town here in Toronto, with a slab of concrete 30mm 'discontinuous' which I glanced against. I got railed. All four major muscle tendons were torn putting my arm out to break the fall. I will almost inevitably win the claim against the city, I've done a massive amount of legal research which my solicitors love, but the point of how incredibly vulnerable we are is expressed in faith in those tires being able to handle the vectored stresses applied to them. My choice of 4 Seasons was based on that. You trade a performance edge for safety. In the event, unless you're racing, that trade-off is superfluous, especially in wet weather when you'd be crazy to push a performance tire to the limit anyway.
Btw: I declined a reverse total shoulder replacement. After three months, I got back on the bike, once I realized I could find my balance again. And it's been the best therapy possible to make the best of what's left of the shoulder. I can't lift my bike over a fence, but I can cycle 100kms to get there.
Norcal Cycling did a video a little while back comparing just the efficiency of different tire widths, although it's not clear whether tires were inflated to their most efficient pressure in each width. Found that 32 mm was the most efficient.
Yeah, that was one of the inspirations for this video and line of experimentation actually. I edited out a little chat about it to keep this video more on topic. The NorCal video was filmed to suggest they set pressures based on nominal width (32c, 34c) and didn't adjust for measured width after measurements were taken. The large tires which overperformed were 31 and 33mm, while the 28 was true to size. The larger tires would have about 3 PSI less than the measured width would dictate when using the Silca calculator. It was also mentioned that the course was a bit rough. When combined with the Silca calculator aggressively lowering pressures as tires get larger, it could be that the narrow tire was overinflated for conditions. When GCN went to the Silverston rolling resistance drum, the Silca recommendations had the narrow tire roll more efficiently than the wider tires. On a drum test, this is also consistent with the narrow tire being overinflated or wider tires being underinflated since on a drum more pressure equals more efficiency. I worry these two tests are assessing the Silca Calculator rather than the tires, but the results are being communicated as comparing if they are comparing the tires.
I toured all over the Western states when younger and always used the narrowest tires I could find in 27 inch and pumped them up, usually, to 110 to 115 pounds of pressure. I can't recall them being uncomfortable to ride on just quicker and more responsive. My favorites were Speciazed 1" tires. Max pressure was 95, but I always went 15 to 20 lbs over on those clinchers. Don't think they make them anymore. I still use 27" tires rather than 700C. Only 8mm bigger but just that little more easier on rolling.
[ I can't recall them being uncomfortable to ride on just quicker and more responsive. ] Errr...I used to ride the 18s (sometime marketed as 19s, Specialized, also 27" at the time, until I finally went 700c) and pumped them up to 120 psi. I'm lucky they didn't kill me. Or more correctly, killed myself. Even 25c get rutted sometimes on uneven asphalt, or in rain channels on gravel.
Your idealized memory does not serve you well. I also used to cycle distance in sandals. Phhhh......
@stephensaines7100 I am sorry if my comment disturbed. I was merely sharing information. Perhaps it was my good saddle, an Avoset Touring II leather saddle, that kept me comfortable. Also, no longer made. My bike was an '86 Miyata 610, I still have, slowly and extensively changed from stock to be lighter. The steel metal frame was quite absorbent of jolts and bumps. Three main tubes are chrome moly. The others mild steel. Got over 250,000 miles on her. I seldom tour these days as I'm quite fragile at 77y.o. Wishing you lots of great rides in your adventures. Yours always, Johann Kuester.
Yep I’m still on 23c on the front and 25c on the rear 😊
I'm the same but otherwise 23c at the rear 25c on the front at 80psi.
Nice work - especially explaining the drop concept thanks. Nb Rim width also factors into using lower pressures especially on gravel. Wider rims 'square' the tire improving cornering and stability whereas narrower gives a 'light bulb' shape that feels a bit smoother and cushier.
A decade or so ago, Mavic published some research on their A319/A379 rims, which were intended for backpackers, off-road, and distance touring. They were a fair bit wider than your typical road rim at the time, and Mavic made a point of how they catered to wider road tires and more and how the sidewalls were held more optimally with the wider 'stance' offered by the rims.
