Long Distance Competition/Ultracycling, Randonneuring and Endurance Cycling - Informal comparison: 23mm v. 28mm tires.

Thorn Cycles Ltd seems to have come to similar conclusions as the BQ report, though there is also little in the way of "Scientific, Lab obtained results"

http://www.thorncycles.co.uk/why26inchwheels.html

The BQ perspective is disturbing, because he dismisses out of hand tests that have been done, and there is zero apparent dialog with those who conducted such tests or have real tire design and engineering expertise. Granted, as an engineer, the test that gets done is often the one that can be done under suitable control. Still, there's no dialog apparent with engineers from Continental, Schwalbe, Panaracer, Vittoria, Challenge, and the others. Jan Heine has presented a radical result (arguable whether the presentation is adequate), and there seems to be no peer review, and noone seems to be researching the discrepancies. What happens if the tires he used are put on the drums? What happens if a drum is textured to mimic road? Can anyone repeat Heine's experiment? Is it even a sound, repeatible methodology? If he extends it to large samples/long duration/naturalistic subjects, what happens? Is there a range of loads and tire pressures for which resistance is minimized? How robust is that advice?

He's bucking a lot of history. Without some of this explored, I don't think it's conclusive at all. It's anecdotal, as evidence of a rolling resistance advantage.

Extraordinary claims require extraordinary evidence. He hasn't shown it.

If you refer to the original article from several years back, you'll note that most of your questions were answered therein. Peer review, independent statistical (regression) analysis, repeated testing, etc.

No one that I know of has paved a drum, but that is hardly Jan's problem. He did some experiments and published his results. If that upsets folks, they are welcome to either poke holes in his methodology or conduct experiments which produce results counter to his. I am not aware of that having been done. Folks who disagree seem limited to "Well, that's not what we've always believed". Testing on smooth drums, if you think about it, really doesn't make much sense. What good is a test that has utterly nothing to do with the use to which the tire will be put? What could be simpler than just testing the performance of tires under realistic conditions, assuming outside factors can be adequately controlled?

Frankly, I don't think his findings are very surprising. As a has-been racer, it is perfectly intuitive that when racing on bad roads you select wider tires. This is not for comfort, as little about racing is comfortable, but about winning. Wider tires are faster on bad roads.

The BQ perspective is disturbing, because he dismisses out of hand tests that have been done, and there is zero apparent dialog with those who conducted such tests or have real tire design and engineering expertise. Granted, as an engineer, the test that gets done is often the one that can be done under suitable control. Still, there's no dialog apparent with engineers from Continental, Schwalbe, Panaracer, Vittoria, Challenge, and the others. Jan Heine has presented a radical result (arguable whether the presentation is adequate), and there seems to be no peer review, and noone seems to be researching the discrepancies. What happens if the tires he used are put on the drums? What happens if a drum is textured to mimic road? Can anyone repeat Heine's experiment? Is it even a sound, repeatible methodology? If he extends it to large samples/long duration/naturalistic subjects, what happens? Is there a range of loads and tire pressures for which resistance is minimized? How robust is that advice?

He's bucking a lot of history. Without some of this explored, I don't think it's conclusive at all. It's anecdotal, as evidence of a rolling resistance advantage.

Extraordinary claims require extraordinary evidence. He hasn't shown it.
There have been few real world rolling resistance tests anywhere. I read about a German test on a rolling drum which doesn't reflect what happens on a road. The BQ study has been torn apart and dissected for the past, I think, 2 years. It has been the subject of lengthy discussions all available through a search engine. It may be seen that engineers from companies have bias as well. Jan Heine doesn't follow the current. At PBP in 07 he rode a (I believe) 73 Alex Singer with a 6 speed freewheel. His bike was much heavier than many Europeans bikes (who were using carbon race bikes) but he was the fastest American finisher. When others challenged his choice of bike as one that would slow him down, he reiterated that the geometry of his steel bike and it's planing characteristics made it quicker and more comfortable. Thus the fastest bike. In 03 he rode a pre 1950 tandem to the fastest coed finish. What is impacting is this article and research, like it or not, has influenced what we ride. People who are riding ultra long rides are using bigger tires and making subjective evaluations that Jan is correct. Of course, not everyone but large numbers ride supple but larger tires for long distance. Most custom steel bikes I would guess are built with larger tires in mind. A friend with a 650B custom will strap on 40's and swears by them.
What do I like? for winter crappy roads I recommend conti 4 season 28's. Of course that is the largest size my bike would take. I love grand bois tires for their subtle feel. If i'm riding an event I would strap them on.

in practice i have found that over ld events comfort plays a key role in maintaining speed. i've moved from 23mm 'race' tires to 28s on my IF rando rig, and occassionally remove the fenders for some 32s, which is as wide as i can go. for me there has been a trend to wider, lower pressure, softer tire as i've gotten into ld events. they haven't slowed me down, but as fitness goes up and changes to the bike happen all at once - it is hard to pinpoint any given variable.

i have yet to try any GB or challenge tires... but friends who ride them swear by them.
we were discussing this not too long ago, and the idea of a short, high powered boat on a rough lake came up as a way to talk tires.

smooth water + short and narrow boat + big engine = fast. rough water + short and narrow boat + big engine means plenty of time bouncing around - with the prop likely bouncing in and out of the water, losing power with every wave.

longer, wider boat with same sized engine will likely perform much better on a choppy lake. the length and width keep it spread over several waves at once, and the prop stays in contact with the water - where it can drive the boat forward...

(*yes, please shoot holes in any theory or discussion i bring, as this was discussed over beers, after a ride)

personal experience and those of my peers - wider + supple casing with lower pressure = more comfort and faster rolling on mixed surfaces.

Thorn Cycles Ltd seems to have come to similar conclusions as the BQ report, though there is also little in the way of "Scientific, Lab obtained results"

http://www.thorncycles.co.uk/why26inchwheels.html
Little as in none. Here's the "conclusion":


(This is a small win for the 26”…let’s just give it 1 point…that’s 3 all…we have a draw!) Well, no actually…the 26 x 1.75” wheel is significantly stronger; it is also significantly more comfortable! As reliability and comfort are fundamental requirements of general touring bikes (well, they are for me…I feel confident in assuming that they are for you too!) then I’d say that this is a clear win for 26 x 1.75” that’s why we prefer 26” wheels for our general touring bikes!

