Rogers' crash?

[LegendRider]

There is some speculation that he rolled a tubular. Any confirmation of this? Or, did he just overcook a turn?

[zeroking17]

Reminded me of Beloki's horrific crash a few years ago in the TdF. Here's what I speculate are the common elements:

1. Carbon rims
2. Descending
3. Friction of braking causes glue in rims to heat up, which in turn makes the braking even more "grabby."
4. Eventually braking modulation becomes nearly impossible.
5. Rear wheel locks up under braking, causing wheel to slide sideways.
6. Tire pulls away from rim.
7. Big crash.

[David Kirk]

It looked to both Karin and I that the tires were still in place after the crash......so either a rolled tire was hard to see of he just overcooked it.


Dave

[zeroking17]

It looked to both Karin and I that the tires were still in place after the crash......so either a rolled tire was hard to see of he just overcooked it.


Dave

This photo shows that Rogers' rear tire has pulled away from the rim. Of course, the photo can not show whether the rolled tire caused the crash, or was an effect of the crash.

[jberk]

I could have sworn that the video showed that the tire had come off the rim. It is not clear whether that was the cause of the crash or the result of his having hit the guardrail.

[LegendRider]

Carbon rims dissipate heat better than aluminum, right? Do they still heat up enough to melt glue?

[Kevan]

Posted by Michael Rogers on 16 Jul 2007 at 18:51

Tags: Tour de France, crash, Michael Rogers, T-Mobile Team

Yesterday my Tour came crashing down around me, literally! I was going pretty well in the first really big mountain stage of this year’s race when, 53km from the finish at Tignes, I came off in style. Needless to say it is a massive disappointment. I could see the yellow, I could taste it – now it’s gone. It's bad luck, but I'll be back.

I’m now writing to you from Italy where I am having treatment for a dislocated shoulder.

Such a big and fast descent as the Cormet de Roselend can indeed be hazardous, but injuries can be made on such fine lines. I was following David Arroyo of the Caisse d'Epargne team when I lost control and ended up in a ditch. I hit the tarmac hard while Arroyo was lucky to get a 'softer landing' and could carry on. To be honest I don't really know what happened, I was going through the corner and then found myself on the ground. On the descent I came back to the leaders but once we started climbing again I just couldn't hang onto the handlebars anymore.

Considering I was in "virtual yellow jersey" position when I came off it is even more annoying. I knew straight away that I had done some serious damage as I was in quite a lot of pain but your first instinct as a rider, particularly on the Tour de France, is to try to carry on, get to the end of the stage and hope that some physio and a night’s rest will help. It was clear to me quite quickly, however, that I wasn’t going to make it to Tignes – it is probably the hardest decision to make as a professional rider but once I was overtaken by the peleton with 28km to go, I knew my time was up.

It was a bad Monday overall for my T-Mobile Team, with both Patrik Sinkewitz (after a fall which broke his nose) and Mark Cavendish (who it was always planned would withdraw once we reached the Alps) ending their races. T-Mobile is now down to just six riders. It will be a huge test for those remaining but we have some great talent and it will be a learning experience for them all. As for me, I’m going to focus on recovery and get back on the bike as soon as I can.

Posted by Michael Rogers on 16 Jul 2007 at 18:51

[Elefantino]

Obviously Mick didn't read this thread because he didn't answer the question.

I don't get the carbon-rim-overheating thing either. Maybe a physicist can 'splain it to us.

[zeroking17]

Posted by Michael Rogers on 16 Jul 2007 at 18:51

Tags: Tour de France, crash, Michael Rogers, T-Mobile Team
<snip>

Yesterday my Tour came crashing down around me, literally! I was going pretty well in the first really big mountain stage of this year’s race when, 53km from the finish at Tignes, I came off in style. Needless to say it is a massive disappointment. I could see the yellow, I could taste it – now it’s gone. It's bad luck, but I'll be back.

<snip>

Posted by Michael Rogers on 16 Jul 2007 at 18:51

Well, I don't think any of us will ever hear an injured rider blame his equipment sponsors...

