Road Bike, Cycling Forums banner
1 - 7 of 7 Posts

· Registered
Joined
·
382 Posts
Discussion Starter · #1 ·
Yesterday I was on a organized ride and about 30 miles into it. My front tire blew, I mean it sounded like a cherry bomb went off. There new tires (gp4000) with only about 300 miles on them. I figure I lost the bead and the tube came out.
Does anybody else have any idea what could of caused this problem ? Bad tube ? Mounted wrong ? I'm a bit concerned because I got a bike ride around Lake Tahoe coming up and some of the descends are 45 mph. Just wondering what I should look out for.
 

· Registered
Joined
·
5,196 Posts
Had one do that once

The hint was new tire. Some tires have a slippery silicone like substance on them almost like tire dressing for cars. I guess it is a preservative for the rubber. That substance when mated with a metal rim does not adhere that well at the bead. Talc powder or similar substance dries the dressing up and it shold not have as much of a chace of coming off. By the way the tire I speak of was a Conti 3000.
 

· Registered
Joined
·
1,860 Posts
Sounds like the tube was pinched between tire and rimt

saccycling said:
Yesterday I was on a organized ride and about 30 miles into it. My front tire blew, I mean it sounded like a cherry bomb went off. There new tires (gp4000) with only about 300 miles on them. I figure I lost the bead and the tube came out.
Does anybody else have any idea what could of caused this problem ? Bad tube ? Mounted wrong ? I'm a bit concerned because I got a bike ride around Lake Tahoe coming up and some of the descends are 45 mph. Just wondering what I should look out for.
Was the tire otherwise fully intact after the blow-out? Like the other posters intimate, the big clue here was "tire recently installed". Normally, a clincher tire is held onto the rim by the clinch between the tire bead and "hook" in the inside of the rim wall. The internal pneumatic pressure from the inner tube pushes the tire bead outward and traps the bead under the "hook", holding the tire firmly onto the rim. If, during tire/tube installation, part of the inner tube gets trapped between the tire and the rim sidewall, the pneumatic pressure in the tube can instead act to push the tire bead away from the rim "hook", eventually resulting in the tire becoming unseated and coming off the rim. Depending on how much of the inner tube gets trapped, this can a mile or several hundred miles.

After installing tire/tube, check to make sure that the tube has not gotten trapped under the bead. With just a few psi of pressure in the tube, push the tube inward away from the sidewall on both sides all the way around the rim, and make sure that that tyou can see the rim bed all the way around the wheel. If you can see the tube poking out under the bead, push it back into the tire.
 
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top