Just checking now, Mavic still have their promo page up on them.
68 still riding with a reverse left shoulder replacement ya my days of riding on 21 mm tires our done so 700-30 as 65 psi now really saves the shoulder pain
Whoa! I signed the releases and 6 pages of documents to get my right shoulder done after a cycling spill 2 and a half years ago. Details elsewhere in this forum, but I *declined* the op, as a last question to the Ortho: "What if I have another accident and damage that shoulder again". One of Canada's most noted and accomplished shoulder surgeons replied: "Then you're $&()&^#". It's an 'operation of last resort'. I went conservative, and used the rage to fight my way back to riding tall. Saw the doc for check-up 10 days ago. One of the questions I asked was: "If I'd have the op, would I have got back as much function as I now have?" After I did a number of RoM moves, the answer was: "You've gone beyond a reverse total replacement". He had been on my case from right after the accident to "Get back on the bike. No pain-killers, no sling, no excuses.". Sometimes, if you can channel it, rage is a good thing. And of course, cycling dissipates it and builds large amounts of muscle (what's still there) in the arms and torso as well as the legs.
I'm 75, btw.
Thank you for the informative video. I have one request though. Please include tyre pressures in Bar next time along with PSI. I know this may sound nitpicky, but i really have trouble understanding Imperial units of measurement, outside of the metric system.
Otherwise keep up the great work, i love how you back up your content with measured data and still make it easy to understand for most!
Thanks! Sorry about the lack of BAR. I've lived in a metric country for 10 years and have transitioned to all the other measurements, but not pressure haha. I'll work on that for future videos.
yes i can agree ..with adding that depending on road surface and amount of unexpected pothole..if you run tubes setting too low a psi in a narrow tire could land a pinch flat. But for good roads all fine.
Fascinating, and very much in line with my intuitive realisations. I've subscribed, this line of discussion is so welcome, I wish to see what other findings you are able to present. I'll wait until then to discuss some nuances that also bear on what is optimal.
What I can state from experience, and this wasn't the original intention, is that I'm using a 32c (Conti 4 Seasons) on the rear, and the same on the front, except 25c. The Contis are wearing so well that I haven't the cause to use my 28c spare (which I carry at all times, along with tubes, and tools, I'm old-school), and I'm starting wonder if the 25c is proving to be the best choice? *For the front*! I'm very happy with the 32c on the rear, but if the need arises to replace it, I might just use the 28c spare. The frame is a Seventies 531 DB Reynolds, renovated by Argos Racing in the Eighties, and I bought it used for a song in Taunton twenty-five years ago. The most comfortable ride I've ever had.
For me anyway, mid-Seventies, and still doing distance treks (up to 100km in a day, trail and weather permitting) what appears optimal for the rear is not the same criteria as the front.
I'm looking forward to your next post on this.
Thank you for the kind words. I think as long as the pressures are set well, you should be able to get great performance from any reasonably sized tire. Bigger tires certainly offer a greater range of possible comfort. I am most curious to see how closely a tire's comfort and efficiency are linked. That will determine if a wider rear tire should be the go-to strategy.
Very interesting speach. Thanks for it. For my road bike I feel the sweet spot is 25mm front and 28 rear (cannot go and would not go further anyway). I put same pressure in both, and I feel fine this way.
I am not sure what your point is wrt SILCA. Their calculator is optimized for rolling resistance and nothing else, in particular not comfort. I do believe the give the best results in that respect over all calculators, given the amount of testing and the apparently semi-solid protocol they’ve put in place to calibrate their algorithm.
Silverstone bike engineering hub seems to give similar results.
tends to be a good guideline for comfort too as any lower is often a risk of being too low to protect the rim and bead
My end goal is to be able to optimize comfort and speed, which includes accounting for tire size. The Silca calculator claims to optimize for the speed, which would be really helpful in that pursuit. It's just been accepted at face value though and doesn't help us choose tire size. Their pressure curve has a lot of implications on that goal if it really gives us peak efficiency, but is in conflict with other plausible theories. Testing the comfort provided by their recommendations is a step towards making better overall choices.
