And these teams would mount their clinchers on which TT wheels exactly?
I have written on this subject several times. There is no good test of the difference between tubulars and clinchers. The resistance data compares tubulars at low psi 120, no one I know rides tubulars at that low a psi. The aero advantage of tubulars was not looked at except for one article which is posted on wattage and here.
We need someone who has access to 2 sets of wheel exactly the same one in clincher and one in tubular. Test with a power meter at speeds between 40-50km/h using a thin tubular 20-21mm with appropriate thin frame at different psi ei 140-220 versus a clincher at 120psi on same wheelset. Then we will have the answer.
I suspect the pro teams have done this but don’t want to share the data so that they don’t offend sponsors. The best example is the team using tubulars being sponsored my Michelin. I find it hard to believe that clinchers are better in a TT as the Michelin teams should have used their Race2 Pros and won with all the other teams using tubulars. I can’t believe they don’t know this and in a sport where a few seconds matter they would go to great lengths to switch to tires not made by their sponsors when everyone on this forum believes that the Michelin clinchers are the fastest. Do they know something we don’t ? Why hasn’t anyone tried a clincher in a TT or in the flat part of the race for that matter.
You’re making the assumptions that:
- Higher tire pressure on a normal road surface results in a lower resistance to forward motion.
- Tubulars have an aerodynamic “advantage” of some sort.
- Pro teams and riders are somewhat “tech savvy”.
- Nobody rides clinchers at the pro level, not even for time trials.
Please post evidence that any of the above assumptions are true…especially since there’s evidence out there that the opposite of those assumptions is true.
Thanks.
Eddie with a fag in his mouth? Wonder what the brits and aussies on this forum think about this…
just confirms what we think about you euros…
Look up the wattage forum on google groups under Tufo tire slam for the relevant articles that point to the assumption that higher psi produces lower resitance. I haven’t seen any other study disproving this point, all the studies so far have done tire testing at 120psi.
There was an article again on that forum that showed that a 19mm tire has a 15watt advantage over 21 or 22mm tire due to aerodynamics at 50km/h.
I don’t understand your last point since it proves my point that if they don’t ride clinchers at the pro level there must be a reason for it. Lance spent hours in the wind tunnel testing position, wheel and even clothing. This was a special section on Versus prior to the 05 Tour. I doubt he would waste his time looking for a 1-2 sec advantage in clothing when there was a 30 sec advantage by using clinchers as some here claim by looking at the resistance data.
I suggest you look at zip.com and see that there is a disk and a deep front wheel set same as the ones used by Fabian for sale. Why don’t they get the faster clincher set when they can get whatever set they want ?
Not sure your point exactly but… I would think its along the same lines as Kenyan Runners. They would run their races barefoot if they could except…they are sponsored by Asics, Reebok, Nike or whatever-who pay for the races and probably give them a significant stipend. They could probably run faster with no shoes, but the sponsorships get them to the start line in the first place…
Look up the wattage forum on google groups under Tufo tire slam for the relevant articles that point to the assumption that higher psi produces lower resitance. I haven’t seen any other study disproving this point, all the studies so far have done tire testing at 120psi.
…and the most “telling” comment in that whole thread was by Andy Coggan:
tubulars at 175-220psi probably have
lower rolling resistance than clinchers which can’t be inflated above
130-160psi.
Not based on some data that I recently had the opportunity to analyze.
Andy Coggan
Also, Bicycle Quarterly published “roll down” data that a 21mm Clement Criterium rolled slower at 130 psi vs. 105 psi on an asphalt surface.
In addition, our own Jens did a test a LONG time ago with Tufos at 120 and 150 psi. Guess what? They were slower at 150.
There was an article again on that forum that showed that a 19mm tire has a 15watt advantage over 21 or 22mm tire due to aerodynamics at 50km/h.
Really? I’m supposed to believe data from Conti? If they know so much about rolling resistance, why don’t they do something about the fact that all their tires are dog slow? Just a brief glance again at that article (I read it when it first came out) revealed a couple of cases where whoever wrote that article didn’t quite “get it”.
I don’t understand your last point since it proves my point that if they don’t ride clinchers at the pro level there must be a reason for it. Lance spent hours in the wind tunnel testing position, wheel and even clothing. This was a special section on Versus prior to the 05 Tour. I doubt he would waste his time looking for a 1-2 sec advantage in clothing when there was a 30 sec advantage by using clinchers as some here claim by looking at the resistance data.
Hmmm…I guess you never heard of Gianni Bugno winning a Giro de Italia and a pair of World Championships on Michelin clinchers, huh?
I remember that special on OLN. I also remember him talking to the guys designing his skinsuit and they were brainstorming locations for the radio. They asked him something like “Did you ever consider putting the radio in the front?”…and his response was a clear “No” with the facial expression communicating “…and don’t even consider doing it”.
