The Great Wheel Debate: 650b vs 700c Part 3: A Practical Field Test

Hello everyone and welcome back to part three of the great wheel debate. It’s been a while since we first looked at the differences between narrow and wide road tires.
In this video we are going to pick up where we left off with an experiment comparing 650bx48 with 700c x 25 mm tires by riding two 5 minute long timed sections of road. The purpose of this test is to determine if there is magnitude of difference in speed between these two wheel and tires sizes in a real world test. The math we performed in part one and two of this series suggests that the wider tires may actually roll faster, at least in the absence of wind resistance. I haven’t been able to test this theory until now. Over the past few years since first making this series I had a custom bike built that will accommodate wide 650b x 48mm tires.
There is a common perception that narrow 700c tires at higher air pressure will roll faster than a wider tire set at a lower air pressure, but is this true? Some folks such as myself have long wanted to know how close our perception is to reality. Jan Heine from Bicycle quarterly has been discussing this topic for many years. He has performed tests that have shown wider tires rolling faster than narrow tires. For anyone who has ridden on both sized tires will find it is easy to dismiss his results because riding on narrow tires very often feels faster. With that, today we are going to perform our own pseudo scientific test to see if we can make any meaningful conclusions.

[@p.g.reitsma7245]

Greetings Henry. I was just riding my 650b Velo Toussaint Routier today, with the Pacenti Pari-Moto 47's. With all the crap going on in the world lately, I'm just happy to ride alone on an Alberta back road and think deeply about life, family and friends, and how cycling makes life better. Thanks always for your videos and your testing 😘

[@dougcohenmiller]

My takeaway is that as a non competitive bicyclist, there is no benefit to 700c skinny tires. Very thoughtful video, as always. Keep it up.

[@dougcohenmiller]

Click Bait I’ve not gotten a flat in years. Knock on wood.

[@randallsmith7885]

@@dougcohenmiller I have heard that a 650b tire which is inflated at typically lower pressures than 700c narrow tires can be very flat resistant.

[@trek520rider2]

@@dougcohenmiller get some Rene Herse (formerly Compass) tires and you'll fix that. I know whereof I speak.

[@stevemillerster]

I had the same take away, @doug.

[@jasonhearne1174]

Your test was actually fairly scientific. Adding cadence would have added more support to fairness but generally your HR control was on point. All the science I've read continues to tell me fat tyres are faster right up until the point where aerodynamics matter - circa 40km/h - and the speed differential will drop the closure you approach aerodynamic impact. The missing test for me here is what happens when you run a fat 700c tyre - GK38 or Rene Herse 38 - over a 700 X 25 Gatorskin. 650 has benefits but if you can get those benefits on a larger rim then surely the benefit increases.

[@hyano8216]

Never seen except this video that logical explanation using the actual data. Pre much appreciated for your efforts. Also your pronunciation is pre much easy and very kind for foreigner.

[@matthieumoreau5125]

A long time MTB rider, I am looking into getting my first gravel bike and these videos are definitely helpful in my search/eduction on the subject. Thanks Henry!

[@Henrywildeberry]

Cheers!

[@Peter-tc3ep]

Using a power meter I discovered, 700x28-30 are decently faster then 650x47-50. I personally like 700x38-40 for comfort with a minimum amount of extra power required. I used my Open UP for my testing, this bike is disc braked and I have a 650 and 700 DT Swiss GR 1600 wheelset for both. Using a heart rate monitor is not an accurate way to test verse a power meter. Using 240W’s for all tires for a 15 mile loop road, the 700x28 tires ran 48 seconds faster, the 700x38 tires were 32 seconds faster then the 650x48. I used Vittoria Corsa G2 for 28, Rene Herse Steilacoom 38 and Rene Herse Juniper Ridge 48. There is a reason in gravel races riders all use 700x35-40. There is a point were you start to use more power but don’t realize since wider tires provide more comfort on broken pavement but when it comes to hills you notice how much more power is required to climb. And how much rolling resistance slows you down after a hill. Using a heavier wheelset plus only a heart rate monitor both makes your test inaccurate. Plus did one wheelset have better hubs then the other and is your bike optimized to use either size wheels. I badly wanted wider 650 wheels to be faster because they are more comfortable but even testing the 38’s verse the 48’s on a 9.6 mile gravel/dirt trail with 411 feet of vertical change the 38’s still 29 seconds faster using 250w’s of power for both. On short bursts of 1.5 mile loops trying to get the same time, the 48 wheels required about 20w’s more power. I wouldn’t bring my 28 slick road tires anywhere near the trail they flat, only tubeless tires that can withstand rocks. I’ve played with slick tires verse patterned tires for power usage, found that tire material matters just as much as pattern. Something like the Schwalbe g ones look fast but were actually slower rolling then the Rene Herse Steilacoom, both on and off pavement. This was a shock, the Maxxis Ramblers were also quicker then the panaracer GravelKing SK’s, the Rene Herse Barlow Pass were much faster then the GravelKing flats. So a more supple or tacky rubber was faster then a hard rubber. The hard rubbers were a bit more durable on harsher gravel roadways. The softer rubber tires also tended to weigh 100g less then hard rubber tires which also helped. I use this info because I race gravel in New England for fun, Ted King’s home town NH race last two years and 3 other races in Vermont and Massachusetts. And there is definitely a reason racers are using 700x35-40 sized tires, they are unfortunately faster or use less power, from talking to other racers including Ted King, 42 seems to be the point of no return. And that seems to be the max most racers will even if think of using in a race no matter how muddy the conditions. Again heart rate is not power used, since your body’s comfort can have an impact on your heart rate. You should use a power monitor.

[@Henrywildeberry]

Hi Peter, Thanks for sharing your test results. Did I read your test description correctly, the 650b tires you tested were a knobby 650b x 48mm wide (Juniper Ridge) and compared those to a slick Vitoria Corsa 28? It's interesting to see how fast a knobby tire actually rolls on pavement! A difference of 48 seconds over a 15 mile course, that's pretty amazing. Not to take anything away from your testing as it is very interesting, but there are couple of things to keep in mind. A power meter would be a more objective way to perform this test, especially if the rider using it can pedal in a very controlled manner, and the power data itself was accurate. Most power meter data is very scattered as I'm sure you know. In order to read the data there is quite a bit of averaging necessary to smooth out the erratic peaks and valleys. Most power meters take a sample at the crank and since power is not uniform over the complete pedal cycle, each pedal stroke is averaged again. Some power meters like Stages for example only sample from one side of the crank, and double that number to compensate for the other side. A power meter is also only as accurate as the strain gauges and data acquisition systems they used to construct it. Most use a temperature compensating strain gauge to eliminate the variations caused by outside temperate changes, but there is still a certain amount of inaccuracy with all consumer grade power meters. Unfortunately, due to the size and weight of these bicycle power meters they are not very accurate for testing use, but work well enough as a training tool to get "close enough." A 2.5% to 5% error in the device at 240 watts, which isn't out of the realm of possibility, means there could be a 5 to 10 watt discrepancy just in the test data. Add that error to other errors in the test set up like wind, bearing friction, rolling terrain, etc. and the errors compound. Inaccuracies aside, as there is no perfect experiment, the information you have is still interesting. Most importantly it shows how our perception is often inaccurate too. I always thought the 700c wheels and tires were faster too, because it felt faster. The purpose of my choosing a flat road was to remove any variations caused by the slight differences in wheel weight. Although far from perfect, my test was aimed at determining only how tire width affects rolling resistance on a paved road with different surface roughness. Wheel weight in this case only matters when the wheel is first accelerating, but at a steady speed the weight differences no longer affect the rolling resistance. All of that aside, your testing points out how different tire treads and compounds affect rolling resistance. It also shows how hills and weight differences do matter. I don't know how much testing Ted King has conducted on different tires/wheels. His race results obviously speak for itself, and he knows what works for himself. Gravel racing, or any racing for that matter is quite complex, and while equipment is a part of it, so too are a bunch of other things. Maybe what he means is that running anything wider than a 42mm on a 700c is the point of no return, at least in his mind, and for a gravel race as a tire on a 700c wheel gets wider it also gets heavier? I think DK has a bunch of punchy climbs, but none more than a few hundred feet at a time? I wonder if he were to run a smaller lighter 650b wheel with a wider tire, the weight would be less and perhaps the extra tire volume would be faster and help to smooth out the bumps better? Perhaps he's already tried this and didn't find any significant advantage? Thanks again for sharing your results and I appreciate the opportunity to share my thoughts too.