@@stevenr5149 Hi Steven, thanks for watching. There are elements of comfort that are subjective, but vibration can be measured. Vibration measurements are extensively used in automotive industry to assess auto comfort, driveability, and ride quality. It is also measured for worker health and safety in many fields. In this video and others, I measure vibration at the handlebar or the saddle rails in meters per second squared. Data is collected over 200 times per second. I hope through these measurements, we can better understand the relationship between tires size, pressure, comfort, and eventually efficiency.
@@overbikedrandonneuringYour data collection is fantastic. Sample sizes are huge over the test parameters. My take away is if I am to continue to use Silca as my go to for tire pressures then wider is indeed better for comfort at the Silca recommended pressures. Thanks for all the efforts putting this together.
I
M cycling for 55 years mow and still doing 250 km/week. Mainly on my 80s steel bikes.
I always buy the cheapest 700 x 25 at the max pressure and happy. And i dont mind of im fast or slow, im outside, smell the nature and hear the birds and im happy. And i have average 2 punctures/year what tells me its tome to replace the tyres
I rode 23mm clinchers at 95psi the other day , they felt soft , i felt lumps & bumps all the more compared to a 28mm tubeless at 70psi
My data suggests the 28mm tire should be a bit smoother. For me, running 23 tires is a one way ticket to pinch flats haha.
I think it's important to prioritize speed over all else, since the faster you go the sooner you're done, and no bike setup will ever be as comfortable as a post ride beer on the couch!!
Brought to its logical conclusion... ride a shorter distance, or perhaps stay on the couch altogether? I don't get it.
I hope that’s sarcasm 🤣
That is how I actually felt when I burnt out as a Roadie. I road a Cervelo with max 25mm tire clearance.😵💫😵💫 I had to relax AFTER a ride. Now I ride on clouds on my Crust with Rene Herse 42mm & 50mm tires on pressure below 40lbs. Now I don't pay attention to speed & cycling IS my fun & relaxation😎😊
And thus the genesis of the e-biker.
Why ride at all?
Good quality test!
The Silca tire pressure calculator probably prioritizes rolling resistance over comfort. Impedance from road surface decreases as as tire pressure goes down to a point. The point being where tire deflection increases rolling resistance more than decreased impedance decreases the rolling resistance. The Silca pressure calculator attempts to set a pressure where these two lines on a graph converge giving the least rolling resistance. Comfort is a side effect of this. Speed is the priority here but comfort does contribute to speed!
That is their claim, but we are asked to take it at face value. with very little evidence of specific methodology or results have been presented. Cycling media has just accepted everything and used it to compare tires of different widths as though it presents each width in their best light. I want to dig deeper and hopefully uncover if these claims are accurate, how much comfort and how much efficiency can we expect at these ideal pressures at different widths.
The point of this video eludes me. Everyone not living under a rock knows that tire pressure matters for all sizes. Yes, the 28mm tires on my vintage steel road bike feel reasonably comfortable when set to their optimum comfort drop. And the 35 mm tires of my steel touring bike are also comfortable when dropped to their best comfort drop. However, the overall comfort factor of the 35 is noticeably higher and handling much improved. Comparing over inflated vs under inflated tires is idiotic.
The point is to understand how width affects comfort and how comfort can be predicted. I suspect how cycling media (mainstream and alt-cycling) present these ideas may be flawed or incomplete. The outcome of 26mm tires at 70 PSI feeling about the same as my usual 33mm tires at 57PSI was a huge surprise and points towards the need for more exploration.
@@overbikedrandonneuringWhy compare your 33 mm at 57 when they should have been at 49 just like as shown in your chart. I think the comment above was stating same thing. Data should be done at optimized settings for each width which I feel the Silca is a good representation.
@@mitchhorton9178 Hi Mitch, for the past year or so I've been running 57 PSI in my 33mm tires, which results in about the same comfort as the 70PSI 26mm. That was unplanned but a very interesting finding. As mentioned in the graphic near the beginning of the video, I used to Silca calculator to set intentionally soft pressures, which results from changing the terrain setting. Your comment actually points to my end goal, of developing a deeper understanding of comfort and efficiency across widths. This video is only part of that exploration. Thanks for watching!
