Thanks for the info you've posted on this subject previously. Have your tests compared latex v. butyl tubes? Is there much difference?

Thanks. HH

PS: I've pretty much decided to get rid of my tubular race wheels and get clinchers.

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It doesn't really matter what Phil is saying, the music of his voice is the appropriate soundtrack for a bicycle race. HTupolev

"You won't be doing any course where the weight penalty of a disk outweighs the aero benefit."

Ken,

I did a Oly race last year on a course that featured lots of rolling hills, but also a number of very sharp, steep hills with very fast, twisting descents coming down the back sides of those hills. I hadn't ridden a disk before last year and I really didn't like the handling of my Renn 575/HED Alps (650 tubies) in corners and sharp curves. I previewed that course and decided I'd attack the course with more confidence on wheels I had more miles/experience on. I ended up riding my Bontrager Race Aero clinchers (basically my training wheels) with Vittoria Corsa Evo CX tires to the second fastest bike split of the day ... my best result. I was very happy with my choice that day.

I'm just curious how you've found the handling of your disk to be on more technical courses.

BTW, the fastest split was Peter Kotland (Kortland? Cortland?) and I don't recall if he was on a disk or not.

Bob C.

I ride my "disk" all the time in training (it's a PT/Open pro with a homemade cover), with no issues. I've done some courses with hairy turns (ask armytriguy about the Lighter Than Air duathlon bike course) that I've taken at higher speed than was safe. I did a bike route I love (52 miles, ~6600' climbing in 14 climbs nearing 20% in places) with this wheel and set a PR (normalized power of 273W over 3:20!). I don't know if there's anything about a "real" disk that would be different. Stiffness?

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"Go yell at an M&M"

Ken, I'm not too sure we are comparing apples to apples here. A spoked wheel with a cover handles like a spoked wheel, with a cover. I have several discs and they do feel different compared to each other, but handle tight corners a lot scarier than most spoked wheels will. Some of the low spoke count carbon rims are on the other end of the spectrum with me as they are too flexy and can get scary too, where the disc is so stiff it trys to skip instead of flexing.

When people tell me that their disc seems scary on technical courses, I believe them 100%. That may be another selling point for wheel covers as an open Pro 32 hole rim 3 crossed with a cover is a very nice riding wheel . Also lowering the air pressure to 100-120 ish will take some of the bad manners out of disc wheels.

I think some posters replies to the re-posting of some things I have said seem to believe that we have some secret reason for advocating tubulars or are trying to pull the wool over everybody's eyes on this tubular/clincher debate. Since we make and sell all of our products in both, we certainly could care less what you buy or use, but saying that clinchers are better due to lower RR in one specific type of test if underestimating things a bit, sort of like the Triathlon Germany wheel aerodynamic testing on the indoor velodrome, these tests do conclusively show superiority in this particular test scenario, but from the testing I have been privy to and worked with there are many real world situations where the tubular will have equal or lower RR, specifically poor road surfaces. Having said that, even if clinchers can surpass tubulars in all RR situations tubulars will continue to be most prevalent in pro road racing due to the safety issues and ability to ride when flat, as well as the weight discrepancy which will remain indefinitely due to the necessary design limitations of clincher rims.

Also somewhere it was said that clinchers were an aerodynamic mess. They are not a mess, they are just different than tubulars, so that using the same rim shape for both will leave one of the products lacking when compared. This forces us to design the clincher and tubular versions of a rim as two different products, so that they share rim depth and marketing but from engineerings point of view they are totally different products. All of our clincher products more or less mimic the performance of the tubulars with the 404 clinchers having a slight advantage actually over the tubies and the 808 tubulars having a slight advantage over the clinchers. To give you an idea of how different things are, however, here is a photo of our new clincher disc (shipping in a few months). We really had to work some sidewall curvature into the shape to clean up the airflow off of the tire, and blend the aluminum to carbon interface so as not to have a hard lip between the two as that lip can cause 3-4 watts of drag in some designs. But you can see that the final product essentially looks nothing like our tubular disc, yet the performance is nearly identical.

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http://www.SILCA.cc
Check out my podcast, inside stories from more than 20 years of product and tech innovation from inside the Pro Peloton and Pro Triathlon worlds!
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"I have several discs and they do feel different compared to each other, but handle tight corners a lot scarier than most spoked wheels will ... the disc is so stiff it trys to skip instead of flexing."



What he said.

[quote]but from the testing I have been privy to and worked with there are many real world situations where the tubular will have equal or lower RR, specifically poor road surfaces.[/quote]

As a former co-worker would always tell me: "Show me the data!"

