Ideas for consistently popping tubes

Question

I ride a cyclocross about 50 miles a week. About half of the mileage is spent on roads, the other half on single track trails. In the space of 3 weeks I have had the tubes pop 5 times. Once the back tube popped while riding on the road near my house. The other four occurred while the bike was hanging in my apartment.

I have double checked the interior and exterior of the tires for debris or objects and found none. I ensured tires were inflated to proper pressure and that the rim guard strips were in the correct place. I purchased the bike about a month ago from the neighborhood bike shop.

Is there anything I am missing? My current hypothesis is that the tubes degraded in the shop and spring leaks due to age. If that is the case, is it proper to ask the shop to replace the tubes with new ones?

Edit: August 2016

Hundreds of miles later on the same tires, rims, rim tape I have not had a single flat. I replaced the problematic tubes and tried to hold all other variables consistent. I was not able to determine the cause of the problems but it does appear the tubes that came installed from the bike shop were more brittle than expected. This could have been due to shop storage. Extended exposure to heat or light can weaken butyl tubes despite being more resilient to weathering and attack than natural rubber.

Answer 1

I had tire busts when I used tubes that were pre-filled with Slime: they burst within an hour to a day of installing them. When I switched to standard tubes and then added Stans No Flats liquid they were fine. This happened twice to me: very strange.

I always use Stans in my wheels: either MTB tubeless or commuting/road bike tubed. Is a bit of a hassle with Schraeder tubes because the tubes with removable valve cores are not so common (altho Continental sells). But I use a syringe and a tube to "inject" 50ml of Stans into the tubes: helps a lot with flats (although won't solve this issue).

Are you using really light tubes? I've found them more likely to cause problems if your rim/tire combination isn't exactly right. Also check that your tubes really are the right size for your tires: not just the diameter but the width. It might be worth spending a bit more and getting better quality tubes next time: I've found Continental good, and they offer a big range of tubes. Maybe you're using big fat cyclocross tires and tubes mean't for a road tire. They all fit, but will be much more stretched, and more likely to fail, especially if the rubber is not good quality and tough.

When you install the tubes, are you maybe pinching them? I partially inflate them and try to install just using my thumbs. Then I go around the wheel and roll the tire back and forth with my fingers and make sure the tube is not trapped under the bead: check both sides. Then I pump it up to max and possibly deflate it a bit if I don't ride it at max pressure.

I doubt it's your tires, but try taking them off and running your fingers around the inside: you can feel problems better than see them.

I also doubt it's your rim tape, but I often add a layer or two of electrical tape over it: especially if I am using high pressures.

If nothing is wrong in particular, I bet you can solve it by using better quality tubes.

Answer 2

Based on the description you gave in one of your comments, your problems strongly resemble pinch flats, i.e. "snake-bite" flats. Although Sheldon Brown recommends in the linked article mainly to ensure that the tire pressure is correct, I've found that a common reason for this is old or improperly-placed rim tape: If the rim tape isn't doing its job, your tires will be fine for short, gentle rides but you'll get problems once you start to do some longer/harder riding.

In order to check if you've got rim tape problems, when you get a flat,

1. very carefully take the tire off of the rim without moving the inner tube: You want to be able to inspect the inner tube in relation to the rim itself.
2. Very carefully remove the inner tube up and away from the rim, once again without moving the tube in relation to the rim.
3. Check the underside of the inner tube for punctures-- if you find one, find the corresponding spot on the rim, where that part of the inner tube contacted the rim while riding.
4. If the puncture lies directly on top of a spoke hole, your rim tape isn't doing its job; Get some new tape. If your rim has recessed spoke holes, you'll have to be extra careful to get rim tape which is designed specifically for the pressure you intend to pump your tire up to, e.g. Schwalbe High Pressure tape.

Answer 3

Not sure what you mean by "popping", are you talking about literally exploding or just getting a cut/pinch/slow leak/etc? Knowing what the hole looks like could help point to some cause.

If you've had 4 flats while hanging I would guess something is cutting into the tube. I'd try a different tire or pick up a tube from somewhere else and try it out.

Answer 4

If you have holes coming up all over the place on two tubes and then bad tubes is a likely cause. Stop patching the tube and put in some new tubes. If the new tubes pop then look for the cause. Always match up the hole to the tire / rim and see if you can find a cause.

You could have a case of bad tubes installed by the manufacturer.

Best use of a patch is to just get you home. A patch is not as strong as a tube and will not last as long. The glue will dry out. For $6 it is worth a new tube as failed patch is a flat tire.

I have a beater bike that I only use in the neighborhood. I use only patch tubes on that bike. I save up tubes and just patch 4 at a time. I will use a patched tube if I don't have a new. Another trick is if the hole is too big to patch then save the valve core and cap.