Notice that his comparison ended in a draw, one which he concocted between a 26" and 700c wheel where he also varied tire width, yet he declared the 26" a clear winner. He failed to substantiate in any way that the 26" wheel was stronger, more comfortable, or more reliable yet those are his reasons for breaking the tie. He also gave no consideration to the strengths of the larger diameter wheel because that wouldn't support his prejudice. That's the real similarity with the BQ article.

You can summarize the entire Thorn article by saying that if you ride off-road you should use wider tires. Nothing in the article discussed wheel diameter in any meaningful way despite that being the entire premise of the article. What is interesting to me is that the author thought such a long-winded article was needed to explain something so obvious.

I upgraded from a pair of conti 4000 23's to a set of cheap Bontrager wire bead tires 25 up front and a 28 at the rear ~100psi each. The ride improvement over my commute was profound, smooth and forgiving.

An added benefit was that when I flatted on the rear, it held its structure and allowed me to roll to a smooth stop for repair. Once I got over the feeling I NEEDED 23mm tires to be a real wannabe racer, I cant see ever going back.

There was no significant speed penalty based on my empirical testing as my average speed continues to creep up, mostly based on increasing fitness as others have mentioned.

Frankly, I don't think his findings are very surprising. As a has-been racer, it is perfectly intuitive that when racing on bad roads you select wider tires. This is not for comfort, as little about racing is comfortable, but about winning. Wider tires are faster on bad roads.
Yes, that's intuitive but it's not the point. An article that provides no comparative data is not offering conclusive proof of anything. IF there is a BQ article with comparative data analyzing narrow and wide 700c tires I'd like to see it. The one I read is nothing like that. Do you have a link of something more substantial?

The article appeared in Volume 5, Number 1. The narrowest tire tested was 21 mm and the widest was 37 mm. Among other things, they tested three Michelin "Pro2 Race" tires in different widths: 21, 23.5, and 25.5 mm. The widest was consistently fastest and the narrowest consistently slowest, in terms of rolling resistance.

None of it is "conclusive" but it is certainly the best work I have ever seen on the subject, and I have still not seen any convincing arguments against it.

I run as large a tire as I think my Roubaix will take, and would like something even larger. But for me it's about comfort, as long as speed/effort changes are mostly negligible. But with all the arguments, analysis, and studies proffered here, I can't help but wonder what they do on the Tour. Surely some stages are over rougher roads than others. Do they run wider tires for those? Anyone have a definitive reference/link handy one way or the other? I can assure you that if wider tires were faster (less rolling resistance) in some cases, the pros would be using them. My question is, do they?

The only thing you need to know is that not only does BQ sell Grand Bios tires, they actively collaborate with the manufacture of the tires. Take their "results" with the same grain of salt that you would when Michelin advertises that the Pro Race3 "has the lowest rolling resistance of any racing tire." Why would you believe one over the other???? Not only that but they have you all arguing over an extremely small, almost insignificant difference. If riding on 38mm (any brand) tires was such a great thing every pro team would be on them in a second. I'd be on them in a second!
To sit there as one poster did and imply that what Jan rode at PBP is the optimal ride for PBP is like saying Trek is the optimal ride for road races because "lance" rides on it. Jan is an incredibly talented cyclist but he doesn't walk on water. All Jan's finish at PBP shows is what a good athlete he is and that he will be fast on whatever bike he rides. If you really want to know if his rig is the best have him do it in 2011 on a carbon race bike. As owner of BQ he has an investment in what he rides. Since we are talking about Jan, what about the carbon rice bikes that all the Europeans who finished ahead of Jan were riding? I suppose that they fact that they were probably on 23 or 25mm tires means nothing?

The BQ perspective is disturbing, because he dismisses out of hand tests that have been done, and there is zero apparent dialog with those who conducted such tests or have real tire design and engineering expertise. Granted, as an engineer, the test that gets done is often the one that can be done under suitable control. Still, there's no dialog apparent with engineers from Continental, Schwalbe, Panaracer, Vittoria, Challenge, and the others. Jan Heine has presented a radical result (arguable whether the presentation is adequate), and there seems to be no peer review, and noone seems to be researching the discrepancies. What happens if the tires he used are put on the drums? What happens if a drum is textured to mimic road? Can anyone repeat Heine's experiment? Is it even a sound, repeatible methodology? If he extends it to large samples/long duration/naturalistic subjects, what happens? Is there a range of loads and tire pressures for which resistance is minimized? How robust is that advice?

He's bucking a lot of history. Without some of this explored, I don't think it's conclusive at all. It's anecdotal, as evidence of a rolling resistance advantage.

Extraordinary claims require extraordinary evidence. He hasn't shown it.

I was skeptical at first also, but as I learned about deformation and deflection, it all began to make sense. I have all the proof I need right now, mounted on my '72 Fuji. On the club rides I've been on in 2009 since I mounted the 26mm GBs, I have yet to encounter anyone (save a tandem) who coasts downhill faster than I do. I run up on them, brake to open the distance up, and repeat - and I'm not in an aero tuck. I'm not a flyweight, but there's no shortage of riders who have greater mass than I do, and this happens with them too.

What are they riding? Typically 23's or 21's inflated to higher pressures. I suppose part of the explanation could be my late 70's Sunshine Pro Am hubs, which put their modern Shimano and Campagnolo hubs to shame :innocent: Ok - maybe that's not it, so it would seem to be something besides mass, wind resistance and hub friction. About the only other remaining factor would be rolling resistance. What would you conclude from this evidence?

I was skeptical at first also, but as I learned about deformation and deflection, it all began to make sense. I have all the proof I need right now, mounted on my '72 Fuji. On the club rides I've been on in 2009 since I mounted the 26mm GBs, I have yet to encounter anyone (save a tandem) who coasts downhill faster than I do. I run up on them, brake to open the distance up, and repeat - and I'm not in an aero tuck. I'm not a flyweight, but there's no shortage of riders who have greater mass than I do, and this happens with them too.