[@Peter-tc3ep]

Henrywildeberry I found it most interesting that the knobby 700x38 tires were only 16 seconds slower then the slicks. But again I found tire materials made a huge difference in speed. Harder larger tires were actually slower then softer wider tires, which was hard for me to believe. But I guess soft rubber provided better traction. With going to a bunch of gravel races now, talking with people there including Ted King who was very friendly and actually used the same tires as me. I’ve learned that no one has ever won or placed well on 650’s, everyone I’ve talked to stated they just have too much resistance and a smaller circumference and rolling inertia. Weight on the Rene Herse 700x38 tire is 388g and weight on the same tred Rene Herse 650x48 is 455g so the 650 wider tires are almost always heavier unless they are different materials being compared. The wheelset difference in my DT Swiss the 700 is about 45g heavier over the same DT Swiss 650 set. So total weight the 700’s are about 20-25g per wheel lighter. One would think in climbs wider tires would be better but I have not found that to be true, more softer rubber tends to be faster. Next test I want to try my 700x38 slicks against the 700x28 slicks, I’m curious if there’s any real difference besides comfort. In the few road races I’ve done recently, used to do a lot a decade ago, I’ve notice many riders now use 28 and there are even a few at 30 but less and less at 25. 28 seems to be the new 25. I use the dual crank Shimano power meter which does a good job of not dropping out. My road bike uses an S-works which also works very well. I know my old FSA one used to drop and just average, but modern ones seem to keeps much more accurate information, claimed +/- 1% on Shimano and 1.5% on S-works.

[@Henrywildeberry]

Peter Choma I’m very impressed with all your experimentation. Not many would put in the time. I’m also very surprised by the difference in weight between your two wheel sets. In part one or two of this series I measured the weight of two exact rims of the same extrusion and found the 700c was 100 grams heavier than the 650b and that’s not including the spokes. These were aluminum rims and Carbon fiber, being a very lightweight material, the difference in weight between the two sizes would be less. It makes sense that bike racers chose carbon over aluminum. The reason I shy away from race results as a measurement of comparison is that they are non repeatable experiments. We’ve seen many cases here on the west coast where riders doing mixed terrain races are standing on the podium together where one rider was on a mountain bike and another on a gravel bike with completely different tire and wheel sizes. Just a few years ago people were dismissing tires as wide as 38 to 40 mm as being too slow. I remember road racing on 23s and no one then would have ever imagined running 30 mm wide tires, now 30s are the new 28s.

[@TheDecguy]

I truly love the videos with you and Ms. Cools taking rides through the beautiful California countryside, and stopping for coffee at some small cafe. I also love a bit of science here and there also. As a retired engineer I find that I need a variety of mental exercises to keep me going. I’m currently working on one of these myself. Currently I have about 7 bicycles at my house so I wonder how come I’m still fat! Thanks for the videos.

[@Henrywildeberry]

Thanks Martin! It's hard for me to channel myself into a single format. I like experimenting with different topics, but I realize that's not always a formula for success on KZbin. Thank you!

[@SgtToastieYT]

I'm enjoying this series, my main takeaway so far is don't sweat the details too hard and find something you enjoy riding as the numbers come pretty close and there are so many details beyond just 650b vs 700c in these circumstances.

[@jimmysqueezyronin5623]

Yup, this. A difference of a few seconds on a bike that wasn't built just for speed. However I'm sold on the 650b cause 'im built for comfort baby, you know I ain't built for speed..'🎶

[@johnhorgash9031]

I have been thinking about this for some time. Maybe the pneumatic tire made of rubber combined with the road conditions only go so fast. Its usually a few seconds one way or the other in the differences between tires. Maybe the game changer is hub bearings and aerodynamics or maybe an unknown factor that one has yet to consider! I agree, ride what you like! After all you are the only one that has to like it! Above all enjoy the ride!!!

[@SgtToastieYT]

@@johnhorgash9031 In Henry's earlier videos he mentioned something I really think plays a factor. Weight of the wheel especially as it gets farther from the axle. Getting lighter rims and lighter tires is what I expect to be a larger factor in creating a faster bike.

[@johnhorgash9031]

@@SgtToastieYT lighter tires doesn't mean faster. Heavier rims take more power to speed up but they also are easier to keep going. So if you have an aerodynamic rim that is heavier the momentum keeps it going and the aero benefit makes it faster in the long run.

[@scottatkins8381]

Thanks Jeremy. I enjoyed the video. True the test isn't 100% scientific, but it is a real world test that provides you with the relevant information you need to determine what works best for you on your bike rides. I'll keep riding my 650bx42 tire bike and my 700x25 tire bike. They are both fun, and it's nice to have some variation in what you ride! Thanks again from Texas!

[@bicycleutopia]

excellent video!! youve convinced me. that was a lot of detail work to make that video...geez. very impressive...

[@flpirate45]

Great analysis, you definitely love cycling like most of us. I did enjoyed the redoing of the breaks. And loved the round glasses. Thanks

[@Henrywildeberry]

😎 Thanks flpirate. I'm glad you noticed the glasses.

[@waterboxer87]

I like all things about cycling. I am aware of the narrow vs. wide tire debate and I like hearing from both sides. However, my riding conditions dictate my tire width. I spend 95% of my cycling time on dirt roads, so I prefer tires ranging from 40mm to 3.0." Speed is not a factor; comfort is. I thank you for investing time and effort and presenting more information. Say hello to Ms. Cools.

[@Gieszkanne]

I once read in a forum about the "beeing faster " sensation. This wasnt about 650b vs 700c but just slimmer vs wider and more vs less pressure. On the harder tire you feel more vibration and this gives you the feeling of beeing faster. That was their conclusion and I find this kind of logical.

[@ouzobusiness6435]

Not sure if anyone already mentioned Contact Patch on the road. The fatter rubber is quicker because it provides better traction with every pedal stroke. I'm sure cornering speeds would also be higher with increased traction, or confidence to go faster as a byproduct. Maybe on a not windy day, weigh yourself and bike with different wheels/rubber, fill a water bottle to compensate for the lighter equipment and do a dead roll start descent test, all gravity coasting straightest line possible, this will give you rolling resistance differences. If the speeds are closer or thinner rubber turns out to be quicker, then you sort of know your gains are during acceleration or power/torque application. Thanks for all the great videos. Awesome channel.

[@davidcummings5826]

Nice work on the DIY brake swap! I appreciate your thorough review of the possible influences on your test, it shows your commitment and care for the subject. And most of all, I love your T-shirt! I have a background in biochemistry so it speaks to me! Keep it up!

[@Henrywildeberry]

Thanks David! I appreciate the encouraging comments. I was happy the brakes worked for the test, but I definitely wouldn't want to count on them for the long haul.

[@StructuralModelling]

Thank you for this video! Your experiment convinced me that a 650b tire is not going to make me lag behind during group rides, that was the only thing that made me doubt buying a 650b setup. If you want to improve your experiment even further you could replace average heartrate with average power using a power meter pedals.