I'm piecing together my speculation based on various comments I've read on German cycling forums. In particular, one person reported that immediately after the crash a T-Mobile mechanic jumped out of the car to help Rogers. Rogers apparently pointed at the rear wheel, as if to indicate "that's what caused this."

But hey, it's all speculation. It's a real shame that Rogers had to abandon the Tour. It would be an even greater shame were it caused by equipment failure.

[72gmc]

I think the simple answer is the right guess in this case. Arroyo overcooked the turn first, and Rogers was following too close/trusting too much. Arroyo wound up hitting the barrier head-on and auditioning as an arborist, while Rogers tried to save it and wound up taking the brunt of the barrier in his right shoulder. The tire pulled off as a result of the crash. He pointed to it because his mind was immediately on rejoining the race, and the tire needed attention.

Of course it would be more exciting if something else happened...

[zeroking17]

Carbon rims dissipate heat better than aluminum, right? Do they still heat up enough to melt glue?

I thought the opposite was true, that aluminum (as a better conductor) dissipates heat much more efficiently than does carbon (which is a poor conductor).

Buy hey, I don't have a master's in science (1), so I'm willing to be shown the error of my ways.

----------------------------------------------
(1) Oblique reference to "Ask Dr. Science," who used to be my neighbor.

http://www.drscience.com/

[zeroking17]

I think the simple answer is the right guess in this case. Arroyo overcooked the turn first, and Rogers was following too close/trusting too much. Arroyo wound up hitting the barrier head-on and auditioning as an arborist, while Rogers tried to save it and wound up taking the brunt of the barrier in his right shoulder. The tire pulled off as a result of the crash. He pointed to it because his mind was immediately on rejoining the race, and the tire needed attention.

Of course it would be more exciting if something else happened...

You could be right, but in this scenario I'm having a hard time imagining how the rear tire (but not the front tire) would be pulled off the rim.

[LegendRider]

I thought the opposite was true, that aluminum (as a better conductor) dissipates heat much more efficiently than does carbon (which is a poor conductor).

Buy hey, I don't have a master's in science (1), so I'm willing to be shown the error of my ways.

----------------------------------------------
(1) Oblique reference to "Ask Dr. Science," who used to be my neighbor.

http://www.drscience.com/

I seems that you're correct. I found the following:

Good braking has been one of the most difficult technical challenges for full carbon wheels. On one hand, the smooth hard and slippery epoxy surface of an untreated rim braking wall does not provide enough friction for high performance braking. This is aggravated by wet conditions, which make braking dangerous. On the other hand, carbon-epoxy materials cannot diffuse heat very well. The increase in temperature affects not only the dimensional stability of the rim, but also the adhesive bond of the tire on tubular rims. Again, the consequences are dangerous and undesirable. Most carbon rim manufacturers have implemented solutions that treat the braking surface with extra layers of materials such as ceramics.

[ThasFACE]

I think the simple answer is the right guess in this case.

http://en.wikipedia.org/wiki/Occam's_Razor

[ada@prorider.or]

Good braking has been one of the most difficult technical challenges for full carbon wheels. On one hand, the smooth hard and slippery epoxy surface of an untreated rim braking wall does not provide enough friction for high performance braking. This is aggravated by wet conditions, which make braking dangerous. On the other hand, carbon-epoxy materials cannot diffuse heat very well. The increase in temperature affects not only the dimensional stability of the rim, but also the adhesive bond of the tire on tubular rims. Again, the consequences are dangerous and undesirable. Most carbon rim manufacturers have implemented solutions that treat the braking surface with extra layers of materials such as ceramics.



well the problem on carbon wheels was solved in 1997
with a kevlar braking surface as i did
and never see again such braking problems


so it can be done ,as we has shown

cees

[regularguy412]

You could be right, but in this scenario I'm having a hard time imagining how the rear tire (but not the front tire) would be pulled off the rim.