What are they riding? Typically 23's or 21's inflated to higher pressures. I suppose part of the explanation could be my late 70's Sunshine Pro Am hubs, which put their modern Shimano and Campagnolo hubs to shame :innocent: Ok - maybe that's not it, so it would seem to be something besides mass, wind resistance and hub friction. About the only other remaining factor would be rolling resistance. What would you conclude from this evidence?

I conclude you went faster than the other guys. The equation has a bunch of terms, andits not easy tojust say the speed was due to your tires - rather, it's too easy. You have an observation. That's not the same as having established the cause.

I was skeptical at first also, but as I learned about deformation and deflection, it all began to make sense. I have all the proof I need right now, mounted on my '72 Fuji. On the club rides I've been on in 2009 since I mounted the 26mm GBs, I have yet to encounter anyone (save a tandem) who coasts downhill faster than I do. I run up on them, brake to open the distance up, and repeat - and I'm not in an aero tuck. I'm not a flyweight, but there's no shortage of riders who have greater mass than I do, and this happens with them too.

What are they riding? Typically 23's or 21's inflated to higher pressures. I suppose part of the explanation could be my late 70's Sunshine Pro Am hubs, which put their modern Shimano and Campagnolo hubs to shame :innocent: Ok - maybe that's not it, so it would seem to be something besides mass, wind resistance and hub friction. About the only other remaining factor would be rolling resistance. What would you conclude from this evidence?
I would conclude that you don't understand the issues as well as you claim and that you have made up some "facts" to suit your preconceived conclusions. Considering that rolling resistance is a minor contributor at speeds typical of downhill coasting, there is important information here that you are excluding if your anecdote is to be believed.

It would be impossible for anyone to coast past me in the manner you describe without being significantly heavier than I am or without having an aero advantage. There simply isn't enough lost in rolling resistance to make that kind of difference, at least according to real tire testing that's been published. Perhaps your tires have a large negative rolling resistance. They are handmade, after all.

Rolling resistance is a function of load and surface conditions. If a tire is large enough for a given load, there isn't a lot to be gained by making it larger but there are aerodynamic losses to be paid for doing so. I don't know why that's hard to understand for some people. They must need to believe in the hype of what they've paid for or what they sell. There's a reason racers use narrow tires and other riders don't. The best choice of tire must consider conditions as well as rider priorities. If a wider tire always beats a narrow one then racers would use wide tires. They aren't that stupid or that inexperienced.


The article appeared in Volume 5, Number 1. The narrowest tire tested was 21 mm and the widest was 37 mm. Among other things, they tested three Michelin "Pro2 Race" tires in different widths: 21, 23.5, and 25.5 mm. The widest was consistently fastest and the narrowest consistently slowest, in terms of rolling resistance.

None of it is "conclusive" but it is certainly the best work I have ever seen on the subject, and I have still not seen any convincing arguments against it.
I have not read Vol 5 No 1, only Vol 6 No 4. The article I read was remarkably uninformative; it was more a marketing puff-piece. I'd like to read the one you reference but it's not online (unless I pay for it I suppose).

It wouldn't be too great a stretch to imagine a 25mm tire outrolling a 21mm one given similar design and a proper load. I don't know the test procedure so I don't know. It would be more surprising to see results ordered by width up and down the line with a 37mm tire being the overall winner. Is that the claim here?

There are other rolling resistance tests that are rigorous and informative. They don't include wider tires but they do include widths in the range used by racers. What you don't see is results ordered by tire width, so I would say that is strong evidence against the claim. In any event, one thing that can be learned from the tests is the magnitude of rolling resistance losses and how they are dwarfed by other considerations at sufficient speeds.

perhaps a good test would be to build a cart (4 wheeled or trike).
mount up the wheels with matching tires.

have a small electric motor with speed governor and a powermeter?
run multiple test uphill, maybe 3% grade at the same electronically controlled speed.
see how much power is required to get the trike up the hill?

then repeat. add weight to the rig, maybe 140 pounds.
adjust inflation for 'tire drop' - come up with some sort of formula / measurement / deflection that you can use on all tests.
run the test again.

then repeat.
add more weight to the rig, maybe 150 pounds.
adjust the inflation as needed.

download all the data. plot the power vs. weight vs. tire size.
we could then talk comparisons.



but, for me, and the folks i ride with, wider is working.
subjectively, maybe.
scientifically, well, i don't have access to world class testing facilities, so, i can't prove it.

If riding on 38mm (any brand) tires was such a great thing every pro team would be on them in a second. I'd be on them in a second!


but you'd have to redesign the bikes, the brakes, potentially use wider rims, etc. etc.
and take it all to the wind tunnel to be sure the aero drag doesn't kill the top speed.

...

It would be impossible for anyone to coast past me in the manner you describe without being significantly heavier than I am or without having an aero advantage. There simply isn't enough lost in rolling resistance to make that kind of difference, at least according to real tire testing that's been published. Perhaps your tires have a large negative rolling resistance. They are handmade, after all.

...

I rather resent the insinuations that I'm not presenting factual information and that I am some unlearned rube who's disposed to falling for snake-oil hype, but I'll set that aside to focus on where I see the disconnects.

Firstly, it isn't merely the width and pressure of the tire that matters. Tread patterns and suppleness of the casing also matter. The former factor should be patently obvious, and the second is admittedly a challenge to wrap one's head around. The deformation is also affected by tire pressure, so yes, there are a number of variables that would need to be controlled for if one was performing a journal-worthy study.

I suspect the large number of variables involved is why the industry has used their drum roller testing technique. Yes, it is scientific, and if one were to ride on surfaces that are as smooth as the drum, the findings would be perfectly valid for transferring results to real world riding. While Jan has neither the time, nor the resources to conduct on the road studies that perfectly control for all the factors involved, his methodology makes a very honest and sensible effort to control for them. His results suggest that, while the differences between the fastest tires are close to negligible, differences between the fastest and the slowest tires are substantial.

Frankly, if I can find a fast tire that's going to also give me a little bit of cushion and comfort, I'd rather ride that than an equally fast tire that's going to have me aware of every bump in the road. I have found tires that do that for me, and they're priced rather moderately. What's not to like?

I rather resent the insinuations that I'm not presenting factual information and that I am some unlearned rube who's disposed to falling for snake-oil hype, but I'll set that aside to focus on where I see the disconnects.