Simple answer - Yes!! Next question.......
I do not mind riding a Michelin Lithium 23mm on my forewheel on short sporty rides.
The tyre/rim combo is more aero, lighter and......yes cheaper.
With relative low pressure its comfy enough too and gives a relative wide contact patch
for safety. They measure 24mm on my rims and its all just fine. Back wheel other story.
ps. I still have to find normal priced latex inner tubes.
interesting. Looking forward to you telling us what tyre width and pressure you choose for your bike(s) and i will be very happy to imitate
Thanks! I'm very curious what the data will say. I may need to procure a dual sided power meter to approach anything close to precise efficiency testing. If data points to different widths having comfort and efficiency directly linked (tire drop/hoop stress) I'll probably drop to 28c tires at low pressures since I'm heavy. If the wider tires offer the same efficiency and lots more comfort (Silca) I'll likely move to 32-34c and get new wheels in the 34-38mm width range.
12:03 In a Swiss Side's calculator recommendations are 5.5+ bar setup. But this is 80+ psi, and this is huge for a long course. nope?
@sonofthenorth it's 10-15 psi less than Silca calculator recommendations for my weight and "worn pavement/ some cracks".
I just ride my boomer cross bike or boomer mountain bike if i want more comfort. Or I stick on the cane creek ee-silk that I got as an experiment. I find with large tires I still like to run medium high pressures since in the corners or standing I hate the wallowy feel. Always appreciate testing and experiments like that. I do find ultimately for larger impacts the larger tires are better, even at higher pressure since there is just more rubber and air soaking up the impact it seems to be a bounce rather then a hammer hit.
Love me some micro suspension. One of the things I dislike about doing these vibration tests is removing my Vecnum stem or Redshift seatpost.
I expected better hard hit performance from larger tires, but there was little evidence of that when comparing the highest 5% of acceleration readings within each test run relative to overall averages. Quite the surprise! Big tires still offer a certain confidence.
Great video! This is the kind of nit-picky testing I've wanted for these questions. I don't know how to test it, but I've been wondering if the size of the contact patch of the tire relative to the size of the road surface imperfection could create a difference in comfort between tire sizes. I suspect that if you increase the contact patch while keeping the hoop stress constant, you'd see a smaller vibration while rolling over some kind of small imperfection. It might explain the convergence of vibration magnitudes across the different tire sizes as the hoop stress increases, since higher hoop stress would also decrease the contact patch for a given tire size. (The effect shouldn't matter if the road surface imperfection is larger than the contact patch of the tire.)
That's an interesting idea explaining the comfort drift as hoop stress increases. I've not fully abandoned the hoop stress hypothesis and will be testing it in the future when I do the 'efficiency-at-comfort' tests. Thanks!
I’m planning on running a GP 5000 allseason 35C next season on my new steel rando bike tubeless, one other consider for me is it seams most of my local routes have some gravel on the routes even if at a few KM it might be alittle to wide but I already spent the money and got the tires so here goes. I do think for these types of distance 200 to 400K for me comfort is #1
You'll love that setup! Especially in the rain, those tires should be excellent. Most small gravel sectors can be handled quite well with a 35c tire too. Which bike did you get?
@ it’s a Bilenky Tourlight Columbus steel frame bike. He is a small frame builder here in the USA. I’m super excited, I got to pick everything from the 40/26 crankset to the wheels and 10 speed Campy drive train with a 13/29 cassette so I should have some nice low gears for the hills. It will be here Tuesday can’t wait I’m gonna do a UA-cam vid on her if you want I will send you the link I. A comment on one of your videos.
@@irondistance4313 Wow, that looks like a lovely build! Such an interesting choice in gearing too, and it sounds wonderful for randonneuring. I'll subscribe to your channel so I don't miss out.
@ thanks I hope to have the video up in two weeks weather is crap here in the Pacific NW USA I want to at least give a first ride testimony so I can say something about it. As for the gearing I think this Overbiked Randoneuring guy had something to say about Chris Froome granny gears😂🔥🔥🔥.