I experienced this problem MANY years ago on an old department store bike with a banana seat. Was going down a hill WAYYY too fast and the traffic signal at the bottom turned red my direction. I slammed on my coaster brake which effectively locked up the back wheel. It started to skid sideways. When I slightly let up on the brake to stop the slide, the back wheel hooked up HARD. The abrupt adhesion by the rear tire sent me over the high side and out into the middle of the intersection. Other than my scrapes and bruises ( including a bruised ego ), the back wheel of the bike fared far worse. Admittedly it was an old clincher 'chrome' rim with zinc spokes. However, the jolt of the back wheel getting grip all at once was enough to warp the rim, bend spokes and flatten the rear tire. At best, I was only traveling 40 kp/h. If Rogers experienced a similar scenario, I would imagine that even the best-guled tire could roll off in an 80 kp/h descent.

Mike in AR

[pdxmech13]

I'll agree with what was said as he over cooked the turn trusting Arroyo a litlle more than he should. Equipment isn't at fault here as all pro's know how these products ride these days. plan and simple he shiite the bed again. Mick is one of those riders that will never live up to his potential until he finds the rite mentor.

[frenk]

he sure knows better than me because he was there... but from what I've seen in TV Arroyo was closely following Rogers, not the other way round.

[Climb01742]

cees, how about the build-up of heat? is that an issue with carbon rims on a long mountain descent? is there a way to dissipate the heat?

[ada@prorider.or]

cees, how about the build-up of heat? is that an issue with carbon rims on a long mountain descent? is there a way to dissipate the heat?

with carbon it is yes
this cause the resin to melt end if you take a resin that can resist this heat there is a problem with braking also due to the extreme hardness of the braking surface (think about formule 1 disc brakes that had to be heated first to work)

and you can solve this problem by isolate the heat
this is done like with kevlar that can easy handle this with out any problem


hence its used in brake´s at cars also and in friction plates

but the make a good kevlar braking surface is a pain in the *** to do ,but as we done can be done

[RPS]

and you can solve this problem by isolate the heat
this is done like with kevlar that can easy handle this with out any problem
Are you saying the braking energy is converted to heat at the kevlar braking surface and that the kevlar also prevents the heat from transfering to the rest of the rim, thereby keeping the rest of the rim cool or cooler?

[Louis]

More tire issues, this time for Millar during final ITT. From the TDF web site:

14:27 - Millar retardé par un problème mécanique

Le mauvais départ de David Millar s’explique par un problème juste après le départ de Cognac. Sur la roue arrière de son vélo, le pneu s’est détaché de la jante. Le coureur Ecossais a dû changer de vélo avant de repartir...

Basically says that Millar's mechanical problem was caused by the rear tire (pneu) detaching itself from the rim (jante). No heat-related problems here - I would think it was due to a bad glue job...

[Grant McLean]

More tire issues, this time for Millar during final ITT.....

Basically says that Millar's mechanical problem was caused by the rear tire (pneu) detaching itself from the rim (jante). No heat-related problems here - I would think it was due to a bad glue job...


Don't think it's the tire. It looked like the whole aluminum braking surface
seperated from the carbon disc. Never seen that before! The tire looked
stuck to what was left of rim. Phil kept saying his chain was broken,
i don't know if that jamming between the frame the wheel could cause a
failure, but something wacky happend. I need to look at my tape again.

from cyclingnews.com live coverage:
13:44 CEST
Wow...that's terrible...David Millar had just started his TT and his Mavic TT wheel disintegrated. The rim came clean away from the carbon covering. He threw his bike down in disgust and got another one. That'll cost him time though. Millar was aiming to try to win today's TT.

interview:
"The Mavic disc exploded in the first five hundred metres," Millar explained at the finish. "The rim just ripped off the carbon, twice. I did not give up and I headed for the first time check, saying 'if I was a minute or under then I would keep going.'" Instead, he was close to two minutes behind then leader Vladimir Karpets (Caisse d'Epargne).

"The first one literally exploded. I went another 300 metres and that one went as well. The car was right there, he had to take the wheel off of Iban's [Iban Mayo - ed.] bike and put into this one because he did not have time to change the first one.

g