Firstly, it isn't merely the width and pressure of the tire that matters. Tread patterns and suppleness of the casing also matter. The former factor should be patently obvious, and the second is admittedly a challenge to wrap one's head around. The deformation is also affected by tire pressure, so yes, there are a number of variables that would need to be controlled for if one was performing a journal-worthy study. I said that rolling resistance was a function of load and surface, I didn't say that those were the only factors. Tread a carcass design are manufacturer choices. They do not determine best tire width.


I suspect the large number of variables involved is why the industry has used their drum roller testing technique. Yes, it is scientific, and if one were to ride on surfaces that are as smooth as the drum, the findings would be perfectly valid for transferring results to real world riding. While Jan has neither the time, nor the resources to conduct on the road studies that perfectly control for all the factors involved, his methodology makes a very honest and sensible effort to control for them. His results suggest that, while the differences between the fastest tires are close to negligible, differences between the fastest and the slowest tires are substantial.
That methodology is not described in Vol 6 No 4 so who knows what went into that article, but if the results suggest that differences between the fastest tires are "close to negligible" then they refute your claim that it's your tires that make you faster unless you now admit that your riding mates are slow.


Frankly, if I can find a fast tire that's going to also give me a little bit of cushion and comfort, I'd rather ride that than an equally fast tire that's going to have me aware of every bump in the road. I have found tires that do that for me, and they're priced rather moderately. What's not to like?
Nothing not to like except your original claim that your 26mm tires made you faster than everyone else. You did say "I have all the proof I need right now...I have yet to encounter anyone (save a tandem) who coasts downhill faster than I do." If the fastest tires have negligible differences then you have never encountered another rider with fast tires. It may be all the proof you need but it is not proof.

I said that rolling resistance was a function of load and surface, I didn't say that those were the only factors. Tread a carcass design are manufacturer choices. They do not determine best tire width.


That methodology is not described in Vol 6 No 4 so who knows what went into that article, but if the results suggest that differences between the fastest tires are "close to negligible" then they refute your claim that it's your tires that make you faster unless you now admit that your riding mates are slow.


Nothing not to like except your original claim that your 26mm tires made you faster than everyone else. You did say "I have all the proof I need right now...I have yet to encounter anyone (save a tandem) who coasts downhill faster than I do." If the fastest tires have negligible differences then you have never encountered another rider with fast tires. It may be all the proof you need but it is not proof.

I'm not going to type verbatim everything from Vol 5, No 1, since nearly the entire issue was dedicated to the subject. The testing methodology is explained in detail, as are the other, less recognized components of rolling resistance in real world conditions.

Fact - I had the bicycle set up with tubular rims and (nominally 23mm) Vittoria Rally tires. Coasting downhill, the bicycle held it's own with the 10-15 other bicycles in our group on club rides.

Fact - After changing to Sun rims and the GB tires, on the same bike, on group rides of the same or higher category, I found my bicycle outpacing all the other 10-15 bicycles in the same situations.

Fact - My bicycle is about 2 pounds heavier than it was due to the changes in wheels, tires and adding fenders.

Observation - Hey, I'm coasting noticeably faster than I used to, even with wider tires.

Observation - My bike feels a little more comfortable in the new configuration.

My claim is not that there isn't another bicycle anywhere that coasts faster than mine. My claim is not that there are not other tires with lower rolling resistance. My claim is that I have observed the very things that Jan points out.

The width of narrow tires does not automatically make them faster than wider tires.
Running tires at higher pressures does not automatically make them faster.
You can, in a sense, have your cake and eat it too. There is such a thing as fast, comfortable tires, and they tend to be a little larger than the 21's and 23's that a lot of people seem to think you need to have in order to go fast.

Just to throw this in - I've ridden LD with a lot of folks and I've only ever met one person who could coast wheel to wheel with me and one other who was faster (though he uses the center bar hold, which I refuse to use.) I ride 23c. I was once at the bottom of a pass, waiting, when I overheard a couple of newbies saying, "Well, I could coast as fast as he if I had that bike." I had to laugh. I notice no difference w/r to aero bike frame design, or wheel design. It's all about position. I used to race DH on skis. Maybe that's it. Having short legs is a big help, too, as is having an aggressive setup. My BMI is about 25, so I'm not skinny, but not a really heavy guy at 160.

Probably wheels, tires, and frame do make a difference, but it's hard to see in the real world. The biggest difference is how aero can you get and still pedal hard. And of course I'm coasting with guys who all have about the same gear, so my experience is clouded. The guys with the high positions, heavy tires, etc., are so far off the back we don't see them. The really fast guys are up the road, so we don't see them, either, but they all have about the same gear, except for Jan! Jan is fast, but not as fast as some who run conventional equipment: Cervelos and 23c HP tires. So this isn't much help with the tire debate.

Look at FC508 videos and photos. Everyone has pretty much the same gear and position. Brands vary, but it's all about the same. If vintage frames and wide tires were faster because they were more efficient for LD, because they conserved energy or whatever, you can be sure the leaders would be running them.

OTOH, if I were on a 400k course for 25 hours, I'd probably wish I had softer tires, too.

The only thing you need to know is that not only does BQ sell Grand Bios tires, they actively collaborate with the manufacture of the tires. Take their "results" with the same grain of salt that you would when Michelin advertises that the Pro Race3 "has the lowest rolling resistance of any racing tire." Why would you believe one over the other???? Not only that but they have you all arguing over an extremely small, almost insignificant difference. If riding on 38mm (any brand) tires was such a great thing every pro team would be on them in a second. I'd be on them in a second!

If Jan was just making stuff up in order to sell more tires, you'd think he would have avoided telling us that tires by Deda, Michelin, Clement, Continental, Mitsuboshi, Panaracer, Avocet, and Rivendell all ranked better than Grand Bois.

As for what pro teams/508 competitors/PBP fast finishers/etc. use, there are several factors. First, it's worth noting that, within reason, pros ride what their sponsors provide, and few if any makers of truly wide tires sponsor pro bike racers. We do, however, see that on really rough roads, the tires do get wider. 25-27mm is "standard" for classics, cobbled stages, etc.

It's also important to realize that "what everyone is using" is important to racers as well as the rest of us: people looking into the 508 and the like do pay attention to what everyone else is using. If the fast guys are all on Zipps and 23mm clinchers, then the guys who want to try to go fast are all going to be on Zipps and 23mm clinchers. There's no actual information getting into that loop.

