jeffmendoza

Hi All,

First of all, I'm new to road cycling. I still have my mountain bike from when I was younger, and started riding that around the neighborhood lately.

I just bought a vintage motobecane from the thrift store. It was in pretty good shape, so I just bought tires, tubes, and rimtape(rubber-band style). The bike has 27" rims, so I got 27 x 1 1/8 (ISO 28-630) tires, same as the rotted ones that were on there. The tires are rated at 100psi, so that is what I filled them up to.

On the way home, my back tube blew out. I immediately stopped and took a look at my back tire, one bead was off the rim and the tube was kind of hanging out. I had just ridden by some sharp looking small rocks, but I thought I missed them.

Upon inspecting the tube, I found a large 4-5" cut along the seam of the tube that rests against the rim. And I don't see any large holes in the tire. This has me puzzled.

Maybe I did run over a sharp rock that caused a blowout which caused the tire to come off the rim, then the tube tore on the seam while stopping?? And I haven't looked close enough to see the hole in the tire?

Another possibility: Since I don't have any road cycling experience, just mountain bike, I have no idea what amount of abuse is tolerable for these kinds of tires. I did ride to work and back on the sidewalk, which has bumpy joints. Also, there were some bumps on the pedestrian ramps (the type for the blind). I didn't go over any curbs or anything though. I only weigh about 140 pounds, and only had maybe a 10 pound bag with me. I didn't see any 'snake bite' holes in the tube though (again, maybe I haven't looked close enough). Is is possible for the tube to just split at the seam from abuse? I thought it was the tire that held the pressure? Can you give any guidance on what I should and shouldn't do on these tires?

I just don't want to buy another tube and have the same thing happen again tomorrow, Thanks.

bikinpolitico

Road tires should take the abuse you mentions without problem. Sounds like your rim tape may have gotten moved out of the way when you installed the tire and tube. If the tear was on the rim side of the tube, then that's the likely culprit. The rubber band kind you mentioned are prone to this. I'd get rid of them as then generally suck. Get yourself some Velox cloth rim tape and you'll never worry again.

cliffbatson

I would be puzzled too. I've never had a tire come off the rim with a flat. Maybe it's because my rims are kind of high (Matrix Vapor) which also makes it hard to remove the tire when I have a flat.

I had my first flat yesterday in the 3 weeks that I've been commuting. I took a different route home than my usual. As I passed near a construction site, my back tire went flat. Crap! It's hot here in the South in August! I found some shade, installed a spare tube, pumped it up with enough air to get me home, and made it home okay... but I hope that doesn't happen again... what a PITA.

On my hybrid, I recently put Specialized Armadillos (puncture resistant tires) but I was on my other bike yesterday (touring bike with panniers).

When/if this becomes a problem, I may switch to puncture resistant tire on my touring bike. For now, I'm fine with avoiding that construction area and hoping for the best!

By the way, please consider not riding on the sidewalk. Believe it or not, you're safer on the side of the lane in the street. Wear a mesh flourescent reflective vest, etc. and be content with looking like a dork... a highly-visible safe dork.

truman

I agree that it's probably a rim strip.


I got a flat on my long-ago first commute, too. I failed to check the tire for the culprit, so I got another one as soon as the 1st was fixed. Luckily I was .25 miles from my wife's workplace, so I pushed it there and stole her car to get me home.

JR97

Maybe try 89-90 psi to be on the safe side. could have been a faulty tube batch or something.

jeffmendoza

I did check the rim tape, and it was still in place, but I'll look closer.

It is odd to have the tire come off the rim when you get a flat?

When I mounted my front tire, I didn't center it properly (again, first time on road tire), and the tire came off the rim and the tube busted. The next time I made sure to check that it was properly mounted every few pumps.

Could it be possible that my tire isn't properly sized? and that it worked its way off which caused the blow out on the tube? My rims are the straight wall type, not hooked or anything. The problem with this theory is that the long slice near the seam looks nothing like the hole In the front tube from when it blew when I was first mounting the tire.

I was able to mount the tire using my hand only, no tools.

jeffmendoza

Yes, I've been reading about this on the forum and will take it into consideration. Where I ride there are very few places of business for people to turn into, and I stopped to walk in the crosswalk for the one intersection. I'm scared about riding on the street pretty slow, when the cars behind me will be doing 50-60 mph over a crest.

bikinpolitico

It's possible that the tire was the wrong size. 27" is not the same as 700c so I'd make sure you truly have a 27" tire. It's equally possible, they just slide on and off easy. My experience is that how easy a tire goes on is very dependent on the specific tire and rim you are using. As long as the hooks seat tightly on the rim lip, there shouldn't be a problem.

I still think this sounds like a rim strip problem. As I said the rubber one are rubbish. Get cloth.

rumrunn6

Maybe the tire came off and you got that huge gash because you didn't realize the tire was losing air and you were rolling fast enough, far enough, and maybe weight enough to go flat and ride on the rim for a few feet. Riding on a completely flattened tube/tire can cause lot's of problems, including wrecking the actual wheel itself.

I always check my tires before I ride and while I ride. I keep an eye on them to be sure they are always up to pressure. Keep your ears open to so that you can here the hiss from a puncture before you go flat.

Quickbeam

I bet the tire bead wasn't seated quite right in the rim and while you were riding, it blew off.

CliftonGK1

This is my guess, too.

Whenever I put on a new tire or replace a tube, I always pump the tube up to about 25psi and rock the tire in it's "squishy" state back and forth, moving around the entire wheel, to check and see that the whole thing is seated properly; bead settled into the rim seat, and the tube isn't twisted or caught on the bead anywhere.

JeffS