At the least, can you (or anyone, for that matter) put for a plausible hypothesis of why a tubular would suddenly have lower RR on the road. To my knowledge, the only situation where tubulars have an advantage RR-wise is on a smooth track...and that's only because you can pump the snot out of the pressure high enough to overcome the inherent losses.


[quote]Having said that, even if clinchers can surpass tubulars in all RR situations tubulars will continue to be most prevalent in pro road racing due to the safety issues and ability to ride when flat, as well as the weight discrepancy which will remain indefinitely due to the necessary design limitations of clincher rims.[/quote]

That's a fallacy...in fact, just recently I witnessed someone riding (safely) 2 miles down an twisty 8% grade and then ~4 miles along the flats (at speeds up to 20mph) on a flatted FRONT clincher. Granted, some combinations of rims and tires are more secure than others, but getting a flat with a clincher doesn't necessarily result in an instant "yard sale" like most believe.

Also, weight isn't the issue everyone thinks it is. In fact, do you recall why Ivan Basso used heavier 404 rims (instead of lighter 303s or 202s?) on the Alp'd Huez TT 2 years ago?

Oh yeah...I've run the numbers of tubular vs. clincher on climbs. Using identical wheels (Zipp 404 and Vittoria Corsas) it takes up to an 8% grade for the ~1lb weight advantage of the tubular combination to make up for the disadvantage in RR. At all grades below that, the heavier clincher version is ahead.

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http://bikeblather.blogspot.com/

[quote] think some posters replies to the re-posting of some things I have said seem to believe that we have some secret reason for advocating tubulars or are trying to pull the wool over everybody's eyes on this tubular/clincher debate. Since we make and sell all of our products in both, we certainly could care less what you buy or use,...

...Also somewhere it was said that clinchers were an aerodynamic mess. They are not a mess, they are just different than tubulars, so that using the same rim shape for both will leave one of the products lacking when compared. This forces us to design the clincher and tubular versions of a rim as two different products, so that they share rim depth and marketing but from engineerings point of view they are totally different products. All of our clincher products more or less mimic the performance of the tubulars with the 404 clinchers having a slight advantage actually over the tubies and the 808 tubulars having a slight advantage over the clinchers. To give you an idea of how different things are, however, here is a photo of our new clincher disc (shipping in a few months). We really had to work some sidewall curvature into the shape to clean up the airflow off of the tire, and blend the aluminum to carbon interface so as not to have a hard lip between the two as that lip can cause 3-4 watts of drag in some designs. But you can see that the final product essentially looks nothing like our tubular disc, yet the performance is nearly identical.
[/quote]

I almost forgot...is the price for this clincher version higher, lower, or the same as the equivalent performing tubular disc?

If it's the same...how do you recoup the extra development cost and the higher manufacturing costs due to extra steps and part required? Just curious ;-)

I'm not saying there is any intentionl misleading going on...I'm just pointing out that there could be at least a subconcious monetary incentive to favor, or at the very least, not give up so easily on, tubular wheels.

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http://bikeblather.blogspot.com/

"That's a fallacy...in fact, just recently I witnessed someone riding (safely) 2 miles down an twisty 8% grade and then ~4 miles along the flats (at speeds up to 20mph) on a flatted FRONT clincher. Granted, some combinations of rims and tires are more secure than others, but getting a flat with a clincher doesn't necessarily result in an instant "yard sale" like most believe. "


I don't think that is a lot of data. One guy does it for you ? a clincher rim is safer then a tubular rim with a flat ? I would rather be on tubbies in that situation. I know it is just me and I ain't the brightest bulb in the box but just look at the shape of the rims. I have had this happen with both rims.

I think you are getting clincher madness. ; -)


Thom

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Slowtwitch bitchist place on planet earth

[quote]a clincher rim is safer then a tubular rim with a flat ?[/quote]

I never said that.

Besides, the example I gave may be just an n=1 experiment, but isn't that all you need to disprove the notion that tubulars are ALWAYS safer to ride flat? The way I've always seen it stated, once you flat a clincher you have to immediately stop or you'll instantly eat pavement...it just ain't so.