And finally, we have to be careful with terms: I don't think anyone is really claiming that wider tires are "faster". The argument is that wider tires have less rolling resistance, which may or may not be the most important factor when selecting tires for any given event. I personally am absolutely sure that my 42mm 650b tires have lower rolling resistance than just about anything I have ridden. They are a wonderful selection for much of the riding I do -- relatively low speeds over relatively rough roads. I would not ever choose them for a criterium or a mountain road race, because the advantage of rolling resistance is completely overwhelmed by other factors, most notably weight.

Overall, I think it's a shame that some of us (no fingers pointed) are so emotionally invested in this truly trivial topic that we are willing to personally attack people who hold different opinions.

If Jan was just making stuff up in order to sell more tires, you'd think he would have avoided telling us that tires by Deda, Michelin, Clement, Continental, Mitsuboshi, Panaracer, Avocet, and Rivendell all ranked better than Grand Bois.

I wasn't implying that he made anything up. I'm implying that he has a bias in his reporting just as Michelin does. Jan has an extremely close relationship with GB providing data and feedback. There is no way he could not have an unbias position. Why should his claim to have lower rolling resistance tires be any more valid that Michelin's? That's all I said, simple as that.


As for what pro teams/508 competitors/PBP fast finishers/etc. use, there are several factors. First, it's worth noting that, within reason, pros ride what their sponsors provide, and few if any makers of truly wide tires sponsor pro bike racers. We do, however, see that on really rough roads, the tires do get wider. 25-27mm is "standard" for classics, cobbled stages, etc.

I've done RAAM three times, competed in the 508 ten times(8finishes), five 1200ks' and a slew of other LD rides/races . I have a pretty good idea what works and what doesn't but like I said before, I'd be on them in a second if they'd give me an advantage. I am (somewhat:))sponsored and occasionally get tires for free and usually run 25's on my Zipp's (even on the tandem). The manufacturers always ask me what size tires I want. I think you'll find that not all the fast long distance guys are on 23's there's probably a fair number of them on 25's as well. From my limited experience, 25mm seems to be the best combination of light weight and comfort for long distance racing/riding.


And finally, we have to be careful with terms: I don't think anyone is really claiming that wider tires are "faster". The argument is that wider tires have less rolling resistance, which may or may not be the most important factor when selecting tires for any given event. I personally am absolutely sure that my 42mm 650b tires have lower rolling resistance than just about anything I have ridden. They are a wonderful selection for much of the riding I do -- relatively low speeds over relatively rough roads. I would not ever choose them for a criterium or a mountain road race, because the advantage of rolling resistance is completely overwhelmed by other factors, most notably weight.
I think we agree here. This is exactly what I was talking about when I said "Not only that but they have you all arguing over an extremely small, almost insignificant difference." People pick up on one insignificant little detail and completely ignore the whole package. It's my opinion that a lot of people use oversized tires to compensate for poorly designed frame/wheel combination's.


Overall, I think it's a shame that some of us (no fingers pointed) are so emotionally invested in this truly trivial topic that we are willing to personally attack people who hold different opinions.

I think we agree here too. ;)

I've done RAAM three times, competed in the 508 ten times(8finishes), five 1200ks' and a slew of other LD rides/races . I have a pretty good idea what works and what doesn't but like I said before, I'd be on them in a second if they'd give me an advantage.


Have you tried them? Maybe the Cerf in a 28? Or step up to something larger like the Cypress in 30??
I think you could do a side by side 'real world' review, unbiased that you are. Would be pretty cool for RAAM go faster racer guy to lay it out.

What says you? Next 400k, 200k, century? Or maybe 1 week on the GBs, next on whatever you normally run?
Of course, your bike might not take wider... which could be another reason your limited to 25s...

Have you tried them? Maybe the Cerf in a 28? Or step up to something larger like the Cypress in 30??
I think you could do a side by side 'real world' review, unbiased that you are. Would be pretty cool for RAAM go faster racer guy to lay it out.

What says you? Next 400k, 200k, century? Or maybe 1 week on the GBs, next on whatever you normally run?
Of course, your bike might not take wider... which could be another reason your limited to 25s...

I have ridden larger tires in the past, I think they were 30's and I don't remember the brand. They weren't bad but they were noticeably heavy. The tire weight is probably much more noticeable on the lighter wheels that I use. I had some 28's put on my single bike during RAAM in 06 because the sponsor threw them in with a bunch of 25's. I believe they were Continental GP's? I didn't even know the mechanic had done that until later I was looking at the tires and thinking they looked awfully big. :) I certainly didn't notice any difference in ride or feel but a jump from 25 to 28 isn't much anyway. Maybe if I was running 23 and jumped to 28's the difference would have been more noticeable.

My current favorite long distance roadbike (a Colnago C-50) nor my current (only) long distance racing tandem (Calfee Dragonfly) will not accept tires larger than 25mm. They rub on the frame. My old Colnago C40HP had no problems with the 28's I talked about earlier. So, I am kind of stuck with my current bike frames. As I said above, the those two bikes are extremely well designed and have an incredible ride, even on stiff Zipp racing wheels and 23mm tires. My assertion is that if you have a well designed bike frame and good compliant wheels you can easily ride 23's and be just as comfy as you would be on a lesser quality frame with heavy 30+mm tires. I can get on either of my bikes and ride a 1200k and finish without feeling like I've been run over by a train, it's awesome. Like everything else in the world there are trade off's and you can't just look at one piece of the puzzle because everything works interdependently. I'll guarantee that if you get the right combination it's pretty awesome!

I wasn't implying that he made anything up. I'm implying that he has a bias in his reporting just as Michelin does. Jan has an extremely close relationship with GB providing data and feedback. There is no way he could not have an unbias position. Why should his claim to have lower rolling resistance tires be any more valid that Michelin's? That's all I said, simple as that.

If Michelin listed half a dozen manufacturers making tires faster than Michelin's, layed out the methodology used for testing, and had their research reviewed by another half a dozen recognized experts on the topic, then I'd be pretty impressed.