[@sharriffwinnhouser237]

LOVE THE SPECKS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[@mikemaxwell2591]

Seriously Mr. Wildeberry those are some fantastic Mr. Peabody and Sherman glasses which made the test very scientific, still catching up. That was some effort, be well.

[@Swoonorama]

Thank you for this extensive testing! It must have taken a lot of work and time! As you already mentioned, aerodynamics could influence your testing once you reach a certain speed. Moreover, you could try the original panaracer gravelkings for 26 mm for 700c and 48 mm for 650b, respectively, as they should have the same compound composition! But I know that it would be quite a pricey video...!

[@bicycleutopia]

where can i get those microscopic bike mechanic glasses?

[@Henrywildeberry]

Every home DIY mechanic needs a pair!

[@ronskayakingandfishing414]

I laughed when I saw those. Not laughing at him, because I would do something like that as well, but they were a surprise to see.

[@theparalexview785]

Kinda reminded me of Sandy Becker's old Hambone character from the 1960s TV show in NYC. ;)

[@KW35-]

Thanks for this test. I think it would be interesting to compare the weight of the two wheel sets. The results are very close, but we have to take in account that this is a comparison of a 26 mm tire vs 48 mm. The 48 gives you much more comfort riding on uneven terrain and is as fast es a narrow road tire. I think that is the most interesting conclusion of this test. That you can gain comfort without loosing speed.

[@chrislang8553]

I'd like to see these tests done on a climb.

[@mcndjxlefnd]

I miss Sonoma County. It looks like you're living the good life out there in west county. Regarding the test - something that is not considered is potential aerodynamic advantages of the shorter wheel on 650b.

[@JaredArchbold]

Great video. While there are variables in the test, I still think this is useful data, and it appears to be inline with Jan's own tests, in which he controlled for all of the variables and still found the wider tires to be faster. I've also found that the skinnier tires feel faster, and enjoy chewing on the paradox of that. It's fun to think that my 54mm supple wall tires on my dirt drop bike could be just as fast or faster than a 28mm tire on my road bike.

[@felixjackson2670]

Yes,interesting. I live in Donegal-West Coast of Ireland. Lots of single track mountain back roads and some forestry tracks...rough roads. Been riding road bike 700x25 for years around these roads. Last year built gravel bike and using WTB 650x47 tyres. Bottom line,650 much more comfortable and smooth ride.Therefore prefer them and can push hard if I choose without suffering bone shaking discomfort. On long group rides,mostly on decent roads would use my race bike 700x25.But the 650’s are SO MUCH better over rough,gravel and on local group MTB rides also. I really enjoy the smooth,versatile ride of the 650’s. Also really enjoy riding my race bike....Great to have both!

[@TomasJ111]

I always appreciate your videos, Henry! Good attempt to measure the difference with a bit of methodology. You need to eliminate a few obvious biases: using similar rims for 650b and 700c with the same spokes, hubs and bearings; using the same brand tyres (e.g. same supple WTB tyres for 26 mm and 46 mm); using a power meter and adapting your effort to the same output; and perhaps consider the aerodynamics of the rims and tyres by having wider 650b rims matching the wider tyres. Personally, I often feel that a rough surface slows me down when rolling on narrow and hard pumped tyres - interesting to see some data backing this assumption up!

[@Henrywildeberry]

There is definitely room for improvement in this test. Tires from the same manufacturer would help reduce variations between carcass and rubber compounds. The rim profile between the two wheels in this test were actually quite close. The 700c is a rim by SunXCD which has an almost identical profile as the Pacenti Brevet rim, namely a low profile box section. What was interesting is the 650b front hub used in the test was a dynamo which has a slightly higher resistance. What's also interesting is the Continental GatorSkin tires have a slightly lower rolling resistance on the rolling drum test compared to a Compass tire. You're right though, the test should be set up with identical parts (hubs, rims, spokes, etc.) where possible. When I set out to perform the test I wasn't prepared to have such similar results.

[@Radnally]

I remember when the industry first started pushing 29er's and part of the narrative was "faster". I think i saw an interview where Gary Fisher was heavily touting the advantages of 29ers.

[@timrice5342]

I watched Giant jump all over 27.5, and now they came back to 29's

[@MybeautifulandamazingPrincess]

It is faster... Smaller diameter wheels are better if you start and stop a lot, but on a smooth continuous ride bigger wheels are better becau they maintain speed way better, that's why road bikes the standard has been 700c for a long time On my commuter bike I have a heavier front wheel, and from my experience it helps the bike to glide on the road even better. And I'm thinking of trying a bigger diameter on the front wheel and smaller on rear wheel to see how it feels like

[@parmijo]

I've done a much simpler test with narrow 700x23 (95psi) on a standard rim vs wide 700x28 (70psi) on a HED ARdennes + rim which took the size out to 31. The wheels were similar weight and depth. Both tires continental GP4000s II. The 23s were only faster on the smoothest straight road. The big tires were faster everywhere else, even on a descent with a lot of tight turns. Strava comparison tool showed I was much quicker in the turns with bigger tires. I felt faster on the 23s most likely due to the NVH (noise vibration harshness) being higher.

[@danalbert5785]

Interesting how I starting cycling in the very early 1970's when American bikes used 27 x 1 1/4 tires and European bikes used 700 C and 27 x 1/ 1/4 went out of favor. BTW, I hated center- pull brakes then and still do today! Long live down-tube shifting, toe-clips, and metal frames! Keep up the videos. I try to not miss any. How to design a "double blind" experiment? I surely don't know.

[@johnhorgash9031]

This is very interesting! I have found that Gatorskin tires are slow and not particularly puncture resistant. My Continental 4 season tires 23 cm are slow as well . The Continental Grand Prix 4000 sii are about 1 to 1.5 mph faster according to my grossly informal testing on chip and seal and smooth roads. Mostly just on my normal rides. I would have to buy new bikes to be able to ride 650b wheels! I wonder how much bearings and spoke count contribute to the equation. Switching to my Zipp 404 (the old style) wheelset gives me a 1.5 to 2 mph increase compared to my Ksyrium elite wheelset. And the Zipps do feel faster with less effort. I have. 20 inch x 1.5 inch and a16 inch x1.5 tires on my old recumbent and they roll just fine. You really have me thinking!

[@trek520rider2]

Check out Hambini for info on bearings.

[@Bishieboi]

Henry-"Its a pretty rough surface" Me looks at every road in australia made that exact same way and often rougher since they melt in summer and we are left with huge potholes everywhere 👀

[@dlevi67]

For that matter, roads in (my part of) the UK seem to be much closer to how you describe the ones in Australia, despite the lack of melt-down. Maybe it's to do with driving on the left?

[@MybeautifulandamazingPrincess]

They should make the roads from concrete instead of asphalt or tarmac, then it wouldn't melt and it would be smoother. Here in TX and in AZ a lot of roads are concrete and they are durable from forming potholes

[@StanEby1]

Very well done.

[@recyclespinning9839]

The secrete to fast wheels is better rolling bearing and lubed... But really I have a Casati Ellis which I thought was fast, but then purchased a Schwinn vintage 1990s PDG 40 mountain bike ,off of craigslist from a guy who worked at Schwinn for 120 bucks . It had Continental town and country tires. I found the bike super comfortable and fast. I think for road wide tires are way better...

[@toddmcdonough]

My theory is that it comes down to pedaling efficiency. Less road noise (random vertical movement) makes for a smooth round pedal circle. Kind of like the use of anti-backlash in a geared mechanical system. Over the span of a longer effort, I would expect to see an additional advantage due to lessening rider fatigue and the elevated morale that goes with it. Right now I'm laughing at myself for trying to sound like a scientist, which I most definitely am not.