[quote]I think you are getting clincher madness. ; -) [/quote]

I think I'd rather have "Reefer Madness" :-)

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http://bikeblather.blogspot.com/

By me, a flat on the front clincher means stop, or either roll the tire off the rim and risk damage to the rim,fork and rider. At best riding on the rear rim on a clincher means a lot of wear on the rim or possibly trashing it all together. I have ridden 4 miles in a flat TT on a rear sewup with no visibal damage to the rim. I have limped to the pit, but riding on flat fronts with sewups. in a crit or two . In a cross race a have ridden almost a lap with a flat front tire. I know I would have been walking with a clincher in that instance. I personally think in a crit it is faster and safer to run to the pit than ride a flat front clincher. In a Triathlon I guess it a judgement call on how far out to change a tire or ride in. Again I think the advantage is to a sewup as to how far out I would ride into the transition from a flat.

No, I did everything with normal thick butyl training tubes in the clinchers. Don't know much about latex tubes. Only what I've read.

Tom,

I think you misunderstand the economics of a disc wheel. A tubular disc is very expensive as we have to essentially make a superlight carbon rim and then construct that into a disc. With the clincher disc we have to do the same thing with an aluminum clincher rim which is cheaper than a carbon rim, but then it has to be constructed into a disc as well, so the costs really aren't all that different. The development costs aren't really that different either as you are assuming that the tubular development was fast and easy, it wasn't. Since the cost of the development of the dimpled composite process is attached to the tubular disc, the clincher disc could use considerable resources and wind tunnel time in development before getting close to the cost of the tubular disc development. All in all it took us some 2 years to develop and refine this clincher disc concept into something that worked as well as it does, but then again it took us nearly 3 years to determine the most effective dimple pattern, dimple shape, dimple depth, etc.. then determine how to actually do the dimpled composite molding, and lastly how to construct the tooling since nobody had ever done it before, plus we filed patents for all of this which is very expensive.

The thing I don't see here is how or why anybody would think I have some vested interest in selling tubulars to everybody...we sell clinchers and tubulars for the same price because the manufactured costs are very similar (tubies have more carbon in them, so more labor in the layup process as well as more expensive materials, the clinchers use less carbon but the aluminum hoop does have to be completely prepped for bonding and post machined, both processes which add considerable labor cost so it is really a wash), so a wheelset is a wheelset as far as that goes, I'm just here relating some things I've seen and experienced in this business that may help some folks out instead of just confusing them with marketing gobledygook that some sales guy came up with.

The theory on why a tubular has less RR than a clincher on rougher pavement from what I have discussed with this tire manufacturer is that the tubular carcass can better distribute the displacement of a small impact over a larger portion of tire carcass with less localized deformation and lower localized shear forces in the tire tread or casing. I really can't print or publish data that isn't mine, the test I saw was done by a very major tire manufacturer and I was fortunate enough to be involved, but that surely won't happen again if I go around publishing data I didn't pay for on the internet. The real point is probably that the test I took part in utilized a rough surface and the Tour test utilized a machined drum, these are totally different tests with very different outcomes...

As for Basso on Alpe d'Huez, I was actually there that day with the team and we had actually calculated that Z3's would be fastest due to the weight/aero balance of that wheelset, but a difference in scale calibration left Basso's bike too light with Z3's when the UCI weighed it and with only a few minutes to his start time the easiest way to add weight was to change the wheelset. That bike already had some 340 grams of chain dropped down the seat tube as ballast, and the bike did weigh 6.8 kilos according to the CSC scale, but not the UCI, so the wheel choice had nothing to do with anything other than meeting the 6.8k limit.

cheers

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http://www.SILCA.cc
Check out my podcast, inside stories from more than 20 years of product and tech innovation from inside the Pro Peloton and Pro Triathlon worlds!
http://www.marginalgainspodcast.cc

Thanks for your contributions to this thread (and this forum, for that matter), Josh. I'm sure I speak for more than just myself when I say that I appreciate all the insight and experience you contribute.

Love the first-hand Basso story.

Bob C.

There is one negative about tubulars that is relevant to most ST readers--- If you race in a triathlon with tubulars, you have to carry one or two tubular spares. These are whole 250+ gram tires versus just carrying 50 gram inner-tubes. Besides adding up to a pound of extra weight, they take up a large volume so both disturb aerodynamics and take up space that could be used for other things like water bottles. I see guys who paid for dimples on their wheels and carbon handlebars with spare tubulars flapping in the breeze.

For Ironman Canada, I tried to clean up my bike aerodynamics by putting my tubular and toolkit in a bottle in my bottle cage--- That solved aerodynamics, but when I dropped my bag of gels I really missed the extra calories I would otherwise have had in that bottle. I know there are other solutions for carrying spare tubies but nothing beats not having to carry those big spare tires in the first place.

I have tubulars and have raced on them for 25 years, but if my race wheels weren't in perfect condtion I would switch over to clinchers just to get rid of that spare tubular I have to pack for races.