I've done RAAM three times, competed in the 508 ten times(8finishes), five 1200ks' and a slew of other LD rides/races . I have a pretty good idea what works and what doesn't but like I said before, I'd be on them in a second if they'd give me an advantage. I am (somewhat:))sponsored and occasionally get tires for free and usually run 25's on my Zipp's (even on the tandem). The manufacturers always ask me what size tires I want. I think you'll find that not all the fast long distance guys are on 23's there's probably a fair number of them on 25's as well. From my limited experience, 25mm seems to be the best combination of light weight and comfort for long distance racing/riding.

But as you've noted, you really don't know whether wider tires would give you an advantage, because you haven't done any real testing with them. You seem to be dismissing them because jan sells them and because nobody else is using them. That's perfectly cool; it's your business, but...


I think we agree here. This is exactly what I was talking about when I said "Not only that but they have you all arguing over an extremely small, almost insignificant difference." People pick up on one insignificant little detail and completely ignore the whole package. It's my opinion that a lot of people use oversized tires to compensate for poorly designed frame/wheel combination's.

If anyone is really claiming that wider tires are faster, I'll disagree with them on general principle. It seems to me that Jan's research is useful primarily in pointing out the fallacy that wide tires are automatically slow and good only for cruising. Very credible performances can and have been turned in on big fat tires, so if someone feels they would benefit from the qualities of wider tires they don't need to worry that their speed will suffer.

...If anyone is really claiming that wider tires are faster, I'll disagree with them on general principle. It seems to me that Jan's research is useful primarily in pointing out the fallacy that wide tires are automatically slow and good only for cruising. Very credible performances can and have been turned in on big fat tires, so if someone feels they would benefit from the qualities of wider tires they don't need to worry that their speed will suffer.

Very well put, IMO. That said, I must say that, as I was driving home from Cirque, (where I purchased my GB in the 26mm size), I was concerned that I had erred, and should have gotten the 28's. Since I've mounted them, and ridden them about, I feel that, if you're riding on pretty well surfaced roads, there's a point at which extra width gains you next to nothing. When I wear down the 26's, I may opt for some 28's, but at this point, it would only be to satisfy curiosity, rather than my feeling the ride is somehow lacking.

I must note though, that these 26 mm tires seem about as wide/tall as Panaracer 28's, and are only slightly smaller than some 35's I have mounted on my winter bike.

If Michelin listed half a dozen manufacturers making tires faster than Michelin's, layed out the methodology used for testing, and had their research reviewed by another half a dozen recognized experts on the topic, then I'd be pretty impressed...You seem to be dismissing them because jan sells them and because nobody else is using them.

Do you know Michelin doesn't? ;) Regardless, my point is that Jan has a personal and financial interest in what he did his research on (which to his credit he acknowledges). If that isn't bias tell me what is? If any other company did that would you accept that research as valid? I wouldn't and don't. It doesn't matter who it is. Nothing against Jan, he's a nice guy. I've had a number of conversations with him but he has a very definite bias, it is what it is. If you want to accept it as valid research, that's up to you.


If anyone is really claiming that wider tires are faster, I'll disagree with them on general principle. It seems to me that Jan's research is useful primarily in pointing out the fallacy that wide tires are automatically slow and good only for cruising. Very credible performances can and have been turned in on big fat tires, so if someone feels they would benefit from the qualities of wider tires they don't need to worry that their speed will suffer.

For the most part I agree, but as you are aware there is more to the equation than just rolling resistance. One example is weight, you still still have a noticeably heavier tire, especially when you get to the much larger sizes. The difference between a 25mm and 28mm tire may be 20-30grams but when you get to the larger sizes like 38mm-40mm+ you've almost doubled the weight of the tire. That can be a significant issue. The bike is going to accelerate and climb slightly slower. It will directly affect speed. The question becomes whether or not it is enough of an issue to be a problem. For a rider like Jan it isn't because he is such a strong rider. For someone barely making the controls it could be a huge problem. It just depends on what you want to do. It is probably the very reason you don't see professional racers on them. One thing about Jan is that he is such a strong rider that he often doesn't understand what goes on at the back of the pack at a ride like PBP. At PBP in 03 I was unfortunate enough to have major mechanical problems that caused me to leave Brest two hours after the control closed. I had the pleasure to ride through all the tailenders on my way back to Paris. It was a very eye opening experience. I told Jan he needs to ride a 1200k at the back of the pack once. I think it would be an eye opening experience for him.

The problem here is that you have people throwing out broad generalizations without taking all things into consideration. 42mm tires may work perfectly for your application with your frame and wheelset but it very well may not for someone else.

I rather resent the insinuations that I'm not presenting factual information and that I am some unlearned rube who's disposed to falling for snake-oil hype, but I'll set that aside to focus on where I see the disconnects.

Firstly, it isn't merely the width and pressure of the tire that matters. Tread patterns and suppleness of the casing also matter. The former factor should be patently obvious, and the second is admittedly a challenge to wrap one's head around. The deformation is also affected by tire pressure, so yes, there are a number of variables that would need to be controlled for if one was performing a journal-worthy study.

I suspect the large number of variables involved is why the industry has used their drum roller testing technique. Yes, it is scientific, and if one were to ride on surfaces that are as smooth as the drum, the findings would be perfectly valid for transferring results to real world riding. While Jan has neither the time, nor the resources to conduct on the road studies that perfectly control for all the factors involved, his methodology makes a very honest and sensible effort to control for them. His results suggest that, while the differences between the fastest tires are close to negligible, differences between the fastest and the slowest tires are substantial.

Frankly, if I can find a fast tire that's going to also give me a little bit of cushion and comfort, I'd rather ride that than an equally fast tire that's going to have me aware of every bump in the road. I have found tires that do that for me, and they're priced rather moderately. What's not to like?

I accept that you had a result that you reported accurately. I think one possible cause for you coasting past other riders is that you actually stopped pedaling when you were already going faster than the other riders. It's also just one example of factors that should be controlled in field tests, that might be hard to control in an impromptu observation.

Many tests that engineers do are intended to measure product behavior, but in a way that selected factors are isolated. Generally it would be wrong to interpret the result of such tests as representative of real-world, combined-factors operation. It could be that the result of such an engineering test does represent field performance in some limited use cases, but I'm not a tire engineer, and couldn't say what limited applicability drum tests have, if any.