[@Henrywildeberry]

It sounds like a good theory to me. On the rough section my hands were vibrating noticeably more on the 25's. I also had to concentrate more to keep a consistent heart rate. Little bumps in the road would disrupt my ability to keep a smooth and consistent pedal cycle. The bike would buck back more often throwing off my cadence. The wider tires felt like I could keep a more consistent pressure on the pedals even on the small bumps.

[@perryleopold7555]

It might be interesting to plot the data points using Least squares regression.

[@TrevorOleniuk]

I am curious how the 650b x 48 would compare to 700 x 40 or really any size larger than 25mm. I wonder if those would be faster or if the extra weight would affect speeds.

[@ronskayakingandfishing414]

My opinion is that the test shows some good points but I think what would help would be: 1) use of a power meter instead of heart rate monitor. Strava would give good info on how much power is used for one of your rough/smooth segments when power meter was used. I finally bought some Favero Assioma road pedals to track my power outside although my preference is mtb pedals. The SRM PowerMeter SRM X-Power is supposed to be coming out which is an XTR-style MTB pedal but they keep postponing release date and I also wanted something a little more proven. DC Rainmaker gives the Assioma good reviews although the cleat style is not his favorite. 2) Definitely agree on using different tires. I've used the Gatorskins before and like them fine for winter riding when the roads are wetter and more "junk" on the roads that could cause flats. But feel they are on the slow side. Maybe you could get some similar Compass tires and use them. Say the 700c Cayuse (26mm wide) vs the 650B Babyshoe Pass at 42mm wide. But I would try to run both either tubeless or with tubes to insure closer comparison. I always thought the 650B might be marginally slower just due to greater rotational weight, but not slow enough to give up the comfort when doing great distances. I think that is even Jan's position... they're not faster per se, but for a 200 or 300 km (and longer) brevet, the added comfort from the 650Bs is worth any slight speed differential. Thanks for the test and data, I think this was a great step in trying to prove things to yourself and others.

[@franklynwu]

Such an informative video!

[@davidbee9563]

Thank you for another thoughtful video to try and test in the real world. Unlike the lab, you cannot control all the variables. The question is what you started with: Is the difference enough to be significant? If you discount the biggest variation, the answer would be no. However, one could conclude that running a wider 650 by 47 tire gives a more comfortable ride without giving up efficiency. How about a test of pressure variation vs speed and comfort? Using a bike with 650 wheels and another with 700 try a similar pattern but vary the pressure by 20 psi. I think it should demonstrate that for both sizes higher pressure does not equal more speed.

[@ddahstan6876]

Wow. Truly appreciate your "real world" tests!! Now I know what my favorite wheels are, considering I've been trying hard to find an afordable yet above average bike for so long with 650B wheels. Besides, it would be much better for me to be on 650b wheels than 700c because I'm barely 5' 😅. By the way, is that the Community Bike in Santa Rosa?

[@Korina42]

Interesting experiment, and after reading (and/or skimming, TBH) the comments, I'm more convinced than ever that my cushy 26"x2" tires are the best for me and my ride. 😉 I do need to know, where did you get that t-shirt? I love it! Be safe and keep riding!

[@the_nondrive_side]

Blasting the rear wheel on a curb in an emergency hop... Always fatten the tire up and run the pressure higher than supple. I only run a 650-47 rear with a 700-40 front

[@smitajky]

I have tested tyres by letting a bike roll on a 10km constant small downgrade. I found that the quality of tyres were more important than the size. On one set of cheap tyres the bike wouldn't even roll. On other tyres I typically rolled between about 28 and 32 km/hr. The differences between other quality tyres was so small that it really didn't matter except possibly for racing. The best performance I measured was 700C 32 front and 35 rear combination.

[@Henrywildeberry]

Cool! Thanks for sharing your experiences.

[@biketrailing4277]

I'm curious if vibration dampening played a factor. I have 700c tires and typically ride at 120 (or close) PSI. For me, the smoothness of a road make an enormous difference. I lose a lot of speed on bumpy roads. I could only imagine a wider and softer tire would dampen those bumps allowing more efficient pedaling.

[@randallsmith7885]

I have been wanting to have a bike that offers comfort and the ability to ride on any surface. 650b seems to supply the answer. 650b suffers no penalty on smooth roads vs. 700c and offers superior speeds on rough surfaces.

[@JustRideZipp2001]

I've done 100's of TT races and my two TT bikes the Zipp2001 and Lightspeed blade were both 650 wheels. I always felt I got up to speed quicker with the 650 wheels, and saving a few seconds is big in a TT race.

[@Henrywildeberry]

That's interesting to hear about your TT experience. It seems like the smaller diameter wheels would also have better aerodynamic advantage.

[@JustRideZipp2001]

@@Henrywildeberry I'm sure it might have a minor aero advantage also.

[@robindegu7294]

Hope cycling about does a study on this as well

[@Henrywildeberry]

Please do! More peer reviewed studies the better. This is just me being curious with very limited testing equipment. I imagine this would make a great Masters Thesis for an inspired engineering student who also enjoys cycling.

[@peterbee8892]

The difference seems marginal so enjoy the ride on whatever bike you have. Ps I'm a big believer in wider low pressure tubeless tyres.

[@tomrecane6366]

You didn’t test the difference between wheel sizes. You tested tire widths. Still very informative and I am convinced wider is better. The next test should use tires of the same width and make on the different rim sizes. Keep up the good work!

[@marcbemelmans6139]

Tpi numbers are very important. Uphill smaller airchambers might climb easier.

[@odgreenoutdoors20]

I don’t think I have seen anyone ask you in the comments about why you chose (Henrywildeberry ) as your channel name? Is there a story behind it?

[@michaelkennedy4444]

I’ve had this discussion with a guy at work who swears by 25C tires yet complains about the rough ride. I told him to go up to a 32C and he would have a more compliant ride and not lose any speed. Now these are amateurs we’re talking about here. But for myself I would never go back to 25s again. As a matter of fact my new gravel bike is running 40s.

[@timrice5342]

if all people run is packed dirt or chip n seal GP 5000 tubless in a 32C is a fast tire!!!!!

[@phillipcowan1444]

Hmmmm. You've got the wheels in my brain spinning. I have three bikes that all have Velo Orange hubs,Velocity A23 rims,DT 14g spokes and Compass tires. I guess it's obvious when I find a combo I like I tend to obsess on it. The only real difference between them is the frames. Bike No.1 is 80's Giant lugged steel w/ 700cx32 Stampede Pass. Bike No.2 is Raleigh One Way w/ 700cx38 Barlow Pass. Bike No.3 is Toussaint Rando w/ 650bx38 Loup Loup Pass. I don't own a heart rate monitor but I s'pose I could borrow one. Alternatively I could do a coast down if I could find a downhill section long enough (not easy in N. Illinois). This would sorta recreate the type of test Bicycle Quarterly did a few years back. I guess I would be preaching to the choir though because I'm already convinced that the fatter tires make very little difference in my speed or times over known routes. There really is no valid reason to continue riding the 23mm 'prostate pounders" when the supple 38-48's are as fast or faster. From your raw numbers it looks like you're picking up 5-6 seconds in each ~5min. pass. That would scale out to about a minute per hour. Not very significant on a social ride. Love them glasses man!

[@Henrywildeberry]

Prostate pounders, lol! There's a number of tests we could run and I'm sure there are situations were a 700c x 23mm tire is faster, but what I learned is how perception doesn't always equate to reality. What feels faster may not actually be faster. It would be great to see more tests performed. Jan Heine has provided some very valuable insight. His thoughts on vibration losses is something I think is spot on. Lots of people have gravel bikes with disc brakes, so swapping wheels/tires is a snap (a simple twist of the thru-axle). In my case I had to muck around with some old center-pull brakes.