Please make tests with top end cotton tires in 25 mm, like Veloflex or Challenge, you will have at least 5-10% more comfort at same pressure compared to Schwalbe
Honestly, I would be quite curious about that. I'll add it to my to-do list depending on how the comfort vs. efficiency vs. width testing shakes out. That test may take quite a while to develop and complete though. Thanks for the idea!
Its interesting how moto gp also has balloon tires that squirm inder acceleration also being light and fast!
Very interesting!
Hi, I liked your video. Very useful information, thank you. How about puncture exposure? I'm comparatively knew to all this (1 year experience on a road bike) and I was doing this (putting much less pressure than recommended) unknowingly, just because I felt better on the bumpy roads we have here in Bulgaria, until a knowledgeable friend told me that I was doing something wrong because in this way I increased risk of puncture. Is it true at all? (I'm running RideNow TPUs inside Continental GP5000 tires on a 25f/28r mm Canyon Aeroad setup, if it's of any importance)
There is some hearsay about wider tires puncturing less, but the biggest concern with narrow tires at low pressures is pinch flats or rim damage. I was worried I would pinch flat doing the 70 PSI test on the 26mm tire, but luckily didn't.
@@overbikedrandonneuring
Well, 70 psi isn't low in my world, that's what Silca recommends in my case too, anyway 25/28 mm tires, 86/74 psi, respectfully.
I was talking more about 55-60, this way I was trying to avoid the whole pain in the ass of handling and maintaining sealant in my tires.
My friend's idea was the lower the pressure level, the laxer and therefore more susceptible to penetration by a thorn, nail, glass shard, etc. the tire material becomes.
The opposite has been argued before, that a softer carcass will better deform around potential penetrating objects. I don't believe it is a meaningful difference either way, and that it comes down more to rubber thickness and protective plies of fabric in the tire.
Potholes and curbs may induce pinch flats with 55-60 PSI in your 25mm tire though. The 28 might support 60 PSI with less risk of a pinch flat. Rider weight and the prevelance of potholes/curbs impact those considerations.
Maybe I missed it, or should know, but are you running tubes or tubeless for all widths tested?
@matthewsponseller tpu tubes for the front tires being tested. Thanks for watching!
Silca's 32mm pressure is quite a bit lower than the low hoop stress pressure, while for the 26 they are about equal. Do you know why the 26 should not go lower in pressure? In your chart going from 72 to 70 PSI has more difference in comfort as going from 80 to 72 on the 26mm. So maybe the range of the 26mm tire is larger.
Also, would inner tube choice effect the results in any way?
Because Silca biases narrow tire for higher hoop stress and wider tires for lower, the 32.5mm tire got a very low pressure recommendation. I set my Silca calculator inputs to target the roughest parts of my test loop, so the results were generally really soft. The low hoop stress condition was set such that I would be unlikely to damage the 26mm tire on the course. The gap between 70 and 72 PSI is likely just test noise. Inner tubes affect efficiency for sure, but wall thickness of a pressure vessel also impacts the calculation for hoop stress. By keeping inner tubes the same, I can better control variables.
Irrelevant, but once I spotted this I couldn't ignore. Is something tracking your pupils (10:08-10:10) or can you shoot lasers from your eyeballs?
Reflection of the ring light. It shaves 10 years off my face. I'll have to look into laser eyes though, it mght help deal with car traffic.
Narrow tires require high pressures to avoid pinch flats when using tubes. There is really no way around that. When using tubeless setup, then you can start exploring lower pressures. This was not an option in the past.
YES
The pro's have pretty much gone to wider tires, especially on the descents for better traction. Unlikely we will go back to narrow tires, wide tires offer better traction, superior efficiency, with the correct air pressure better comfort.
I've heard rumors that there is sponsor pressure to use wider tires than might be most efficient. That's part of my goal though, to discover how significant these differences are to better optimize tire choice for long distance cycling. Grip in cornering and braking is a big part of that, and my testing here confirms that wider tires will always have better grip at the same comfort level. I edited that out section from the script to better focus on just comfort, but it will be a talking point once comfort and efficiency between tire widths is more clear.