Also, in Coyle’s book he relates the case where after testing out the Trek “narrow bike” TT concept, he and Ferrari discovered that in long TTs his power would tend to suffer near the end. The Trek engineers tried to convince him that even with the lower power output he was still faster because of the aerodynamic gains. It didn’t matter, from that point on, the bike was “junk” in his eyes.
Besides, Al Morrison hadn’t done all his roller testing back in '05 
why wait until the end of the ride?
Shit Eddy lived on Oxford street
.
every one knows they are all riding italian made walmart bikes rebadged to suit the sponsors.
My point is that no one has done the study looking at the optimum outcomes of rolling resistance and aerodynamics at different pressures to show which is the fastest tire. The guys in TDF are switching from their sponsors, covering things up just to ride tubulars. I want to know why ?
Regarding Andy post he hasn’t provided the data, just his comment, and he did not say what he would use in a TT when the question was posed. If he from his recent tests says clinchers are the way to go without providing data I will be more convinced, but would be more impressed for the data and I would be glad to pay for such data if someone does the tests to answer this question. Till then I don’t know what wheel set to buy for a TT.
THey ride all sorts of re-badged stuff in the tour, I know that alot of guys still use re-badged pegorettis instead of the bikes their sponsors give them, thing you have to remember is that most of these guys have been riding since they could walk, so they know what they like and what they dont.
Being a smart assed college student I find that the most simple answer is the correct one. They are riding bikes…that is my final answer.
Those are great pics. I can just imagine the photography sprawled out on the ground to get some of those close-up pics. But that’s why we love the Tour, right?
Of course this is nothing new. Anyone remember Mark Allen riding a “Schwinn” that looked amazingly like a Kestral back in the day? ('90 or '91, I think).
Anyone remember Mark Allen riding a “Schwinn” that looked amazingly like a Kestral back in the day? ('90 or '91, I think).
Allen didn’t hide the fact that he had an affinity for Kestrel as he was one of the first people to own the original Kestrel 4000. Kestrel also had no problem re-badging their frames back then. Many Profile-Design sponsored athletes rode white Kestrel’s that had “PROFILE” on the downtube (Rob Mackle to name just one).
My favorite TDF bikes ever have to be the 7/11 Huffy’s made by Serotta. Awesome.
THey ride all sorts of re-badged stuff in the tour, I know that alot of guys still use re-badged pegorettis instead of the bikes their sponsors give them, thing you have to remember is that most of these guys have been riding since they could walk, so they know what they like and what they dont.
That’s a first… I’ve heard of re-badged Calfees, Walsers, Lightspeeds, Cervelos, Looks… but never heard of a Pegoretti in the tour… who rides them?
Without knowing the particular circumstances of the picture in question, I’d guess that this is a big climbing stage and that the rider wanted the lighter weight of sew ups.
Of course big mountain stages in the tour feature 10-15K’ of climbing, where even small differences of weight are actually significant. The typical triathlete sees the pros using sew ups and thinks therefore he/she should do the same. Never mind that the typical tri course has some tiny fraction of the amount of climbing in a tour mountain stage, making the weight advantage of sew ups a minimal factor. Then they slap the tires on with minimal glue so they can change a flat easily, the tire might be installed with lots of wobble and hop, maybe the tire was poorly made (tubies are made by hand and you know damn well every one doesn’t come out equally good). The end result: they think they’re faster because they’re on sew ups, but really, they’re slower.
Pro tour teams pick and choose their tubies, if one isn’t straight or round it goes back to the manufacturer to be sold to us. Or the tire might not be what the label says it is, it may say continental or hutchinson but really be dugast or veloflex. They glue the hell out of these things (no 10 minute glue jobs) and you can be sure they know how to mount them straight and round. You can also be sure that a big part of the reason that pros usually use tubies is because of ride feel, not performance, these guys are in the saddle 6+ hours a day and small differences in comfort are a big deal for them, and traditionally tubies have had a bit better road feel although this isn’t nearly as true as it used to be.
A carefully selected tubular installed correctly can equal the rolling resistance of the best clinchers. In the real world, tubular performance is tremendously variable, and given the common techniques used by triathletes for gluing, is likely to be on the poor end of the spectrum rather than the best, and significantly worse in rolling resistance than good clinchers.
installed correctly can equal the rolling resistance of the best clinchers. In the real world, tubular performance is tremendously variable,
Technicians??? Good point. It so silly to squeal, “but the pros …” esp. when comparing TDF v. Cat 4-5 riders or (even slower) MOP triathletes … For example the same is true for skis and snowboards on the World Cup:
They are 1.) specially manufactured and 2.)fine tuned way beyond what you can do or what the local LSS (LBS) can do for you.
Think your clinchers really slow you down (or make you faster) by any truly significant amount? A huge array of other factors slow us down way more, people …