[@malcolmtaylor518]

We need the community bikes idea in the UK. As regards tyre sizing and speed, as a non competitive touring cyclist I find the psychology of cycling interesting. I enjoy cycling and as I get older like to think I'm keeping good speed. As you say fat tyres give the perception of sluggishness, so when I can I always use narrower tyres even at the expense of smoothness in the ride. Psychologically fat tyres don't do it for me. I've never done an audax, maybe that would change my mind. In the quantum realm observing a process interferes with the outcome, maybe that's what happened here, ha ha!

[@ridewithgae1467]

Cool Video

[@timrice5342]

here is my take on it all.... the time difference is nominal to the point of being pointless. so there is no argument that more volume, is a nicer ride. So the question, (or debate),. It is question for me, do I want 650x47/48, or do I want 700x 42 like a wtb resolute or a 700x44 snoqualmie. yes Donnely has some nice 650x50 but at a huge weight penalty.

[@raul0ca]

This video confirmed my hatred of Gatorskins. When I ride on them I feel like I'm riding on a bulletproof vest. I once got a pair of used Vittorias from ebay and it felt like a magic carpet ride though with the amount of felt in those things it was probably more like a used car carpet ride.

[@reehren]

Great stuff! Really interesting test, as well as the comments! In your experiment, of course there are going to be differences in wheel size, tires, rubber compound, spokes, hubs, etc., but it's still a good exercise from the perspective of doing a ballpark comparison of overall differences between a typical 700C wheelset with narrow tires that you've used in the past against a 650B wheel set with wide tires that you're using now, just to see if you're giving up anything for that increase in comfort. I've never done any kind of test like this one, but I love 650B x 42mm, and I'm never going back to 700C x 23! What I'm really interested in seeing is how 42mm tires of a given compound stack up against 48s (at least for road use). I've been wondering that, by the time a tire size increases from the 20s to 42, you've already gained enough tire volume to reduce vibration losses, so when you go even wider now to a 48, you might get marginal gains from that further increased volume, but now you have the drawbacks of extra tire weight, rotational inertia, frictional losses at the tire patch, and air resistance (insignificant, but still). In other words, are there diminishing returns? (Of course, this is all goes out the window for rough stuff!)

[@Henrywildeberry]

Robert - I figured when I first set out to do this experiment I would see a much larger difference in the results with the 700c taking the lead. Had I conducted this test at different velocities in order to include wind resistance things would likely turn out differently. However, the take away for me was to see how my perception was inconsistent with the test results. Many have said the Gatorskins I used in this test were a terrible tire choice for comparison. Even though I agree I still thought they would be slightly faster. Bicycle rolling resistance shows the Gatorskin's having a rolling resistance of 21 watts at 80psi (@18mph) and the Compass Barlow passes at 30 psi have a rolling resistance of 28 watts. They didn't test a 48mm wide Compass tire at 30 psi, so I can only assume it's less than 28 watts. The 42 to 48mm wide test sounds interesting and given what I've seen here the test set-up is going to need to be very precise. The 42's are probably a better tire size as you've pointed out for performance especially considering the difference in weight. The gravel races appear to be winning on 700x38-40. Would a wider tire on a smaller rim help them? On softer soil (where a wider tire can disturb weight over a larger area), or chunkier gravel perhaps? However, for an all-around "mixed terrain" tire for riding gravel, single track, and over rough broken asphalt, the 48's are excellent. It does take a lot of care to get them to fit with a set of fenders, and a narrow q-factor which makes the 42's a good alternative.

[@trek520rider2]

@@Henrywildeberry Jan Heine makes the point that harder tires do seem faster.

[@Henrywildeberry]

@@trek520rider2 Yes, he does, and I wanted to independently confirm his conclusion.

[@ericpmoss]

Would it be easier for you to just do the front wheel? It would make it a lot easier to avoid other variables like worn cassettes, unequal tensioning of rear wheel, etc. Who knows, it might turn out that one is better off with different front/back.

[@TannerDeGiovanni]

But what about wider 700c tires? It seem like road bikes/gravel bikes are lagging behind mountain bikes. 29 (700c) is pretty well accepted in mountain bikes but there are wide tires. I wonder how well a 700c tire that was 48mm would fare in this test. Obviously not all frames can fit this.

[@Henrywildeberry]

I don't know if a 50mm wide 700c tire will fit on my bike but that would be another fascinating test.

[@martinjames672]

I prefer smaller wheels with fat rubber pumped up hard! This is the goldilocks combo for me. On quality tyres (tubeless are best) the supple sidewalls deliver the comfort, and the high pressure reduces the rolling resistance. But then I weigh 100kg...

[@davex5424]

Why are you trying to achieve the same rolling diameter?

[@Henrywildeberry]

davex5424 mainly to keep the bike geometry and handling the same.

[@sheilastallard]

My husband as a single speed with 23mm tyres pumped up 120 psi . He bought a cheap Decathlon cycle with 28mm pumped up to 80 psi. He tells me he can feel much difference between bikes except the singlw speed is a bit harsher. We both don't do any gravel rides. KEEP SAFE!! ps are you coming out of lock down?

[@Henrywildeberry]

I'm glad to hear all is well over there. Yes, they are loosening up the restrictions now. The parks are opening (finally!), but we're still keeping a 6-foot (2 meter) distance. Restaurants are open, but for take out only. We still have travel restrictions in place, but bike riding and things like that are okay. I'm waiting for the travel restrictions to open so I can go bike touring.

[@sheilastallard]

@@Henrywildeberry We are waiting to see what our PM come's up with. I would prefer lock down to continue if it means we get Covid 19 well under control. Like a lot of people our age we have grand kids that we don't see except via "Facetime" , but I would rather wait to see them . KEEP SAFE

[@Pillokun]

We need custom wheel/frame sizes depending on the size of the rider so that every size of the bike looks exactly the same proportion wise. Hate when the bigger bikes looks so twisted if it is a big size. Sure it would have be a bit unfair in some situations, but then the weight of the bikes should also be in proportion to the size of the rider. This is 2021 not 1860!

[@odgreenoutdoors20]

If I may ask a question, I just bought a 1984 Raleigh kodiak touring bike and it’s in near mint condition with original tires that look good, I don’t think the bike was ever ridden much at all, I’m not an experienced rider and looking to do over nighters on it , so light weight touring and getting in shape and loosing weight.. so I was wondering should I upgrade the components? To me it rides like a Cadillac but I haven’t ridden many bikes..so if I do some upgrades what would you recommend ?

