Saturday, November 17, 2007

Tubulars Exploding and Peeling Off

In high speed crashes, the intense heat generated due to braking and friction can heat up the rims of the wheels. If one has tubular tires on, the glue can soften and the tire as a whole can peel off leaving the rims exposed to more damage. I think this can be made even more worse when its a hot day and the asphalt is scorching.

Two videos I looked up to show you this. The second one pointed by Ryan Cousineau from RBT, thanks Ryan!

Video Clip 1

On stage 8 of the this year's tour de france, Australian Michael Roger's from the T-mobile squad had a spectacular crash along with David Arroyo who went over the safety rails and plunged into some trees. Sad for Rogers, who simply lost the tour right then and there... a more spectacular event from a mechanical standpoint was Roger's rear tire peeling off due to the crash... or maybe its whatcaused it.. considering that he's a good descender. Look at 0:40-43 secs. Again, except for Roger and his mechanics and a few others,we are not really sure how this happened. Perhaps it was the tire deflating prior to the crash and the braking that made it peel off? This can happen and I've seen it in clincher tires.

Video Clip 2

During the descent into GAP in stage 9 of the 2003 Tour, Beloki takes a horrendous spill. It was a scorching day and the tarmac was literally melting, the corners were dangerously slippery. Beloki slipped, braked hard, locked up his rear wheel and then the bike's control slipped away from him. The heat was so much, it made his tubulars peel away and explode, and at that point he was on his rims. Lance's escape route is stuff of legend.

One more reason to show you how tough and risky the sport of cycling is, probably the toughest of all.

Solutions ?

1. Go with a slightly wider tire for steep descents? I've read Jobst Brandt saying this will prevent a small volume tire from heating up so quickly.

2. Inflate the tires maybe 10 psi less than max?

3. Take a more deeper section metallic wheel to your high speed descents (?) since more surface area quickens the heat dissipation to the atmosphere.

4. There's no substitute to keeping one's head up, and anticipating a misfortune down the road. This way, one need not apply sudden, continuous braking. He or she can pump the brakes to stop well before the danger spot.

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1 comment:

Nathan said...

the obvious solution is some sweet carbon brake rotors like they have for F1 cars. That wouldn't create any rim heat at all, and you could probably use lighter rims with better aero shapes.