As far as road racing goes, tubulars are my strong preference--- They give a noticably improved ride and handling and spare wheels are carried in the support vehicles.

-Marc

[quote]I think you misunderstand the economics of a disc wheel...snip[/quote]

Thank you for answering my question! It's great that it works out for you that "a disc is a disc".


[quote]The theory on why a tubular has less RR than a clincher on rougher pavement from what I have discussed with this tire manufacturer is that the tubular carcass can better distribute the displacement of a small impact over a larger portion of tire carcass with less localized deformation and lower localized shear forces in the tire tread or casing.[/quote]

If that's the case, why isn't that also true for the contact patch deformations on a smooth drum? Deformations are deformations...


[quote]The real point is probably that the test I took part in utilized a rough surface and the Tour test utilized a machined drum, these are totally different tests with very different outcomes...
[/quote]

But, that test doesn't match the data from either the smooth drum testing OR field testing on real world roads. Coupled with the lack of a reasonable theory about why this should be, I think I'd be questioning the results of that particular test.


[quote]As for Basso on Alpe d'Huez, I was actually there that day...so the wheel choice had nothing to do with anything other than meeting the 6.8k limit.
[/quote]

That's exactly the story I had heard. The point I was making was that bikes and components are so light as it is, the fact that a 404 is heavier than a 303 didn't mean anything...you could take the better aerodynamics of the 404 and still be under the weight limit.

You guys should've ditched the 340 grams of chain and set Ivan up with a pair of clincher 404s...he would've been smokin'!!! :-)

Then again, he probably had Dugast silks epoxied onto those tubies anyway, huh? ;-)

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http://bikeblather.blogspot.com/

I think that the difference in displacements is that the smooth drum test is essentially modelling a steady state contact patch at only one tire deflection, a deflection which is relatively small. On rough roads, the contact patch is constantly changing shape due to road surface so the tire is deflecting in various ways which range from less than to more than that seen on the drum. The closest real world testing to this I have seen was at Tour of Georgia where we sent a bunch of clincher wheels to the team so that they wouldn't have to bring so many wheels from Europe. We were interested in seeing how wheel weight affected power on rolling terrain (especially with more than one company touting 'better rolling' with heavier aero wheels). On mildly rolling terrain, we really couldn't see any difference between the two taken as an average over time, but maybe the better RR of the clincher wheels was offsetting the weight penalty :-)

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http://www.SILCA.cc
Check out my podcast, inside stories from more than 20 years of product and tech innovation from inside the Pro Peloton and Pro Triathlon worlds!
http://www.marginalgainspodcast.cc

 >>I get 5000+ miles out of Pro/Pro Race/Pro Race 2.

I get about 400-500 miles if I run a Pro Race 2 on the rear at which point it is usually cut up so bad I would be too nervous to rotate the tire or continue to ride it as a rear tire. Handles well, wears poorly. I have no idea how to get 5000 miles on a Pro Race2 short of staying on the track the entire time, then maybe.

Thats been my experience as well...great tires but I can only use them for racing (use gp3000s for training). Of course, my Tufos that I trained on once in a while didn't even last that long.

ot

Same here. I rode mine for about 2000km and when I put the bike on the trainer for my winter training I noticed the front tire was all cut up.

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Searching for the bliss of ultimate exertion.

I guess this is a little apples and oranges. I don't race the tire at 5000 miles. Just a few hundred miles and the tire becomes a training tire. I also never use a Pro XXX on a trainer as a rear tire, which means after the tire is relegated to training it sees most of it's time on the front.

The point still remains. There is no reason to chose a Michelin Carbon for longevity since the Pro lasts long enough as a race tire and makes a better race tire. One logical choice would be to train on Carbons and race only on Pro's, but if I were to do that there are even cheaper, and more durable tires to use for training than the Carbon. And that is the point I was trying to make.

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Justin in Austin, get it? :)

Cool races:
- Redman
- Desoto American Triple T

I can't believe I just read this whole thread. I've got to get out of this place... I'm going to swim.

Very good point, what negative aero effect is created by the extra tubulars.

How many spares to most people carry, weight?

How much drag? Tubular spares vs $$ spent on dimples, carbon, etc.

Clinchers w/ 2 spare tubes & air vs Tubular w/ 2 tubulars & air: Compare Weight/Drag

Who wins?

Put a blue hub on it and I'll buy one, Great looking wheel

You needed to run them in a race to see how wheel weight affected power, and you expected to be able to ascribe any differences to tubular vs. clincher? That's pretty surprising.

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"Go yell at an M&M"