[@Henrywildeberry]

Congratulations on scoring such a sweet bike! It doesn't sound like you need to do much, if anything, but here are a few of my thoughts. Saddle, saddle, saddle. This is going to be the hardest choice in your life, and it's going to take some trial and error, but get a good saddle. A good saddle may not feel comfortable right away, but over time you'll find the really soft saddles are actually uncomfortable. It's hard to beat a good Books saddle, but not everyone likes them, so prepare to experiment. Replace the brake pads, cables, and shifter cables. I would at the very least service the bottom bracket and replace it if needed. I would also check the headset and replace if needed. A loose or worn headset is the worst! Remove and clean the quill stem, add grease and reinstall. Check over the stem and handlebars for cracks. If you see any cracks or anything even slightly questionable replace them. DO NOT take any chances with older aluminum parts, especially the stem or handlebars. Look over the fork blades, fork crown, and steerer. Although very unlikely should you see any cracks or fractures (hairline or otherwise) take the fork to a frame builder and get it fixed or replaced. A frame builder can make a new fork with all the bells and whistles and make it fit perfectly with your bike. Check the chain to see if it has stretched and replace as needed. Check the hub bearings to see if they are loose and service them as needed. If these are loose ball types (which they probably are), you can get new ball bearings from the bike shop. It sounds like the tires are good, but personally I would replace them with a new set. I prefer fast rolling wide tires like Rene Herse, Gravel Kings, Pari-Moto, etc. Panaracer makes a whole bunch of fast and light tires for tubes or tubeless for many brands out there. Other brands make wide fast tires too such as WTB, but I haven't ridden them. A traditional touring tire with a thicker tread and puncture belt is fine too if you're worried about flats, but it will feel slower and sluggish. Fixing flats is no big deal and it's good to have few now and again to remind you how to fix a flat, but also how to look out for sharp objects on the road. I've gotten about 3 flats in the past 7000 miles of road and off-road riding on super thin tires, so for me the extra light and supple tires are worth it. I understand not everyone wants to worry about their tires on a long ride. Carry a spare tube, patches, and tire levers. The main thing is to ride it, and ride it a lot. The more you ride it the more you'll see what it needs. Long term, you could upgrade the wheels. To do this you could have the rear hub spacing cold set to 130mm. Read about this on Sheldon Brown's website. Doing this will allow you to run newer hubs and a 9-10 speed cassette. You'll have more gearing and hub options to choose from. You might want to consider upgrading the brakes too. A modern set of Paul Component Engineering or Rene Herse brakes will provide excellent stopping, or you could also switch to v-brakes. Rim brakes have come a long way in terms of brake pad compounds, and brake/lever design. The only problem with rim brakes is finding good advice about them. All the best and enjoy that new (old) bike!

[@odgreenoutdoors20]

Thanks for the advice, I have checked for cracks and no cracks anywhere so yea it could use a full tune up and go with a sealed bottom bracket and change the brake pads. I will definitely get new touring tires and was thinking of using tuffy tire liners, and get a nice brooks saddle and new wider Handel bars, probably at lest a 38.1 inch , some fenders and front and rear touring racks, I like the swift front bag you have and will look into one of those....I think I will keep the gearing and wheels original for now and just get some miles on it and get in shape before I think about upgrading the wheels and gearing. Yea can’t wait to do some overnight outings on it ...well again thanks for your advice and love your videos and subscribed

[@Henrywildeberry]

@@odgreenoutdoors20 Cheers and have fun!

[@odgreenoutdoors20]

After thinking about it I believe I’m going to go with a bob trailer and not do the front and rear racks, the bob does better in headwind then panniers, and I will get me one of those front bags like you and ms cools have ,

[@konstantinthiel3978]

Thank you for this interesting video series! I really enjoyed it, especially your (self-) ciritical approach to all the assumptions and simplifications made. For me, this suggests that you're familiar with philosophy of science ;-) I noticed that you didn't do the calculations from part 2 for the actual tyres used in this experiment. So I tried to do them on my own. You said you went with the following pressures: 48x650b: 30 psi 25x700c: 80 psi I.e. the contact patch of the 650b is larger then the one of the 700c. If we assume the following outer diameters of the wheels (simply by interpolatiing your table from part 2): 48x650b: 684 mm 25x700c: 672 mm and then follow your calculations, we obtain a larger angle "phi" and thus a larger rolling resistance for the 650b: 48x650b: 19.56 N 25x700c: 14.35 N Provided that I did not make an error, the calculations suggest that the 700c is quicker. So the experiment actually puts the contact patch rolling resistance theory into question. Anyway, I think the most promising way to improve the quality of the results is to add more repititions while controlling for more of the variables. All the best for your future! ;-)

[@Henrywildeberry]

Wow! Thank you for taking the time to review the tire choices and running through the numbers. It's worth mentioning, the force we're calculating with this method neglects to take into account the rebound force as the tire unloads and returns to its original shape.

[@marcbemelmans6139]

What type of brake do you use? Thank you for replying.

[@pavelcekal2917]

Hello, I would like to get on my bike: Triban GRVL 520 Sram Apex 1x11 buy rims DT Swiss G 1800 Spline. And according to the manufacturer, I can use 650x47 or 700x42 Please advise, What option would you choose from my options?

[@dougturner2408]

If you used fenders on the 650 and no fenders on the 700 then the comparison would be compromised because fenders add aerodynamic advantage.

[@ReVoltaire]

I didn't totally follow the epilogue about your plan to do more testing. Like the part where you mentioned restesting at race speeds like 25-30 mph. Unless you meant coasting downhill (?), I can't imagine anyone being able to sustain those speeds for any period of time on a bike like that running fat tires at 30psi. It's actually pretty hard to sustain 25-30mph on flat or slightly rolling terrain for 5 min even on a light, aero, road race bike (unless you have an insane tailwind boost, like you can sometimes get consistently on Hwy 1). Another local cycling blogger, NorCal Cycling just issued a video in which he compared a climbing vs. and aero bike (kzbin.info/www/bejne/hpnOkqWCbrqLa80). he used a power meter as a constant and rode a longer time/distance. He wasn't going for max test speeds, just a moderate steady effort at his level. Differences were minute to non-existent (IMO). I ride consistently with both a power meter and a HR and I think the power meter data is much more of a "constant" of what force you actually applied in each test than the HR. As you likely know, among other issues, once you're more warmed up, you can usually sustain a higher effort level at the same or even lower avg HR.

[@Henrywildeberry]

Thanks Patrick. I'll watch the video you linked. Initially, when I set out to perform this test I had imagined the results were going to show a much larger difference between the two tires. I figured even the Gatorskins (which are considered slow) would still outperform the 48mm pari-moto/gravel king tires by a large margin and the discussion would be over. However, what surprised me most was how close the results came out in favor of the 48's even after multiple trials (both cold and warmed up). The differences are down to a handful of seconds over a 5 minute test. When I suggested more testing using better testing (more accurate) equipment, such as an accurate power meter (as you mentioned), and tires matched more closely was to see if this test was flawed. Perhaps the Gatorskin is such a slow tire it makes it look like the wider tires are faster?

[@peterquest6406]

I ride 27*1inch.i don't fit in anywhere 😢

[@Daniel-yf9iy]

Interesting.

[@ccjelley2390]

What about rider weight? Try it again with an extra 56lb load! What about steep hill climbing [difficult to do a control....] ? I like skinny 700s and used them on and off road.

[@FerventDissent]

I like your work here, but the tires are different construction. Thank you or your work.

[@davex5424]

Henry I watched the video. Please correct me if I am wrong, but your test was completely flawed. If you want to see the difference in wheel diameter, that is 650 vs 700, then you have to use the same brand tire and the same diameter tire. If you want to see the differece

[@TomasJ111]

Davex, I think you may have misunderstood the setup of a bike with different wheels. For the tyres to fit within the frame and fork, a wider 46mm tyre fits if the diameter is adapted to a "650b" wheel (584 mm diameter rim), or alternatively, a 26 mm tyre fits on a "700c" wheel (622 mm diameter). The total diameter of rim+tyre is almost identical on these two options. It would not work with e.g. a fat tyre on a 700c wheel.

[@rinaldyfaustino8352]

hi, totally out of topic, but could you pls share what are those leather bar tapes that you are using in this video? and i noticed that you're not using them anymore. also are those old shimano hubs on the 700c wheelset? thank you. hope you reply.

[@Henrywildeberry]

The bar tape was by Velo Orange. They are a sew up type, so best to use with non-aero brake levers. The hubs are SunXCD.

[@davex5424]

continue If you want to see the difference between diameters, 24 vs 48, the you should use the same diameter wheel and the brand tire. Do you agree?