I think this is why you and others call drum tests "scientific." For a test to be "scientific" does not affect its usefulness in engineering. What does affect usefulness is an established methodology, a focused purpose, general acceptance within the user community (perhaps there's an ISO or SAE standard that defines the test), and the capability of the test to provide accurate and repeatible data when conducted properly. If I was a tire test or competitive analysis engineer, I would need to know that if I have tested 100 tire products, 30 samples each over the past 10 years, and I receive 10 more tire products to test and compare to the previous results, that I have a procedure and apparatus that will produce new data that is comparable to the old data. The economics and time commitment of conducting the test are also critical.

Within a company such high quality data allows the company to compare current product with competitive current products, to track the progress of other companies as they make improvements, and to track improvements in current products. The decision to "ship it" needs to be based on knowing when a product improvement is good enough to put on the market, leaving other possible improvements for the next market cycle. Naturally all such test results and conclusions drawn from them are corporate secrets, highly confidential proprietary information. I absolutely do not expect Michelin, for example to open up and share such information. When I worked for Ford we would never have done so. Any technical papers or other disclosures are carefully reviewed.

Often academia will be involved in creating and validating such tests, and might employ them for their own research purposes. It's important that the customers for their research results, practicing engineers in corporations, can evaluate technology improvements in light of how they test in their jobs.

Anyway, this is just some of the need for tests such as the drum test, that are limited but dependable. I find it hard to believe Jan's tests are similarly dependable, but that's really just speculation, and I feel safe in expecting that nobody has attempted to explore this to the scale that a corporation would need to.

FWIW, I'm an avid reader of BQ, but a middling long-distance rider (Centuries, etc.), certainly not of the experience of most of you.

But what *I* have taken away from reading Jan Heine's (many) tests over time is:

- He really tries, in a low-cost way, to set up tests in real world conditions that are repeatable and verifiable. He publishes exactly how he does the tire tests, and anybody else who wants to repeat them is free to get a bunch of tires, tubes and bikes and go out and try to come up with different results. (My own personal observation is that a lot more energy has been expended trying to argue against the BQ tests than repeat them).

- Partly what he is trying to do (in my opinion) is to slay the myth that narrow tires, that need to be ridden at higher pressures, are always going to be faster. He's also trying to show that there is a very wide variance in performance in tires of similar width. Therefore, if narrower tires aren't always faster, and wide tires aren't demonstrably slower, why not consider a wider tire for other benefits it brings?

- If you can then let go of the idea that narrower tires are *always* faster, you can then find yourself riding bigger tires that allow for lower pressures, more comfort on bad road surfaces, and the ability to ride on worse surfaces and even dirt/gravel roads.

The end result is that long-distance cyclist ends up riding "faster" over a very long distance, partly because of additional comfort and the need to spend less time off the bike resting, or that a cyclist can explore routes that aren't possible on narrower tires.

My personal takeaway was really simple - I switched to 28c's mainly to increase comfort on chipseal roads. If it weren't for BQ tests I'd be agonizing over the speed loss. I think the BQ tests have simply informed me that I have much bigger things to worry about (like the inherent weakness of the engine).

Benge Boy you are right that comfort is paramount on long distance events. You can't go fast if you aren't comfotable. Ask any ultra-distance racer. 99% of RAAM racers are on high end carbon framed bikes with 25mm tires or smaller for a reason. Because they are light, efficient and above all comfortable. Does that mean you should be on a high end carbon framed bike for a 1200k brevet? No, it doesn't. What it shows is that you can be extremely comfotable on a wide range of platforms.

What people are missing is that it isn't just a tire issue. You have to look at the whole package. The frame design matters, the wheels matter, handlebars, seats, rider strength, everything matters. When you have a well designed package you don't necessarily need to put a bigger(ie heavier) tire on there to be comfortable over long distances. On long rides and races small things add up, especially for the weaker riders. 5lbs on your bike may only add a couple hours to a 1200k brevet but if you are barely making control times that could be the difference between finishing and DNFing.

I accept that you had a result that you reported accurately. I think one possible cause for you coasting past other riders is that you actually stopped pedaling when you were already going faster than the other riders. It's also just one example of factors that should be controlled in field tests, that might be hard to control in an impromptu observation.
...

I was careful about that as well. On several of those occasions, I've had to apply the brakes - had the riders gain a bit of distance, and then continued the coast, only to again gain ground and having to repeat this (I described this, though evidently not in sufficient detail). No matter though. I'm not, and don't expect I'll become a racer, so even if there is something that's a little bit lighter and also fast, it probably won't displace these on my designated randonneuring bicycle.

When you have a well designed package you don't necessarily need to put a bigger(ie heavier) tire on there


I totally agree with you on having the whole package dialed in... but I just don't get the weight argument. Lets look at some numbers: (and this is not a complete list, but something I pulled from an online shop I've frequently ordered tires from - all sizes and weights are pulled from the online retailer)

Michelin Pro3 Race TS - 200 grams (8.69 grams per mm width)

Conti GP4000 S 23mm - 205 grams (8.91 grams per mm width)

Conti Gatorskin 25mm - 250 grams (10 grams per mm width)

Conti GP 4 Seasons 25mm - 250 grams (10 grams per mm width)

Vittoria Open Corsa EVO 23mm - 235 grams (10.2 grams per mm width)

Vittoria Open Pave EVO GC 24mm - 260 grams (10.8 grams per mm width)

Panaracer RIMBO 25mm - 370 grams (14.8 grams per mm width)

Schwalbe Stelvio HS 25mm - 255 grams (10.2 grams per mm width)

Schwalbe Ultremo 23mm - 195 grams (8.47 grams per mm width)

GB Cerf 26mm - 220 grams (8.46 grams per mm width)

GB Cerf 28mm - 248 grams (8.85 grams per mm width)

GB Cypress 30mm - 290 grams (9.66 grams per mm width)

Looking at volume of air carried disregarding pressure, and assume noominal sizes so circumference = (622 +(TireWidthx2)) x pi

23mm tire = 415.8 sq mm x 2098.58 = 870,919 cu mm = 53.1467382 cu inches
25mm tire = 490.88 sq mm x 2111.15 = 1,036,321 cu mm = 63.2401875 cu inches
26mm tire = 530.92 sq mm x 2117.43 = 1,124,188 cu mm = 68.6021608 cu inches
28 mm tire = 615.75 sq mm x 2130 = 1,311,548 cu mm = 80.0355695 cu inches
30 mm tire = 706.85 sq mm x 2142.56 = 1,518,754 cu mm = 92.6800554 cu inches

So...