Hey, could someone give me advice on PSI? I weigh 80kg and ride a 10kg road bike with 35mm panaracer x1+ tires on 21 internal and 23 ext wight scribe race wheels with TPU inner tubes. I ride on poor pavement, which PSI should i be riding on?
Start with your highest pressure and ride over your average surfaces(and the poor pavement on a 5-10minute loop). Let 5lb out and go again, and again, etc. It is a fun project. When it gets too low for me, I feel it when cornering. At 30lbs, I'm on rails. At 20lbs I'm still on rails, but they are too squishy in high speed cornering. (I ride 42-55mm tires)
60 kgs(with ME, bike, & gear😳) You'll probably need a bit more pressure than me 😉
@stevenr5149 thank you for your advice 🙏
I am old and could care less about wide tires. I think 2 inch max width is plenty for any bicycle use. Besides being heavier with greater rotational inertia and rolling resistance, fat tires IMO get flat more often as well. The only suspension one needs for road use is maybe a cantilever armature for the seat which itself is sprung. The only reason anyone would need 3" or 4 " tires is to ride on sand or snow. I personally avoid off road riding in the first place, so for me fat tires are completely pointless. I could imagine maybe 2" for e-bikes since they have a built-in heavier load, but much of the excess weight on those bikes is also unnecessary, as they use insanely heavy steel multi-tubed and frankly decorative fabrications.
I guess I’m old school I ride 28s 100 psi I tried 32s at 70 like riding in sand 😂
The test is not good. You have to do the same test again with a Power Meter and run those test at the same AVG power, then we will get a better test and you have to also add the avg speed to the data.
@benoittheminerandgamer I kept the same cadence and gear selection through the test. Each lap was 4:26 +/- 3 seconds. Average speed was always 23.3 kph +/- .2kph. In this case, equalizing power would skew results and make them incomparable. Future tests will include power when assessing efficiency.
Interesting! All over the place brands and UA-cam are sticking to the simplified statement that bigger is more comfortable without loosing speed. But the details on comfort are lacking in nearly all those channels or salespitches.
One reason I can see a conspiracy: we have to buy disc brakes bikes. I like disc brakes, but don’t want to spend the money when I don’t see the need. They need to make me see a need for it, so they tell me my life will become more comfortable when I change to a new bike… Crazier conspiracies have been true.
Good points all around. I will wear a tinfoil hat if I uncover suspicious results.
Better get that tinfoil hat at the ready, I haven’t seen evidence yet that disproves their use!
But seriously, you have an interesting point of view in this video.
I ride 2.2 tires on my drop bar mtn bike. Will never go back to a road bike. Going a little faster just not important to me. I ride gravel and trails and as little pavement as possible.
I sometimes miss my old custom titanium monstercross bike. 2.4" WTB tires, Lauf fork, frankenstein drivetrain. Where I live now, road riding is really accessible and gravel/trails are not. Even moving from a vanilla gravel bike to a road bike for these conditions is quite nice. Sounds you are Overbiking for your conditions though, which is great.
yes.
Everyone can now move on.
You are fogetting that heavier riders can't run smaller tires at lower pressure, due to pinch flat risks
As a 90kg rider who has destroyed rims on potholes before, this was very much a consideration. I refer to it with 'minimum safe pressures' and highlight that the 26mm tire did not suffer pinch flats during my test. I also limited the lowest 26mm pressure to avoid that problem. However, my original script did include 'as long as pinch flats and rim damage can be avoided' around the 12 minute mark, but I failed to include that in my recording since I was trying to avoid reading directly from the script. I'll be sure to highlight this in the followup video to this test.
@overbikedrandonneuring Thanks mate, I'm glad you considered it, I am 191cm and ≈100kg. I have changed to 32mm tires and love being able to drop the pressure to 60psi. It seems most cycling gear is pushed towards 60kg riders
yes
I just think riders now are a bunch of wimps. They want over size tires and low pressure for more comfortable rides 😂
Can confirm, I am not a tough guy.
No one ever seems to care about the WEIGHT of wider tires. What happened to every micro-gram counts?