[@Henrywildeberry]

Having the same brand tire made with the same materials would help eliminate the possible variables across different tire manufacturer's. The exact rolling diameter will still be hard to achieve in real life, but a 25mm wide tire on a 700c wheel is very close to a 650b x 48 in terms of rolling diameter.

[@tomnorton8218]

What's the story with the glasses!

[@bengt_axle]

More importantly, how the hell do you manage to get your hair cut during these (shutdown) days?

[@astrayagrarian]

8638marc lmfao

[@ryanwitt]

Lots of great KZbin videos on cutting your own hair! I tried it and didn’t turn out too bad!

[@josephfarrugia2350]

Recorded before lockdown.

[@Henrywildeberry]

This was DIY trim😂 I actually filmed myself cutting it, but wimped out including it in the video. I learned how to cut my own hair with a good set of barbers clippers, and two mirrors. Start with a #8 guard on the sides and work down from there. I taper to a #4 on the back and around the ears. The top wasn't cut (that's a lot harder).

[@ryanwitt]

One video I saw recommended thinning shears in addition to the clipper. I ordered some and they really worked to clean up the rough edges that a self-trim job leaves!

[@JosephDowski]

Thanks for the vide Jeremy. I'm curious what piece of software you were using to present that grid of test results? Even when she's not in the video #misscoolsrules :)

[@Henrywildeberry]

Thanks Joseph, the software I used to display the data is called Numbers. It's a free app that comes with the Mac.

[@RidingEasttoWest]

Why aren't all the guys riding the Tour on 48mm 650B wheels then?

[@RidingEasttoWest]

@Hank Chinaski Yeah mostly I was being facetious about this. The guys at the top of the sport who have virtually every pedal stroke measured by power meter and plotted against the resultant speed and distance are not riding with 40+mm tires on their bikes. I've run 700c's with 23,25,28,32 and most recently 38mm tires and on relatively smooth road narrower tires are faster though I personally prefer 28mm as the best compromise between speed and comfort. These plumpies that everyone seems to be touting have a lot of advantages in comfort and ride quality but speed vs. watts of input power is not one of them or the pros would riding them.

[@sifuerik]

@@RidingEasttoWest spot on! Wider tyres definitely more comfortable but they are not faster than narrower tyres.

[@danfuerthgillis4483]

Lmfao 4:23 ! Nice mechanic specs

[@biking261]

I notice you run a generator on the 650b wheel even with that the wider tyre was faster.

[@Henrywildeberry]

Yes, excellent observation! With the light turned off the dynamo has a very low rolling resistance.

[@biking261]

@@Henrywildeberry I think that is a SON dynamo and yes it has a very low resistance due to it's high quality but I read somewhere even with the light off you will have around an additional 3 watts of rolling resistance. A resounding victory for the larger volume tyre

[@waffles6095]

What kind of 650b rim tubeless you using , what website can I buy? Thanks

[@Henrywildeberry]

Hi Benny. I'm using Pacenti Brevet rims.

[@waffles6095]

Henrywildeberry thanks

[@garypostell5268]

Why not a 700 x50 c ?

[@Henrywildeberry]

We covered that in the first two parts.

[@ryanwitt]

Do you enjoy 700c tires more on shorter, fast rides? I can imagine feeling fast has a value in itself if you have a shorter ride. Assuming you even do short rides anymore. 😂

[@Henrywildeberry]

The feel of a fast road bike definitely has value, and I'm sure if we tested these tires at a wider range of speeds, and better tires, the narrow tire likely has advantages. Tubular tires are supposedly even faster than the best clincher (the Gatorskin is far from close to the best clincher). I wouldn't call this test a final conclusion, but an open invitation to determine the curve where a narrow tire actually has benefit. With the type of mixed terrain and long rides I enjoy doing, it's nice to see that at normal cruising speeds I'm not actually going slower, even if it feels like it. When you add the versatility and comfort of a wider tire to it's longer life, it makes sense to me for an everyday tire.

[@ryanwitt]

@@Henrywildeberry +1 for testing those new FMB tubulars from Rene Herse! Do you have a patreon to help pay for equipment?

[@NinthwaveThe]

Can you refresh my memory... When you built your Fitz, why did you go 650B?

[@NinthwaveThe]

I have just started the process of building a do-it-all-rounder and hesitating between 650b and 700c.

[@Henrywildeberry]

I went with the 650b because these days there are lots of options in both slick and knobby tires. 650b wheels are lighter and stronger, and even with fenders there is less toe overlap. 650b makes it possible to have a normal chain stay length while still fitting that plush wide tire. Fenders fit both in the font and back more easily. 650b tires are known to have fewer flats and tend to last longer. 650b bikes can share similar frame geometry as a road bike but with wider tires. That's a few reasons but if you have a bunch of 700c wheels you may want to stick to that, which, is why think we don't see more people riding 650b.

[@NinthwaveThe]

@@Henrywildeberry Thanks for your input. I don't have any leftover wheels. I have a 200$ 26" hybrid with studded tires for winter and a 300$ Raleigh Carlton for 3 season commuting. Being 169cm (5'7") with 74cm (29") inseam, I find myself that my toes are close to the fenders on the M frames. Your arguments convinced me to go the 650b way. Thanks again.

[@Henrywildeberry]

@@NinthwaveThe I think you're going to enjoy the 650b size.

[@NinthwaveThe]

@@Henrywildeberry Wider tires is the way to go for me, especially now that I am in my mid 40s. I did not mention that I have a carbon road bike (for sale) that came with 23c and max 25c clearance. With our road conditions, it has been a while since I did not have fun riding this bike. In november, I took my girlfriend's old CCM with 26" and fitted 2" marathon winter (studded) and rode it all winter. Apart from the rolling resistance, I enjoyed the comfort of those large tires. When you have been riding a road bike for almost two decades, you end up believing that this is how the road feels until you revert back to your childhood/youth 26" wheels and realize that, although those beaters are nothing close to "performance" bikes, still you enjoy them more. It's quite a turn up... Then I bought the Carlton for a 3 season commuter. But the idea of having a custom built all-rounder is haunting me and 650b vs 700c is certainly an important question. Thanks again!

[@TimSchmidt_art]

Where can I get that shirt?

[@thomasmuller986]

I'm 6'4" long person and I even look much more stupid on 650B than I already do on 700C. Case closed, sorry for science.

[@davex5424]

Henry Your test may be flawed. One tire is 23mm and the other is 48mm. Personally I think this may be more important that wheel diameter. I have not watched the video yet. Now I am going to watch it.

[@alexcanlas1753]

What I think? I think I just wasted my time here in this compromised experiment.

[@Freightlinerbob]

700c are obviously better in every way, unless of course, you happen to own 650b’s.......

[@jacobmusha7188]

Good effort but there are too many variables to determine which ones are at play here. The main problem is the two completely different tires used. The same tire construction *must* be used. Example: Compass 700x26 versus Compass 584x48. Ideally the same rim extrusion and hubs would be used as well to keep the weight issue out of it. Heart rate is also questionable, a power meter and keeping the bike at a constant speed would be much more useful. Multiple test runs are good but a statistical analysis should be performed to determine if the differences are real or not. Ultimately Jan Heine's work speaks for itself, though I think he's only tested on smooth pavement. However, it's easy to predict that a wide tire at lower pressure would be even more beneficial on a rough road.

[@orsations]

Using your heart rate as a proxy of power applied to the pedals is the same as looking at the gas mileage efficiency of an engine to measure how long a piece of string is. The only valid conclusion here, and you've mentioned this yourself, is that some tires+wheels combos are faster than others.