Michelin Pro3 Race TS 23mm = 200 grams or 3.76 grams per cu in of air

Conti GP 4000 23mm = 205 grams or 3.85 grams per cu in of air

Conti Gatorskin 25mm = 250 grams or 3.95 grams per cu in of air

Conti GP 4 Season 25mm = 250 grams or 3.95 grams per cu in of air

Schwalbe Ultremo 23mm = 195 grams or 3.67 grams per cu in of air

GB Cerf 26mm = 220 grams or 3.20 grams per cu in of air

GB Cerf 28mm = 248 grams or 3.09 grams per cu in of air

GB Cypress 30mm = 290 grams or 3.12 grams per cu in of air


Seems like the GB Cerf 28s are a the best balance of weight per volume of air carried.
And if they have an as advertised benefit of supple casing, high thread count, and low rolling resistance on a drum and on anecdotal evidece from 'roll down' real world tests... seems like getting more air under me, at a slightly lower pressure, is a winner for long distance events... especially over rough surfaces. And assuming that they hold up to the surface and hazards that I might encounter.

So, I don't buy the weight argument, especially as most LD events are not races where acceleration up a climb or out of corners is critical.






And, as to 'high end carbon bikes' - my guess is that unless it was specifically designed for rando or wider tires, you are stuck with 25mm max (unless it is a cross bike...)

I had a custom Ti bike built as I was frustrated with my stock LeMond. I could get 25s in there - but 28s would leave me with 1mm each side to the chainstay - too close for comfort if I had a mechanical that knocked the wheel out of true.


And note, I don't own GB tires. I've been rolling on GP 4 Seasons for 3 years with good luck, and just when I was about to order up some GB Cerf 28s a friend dropped another pair of GP 4 seasons on me - so the GBs will have to wait until next year.

^^ That's certainly a new way of looking at things. Thank you for the perspective.

I totally agree with you on having the whole package dialed in... but I just don't get the weight argument. Lets look at some numbers:

GB Cerf 28mm = 248 grams or 3.09 grams per cu in of air



Seems like the GB Cerf 28s are a the best balance of weight per volume of air carried.
And if they have an as advertised benefit of supple casing, high thread count, and low rolling resistance on a drum and on anecdotal evidece from 'roll down' real world tests... seems like getting more air under me, at a slightly lower pressure, is a winner for long distance events... especially over rough surfaces. And assuming that they hold up to the surface and hazards that I might encounter.


I'll just add one in:

Vittoria Rubino Pro 3 28mm = 245 grams.

No, Jan Heine's results are actually nothing new. Here is for example a translation of a test in German magazine "tour" (page 3-4; could be that the translation was paid for by Continental).

http://www.conti-online.com/generator/www/de/en/continental/bicycle/general/downloads/download/tourtest_gp4000s_en.pdf

The supposedly larger rolling resistance of wider tires is just one of the old wives' tales that are permanently repeated. We had a long discussion about it here on the clydesdales forum if I remember, with lots of engineers explanations.



The BQ perspective is disturbing, because he dismisses out of hand tests that have been done, and there is zero apparent dialog with those who conducted such tests or have real tire design and engineering expertise. Granted, as an engineer, the test that gets done is often the one that can be done under suitable control. Still, there's no dialog apparent with engineers from Continental, Schwalbe, Panaracer, Vittoria, Challenge, and the others. Jan Heine has presented a radical result (arguable whether the presentation is adequate), and there seems to be no peer review, and noone seems to be researching the discrepancies. What happens if the tires he used are put on the drums? What happens if a drum is textured to mimic road? Can anyone repeat Heine's experiment? Is it even a sound, repeatible methodology? If he extends it to large samples/long duration/naturalistic subjects, what happens? Is there a range of loads and tire pressures for which resistance is minimized? How robust is that advice?

He's bucking a lot of history. Without some of this explored, I don't think it's conclusive at all. It's anecdotal, as evidence of a rolling resistance advantage.

Extraordinary claims require extraordinary evidence. He hasn't shown it.

^^ That's certainly a new way of looking at things. Thank you for the perspective.

Thanks. That Vittoria in 28 looks interesting.
Also note that in my experience most 'road' tires run smaller than advertised - my '28s' are running 26 or so (yes, rim choice makes a diff...) - but the GBs are listed as being a bit wider than spec'd - which skews those numbers a bit.




I read that TOUR article linked below and will have to get those 4 seasons off my bike come spring! Even on a drum they have high RR.!

Here is an updated list: (and still partial list)

http://lh6.ggpht.com/_0jkA5M3PGcY/SwGA7dpzzsI/AAAAAAAAOCg/w7bhe7QSDPs/s800/tiredata.jpg

I've added $ per Cu In along with the Weight per Cu In of Volume.

The Pasela looks like a smoking deal... ;)
I'll have to look for data for the narrow varieties of that tire.

Now, to cross reference with drum tests and to come up with some sort of ranking. ;)

I was careful about that as well. On several of those occasions, I've had to apply the brakes - had the riders gain a bit of distance, and then continued the coast, only to again gain ground and having to repeat this (I described this, though evidently not in sufficient detail). No matter though. I'm not, and don't expect I'll become a racer, so even if there is something that's a little bit lighter and also fast, it probably won't displace these on my designated randonneuring bicycle.

Obviously I don't have a complete answer!

Obviously I don't have a complete answer!

I don't think anyone has all the pieces yet. :o

I must note though, that these 26 mm tires seem about as wide/tall as Panaracer 28's, and are only slightly smaller than some 35's I have mounted on my winter bike.

Interesting. What type of rim do you have them mounted on? I have 26mm GB Cerfs on Velocity Aerohead rims (20mm wide) and they measure out true to size. Compare that to my other road bike using the 25mm Gatorskins mounted on Velocity Fusion rims (19mm wide) and they measure out to 26mm. Both tires are run at 95 psi. The Cerfs are superior in comfort and speed. As you had said earlier, I too have found myself coasting along on club rides and overtaking others.