[@ClockworksOfGL]

Downtube shifters.....my man. 👊

[@rondvivre3636]

NO! Just NO! Everything about this video is WRONG! You begin by titling this video as “..650b vs 700c..” indicating a comparison test between two different rim diameters is forthcoming, but no, in your description you immediately jump to “.. the differences between narrow and wide road tires..” Make up your mind, diameter or width, changing both at the same time results in a meaningless, worthless comparison. Then you proceed with multiple other variables to tire types, spoke count and hub differences and presume that your heart rate is an adequate equalizer ignoring variables presented by your own endurance fitness, wind resistance, air density etc.. To do this properly, first settle on what is to be compared, diameter or width. If diameter is the thing, then use identical hubs and spoke counts, use rims built from identical extrusions and tires built on identical carcasses such as Continental GP5000s in 25-622, 28-622 (700c) and 25-584, 28-584 (650b) with similar tubes. - - - If width is the thing, one set of wheels will suffice, tires must be of the same construction and series. This has already been very well done by bicyclerollingresistance.com. They tested (among many others) Continental GP 5000s in 23-622, 25-622, 28-622 and 32-622 sizes, each at four different pressures and repeated the tests with both butyl and latex tubes. For each size, rolling resistance was lowest at the highest tested pressure, resistance increased as pressure decreased. All across this test set, the widest tire had the lowest resistance when all else was equal. Rolling Resistance at Recommended Air Pressures (15% tire drop) test results showed the narrowest tires the fastest. www.bicyclerollingresistance.com/specials/grand-prix-5000-comparison They also compared Schwalbe Marathon tires in 32-622, 37-622, 40-622 and 47-622 sizes where the 37mm width was the fastest. www.bicyclerollingresistance.com/specials/schwalbe-marathon-32-37-40-47 Note that in both test series mentioned, there are still variables in tread thickness specs between sizes among the same family of tires. There are many other, very well controlled and valid experiments/tests documented at bicyclerollingresistance.com. - - - If/when a test such as you assert to present is beyond your skill set and/or beyond the capabilities of available testing measurements and materials, then, please stop right there and waste neither your viewers' nor your own time. Also, “pseudo-science” is “fake science”, it's right there in the “pseudo” part. All you've shown are apples and oranges. - - - Fact; When all else is equal including the contact patch area, a wide contact patch will always have less rolling resistance than a long one.

[@Henrywildeberry]

Hello, and thank you for your thoughts. It a sounds like you may have missed part two of this video series. In short, we are exploring how equal rolling diameter using different width tires may affect rolling resistance. This test, while not perfect by any stretch of the imagination, was a first pass to see if there is a significant difference in rolling resistance on a real road surface, not a smooth rolling drum in a controlled laboratory setting. While laboratory studies are informative, the results may not predict real world outcomes. In conclusion of this video, the results were much closer than I had imagined and more experimentation would be very interesting.

[@rondvivre3636]

@@Henrywildeberry I just read the transcripts of your Parts 1 & 2, there too you fail to compare like with like with only a single variable. FYI, I've very interested in converting to 650b, I'm finding little of real world use to me in your presentations to help me make the decision. You compare 650b x 42 with 700c x 26!!?? Because the OD is the same? How about 650b x 42 vs 700c x 42 or 650b x 28 vs 700c x 28? You know, one variable. - - - The test www.bicyclerollingresistance.com/the-test Does not use a smooth rolling drum as you've just asserted, but a diamond plate drum to produce a repeatable, rough surface. Further, your choice of a Gatorskin to compare to is a poor choice indeed, it ranks 78th out of 84 for rolling resistance among the tested tires listed. www.bicyclerollingresistance.com/road-bike-reviews Sadly, I've found no proper testing of 650b sized tires. If you want to compare high performance tires, do so. Don't compare an old design, flat resistant tire to a Kirk Pacenti designed, performance tire. - From BRR; “..The Continental Gatorskin has been around for a long time and is well-known for its excellent puncture resistance qualities. This tire is available as both a folding and rigid version. The tire I'm reviewing is the folding 700 x 25 C version of the Gatorskin. Continental specifies this tire as a tire that can be used on the way to work or as a training tire. They seem to emphasize the puncture resistance qualities a lot, but nothing is said about rolling resistance...” www.bicyclerollingresistance.com/road-bike-reviews/continental-gatorskin-2015 - - If this link works; www.bicyclerollingresistance.com/road-bike-reviews?b=continental&maxweight=401&t=tubetype+%28clincher%29&max=24&min=6&minpr=6 It limits the listings to tube type Continental tires. You've chosen one from the bottom of the list with almost twice the rolling resistance of those at the top, Your confirmation bias is clearly displayed. - You have/use no power meter, you 'measure' wind by tree sway. You're still stuck at 'pseudo'.

[@Henrywildeberry]

​@@rondvivre3636 You're going to have a hard time finding real world test information comparing 650b vs 700c in a practical field test without introducing a number of variables that can be criticized. All experiments come with a certain degree of error. The are a number of reasons why I held the outside diameter of the tire constant for my experiment. First, the diameter of the tire affects the direction of the forces relative to the hub. Second, a larger tire on the same wheel is heavier with a higher rotational inertia. Third, a heaver tire is slower on a climb. Forth, a larger tire may not fit with your frame geometry or toe overlap. So you can see the point of the test is to see if a heavier tire/lighter wheel (e.g. 650b) is equal or better than a lighter tire/heavier wheel (e.g. 700c). What's missing in a lab test is how the tire responds to different surfaces. Jan Heine from Bicycle quarterly suggests a narrow tire will roll slower due to vibration losses caused by the narrow tire vibrating at a higher frequency. He has cited a case study conducted by the US Millitary where they measured the energy absorption of a tank operator driving a tank while seated on a hard seat vs. one on a vibration isolated seat. It turns out the human body was capable of absorbing up to 2000 watts. What he is suggesting then is that the narrow road tires are likely slower because your body has to dampen the extra vibrations caused by the harder narrow tires. That's also why heart rate data in this case is valuable information. Are we riding faster at a lower heart rate? If so, that could mean we have more energy available to devote to turning over the pedals instead of damping harsh vibrations. This is a hard concept to get your mind around, and I've been thinking about it for many years. I don't have endless resources to set up experiments, but I think this one does illustrate what he is talking about. If the bike industry wasn't so secretive we would all know more. Luckily, the auto industry is required to design tires which provide better rolling resistance due to fuel economy restrictions. I have found lots of information reading peer reviewed scientific papers published by the SAE and the ASCE as well as other reputable European engineering and science journals.There you will find a wealth of information discussing tire construction, rubber compounds, sidewall construction, and so on. You'll find tons of research on various road surfaces, coefficients of friction, and rolling resistance. In Europe tires not only have to meet specific highway standards for grip, and velocity, but for rolling resistance and sound. Yes, sound! They have to be designed so as not to be too loud. The bicycle industry on the other hand doesn't want to share anything. They want you to believe winning races is all the proof you need to buy the next greatest carbon bike. I wish you all the best in your search.

[@NinthwaveThe]

@@Henrywildeberry Maybe it's from you or an audio podcast I listened to but, in risking repeating what you said yourself... In order to make an analogy about the energy lost dampening vibration, one must imagine driving a Jeep at 100 km/h and an E class Mercedes at same speed. In the Jeep, one might believe he is going pretty fast until he takes a look at the speedometer and realizes he is going at a moderate speed. The guy in the Mercedes may believe there is nothing going on as everything is so smooth while he is at 100. In my college years, I did drive an 80s VW Rabbit diesel 4sp standard and I do KNOW that 100 km/h may seem like fast.. All in all, you test may not be perfect but it does bring some usefull data and I like it as usual :-)

[@TomasJ111]

Ron, you need to consider the total diameter: 46mm tyre on a "650b" wheel (584 mm diameter rim) is almost identical to a 26 mm tyre on a "700c" wheel (622 mm diameter).