Over the weekend, I put on new rubber and chaned out a couple of broken spokes on the rear wheel of my bike.
Since then, I’ve patched the brand new tube twice, and I’m going for a 3rd tonight. Somehow, it is being skewered on the inside (rim side, not tire).
Last night, when I fixed it, I spent a lot of time running my finger around the rim, and I couldn’t feel any burrs, artifacts, or spoke ends that would make the puncture. The spoke barrier is intact.
The only commonalities are the puncture is in the same general location on the tube, which happens to be where the seam for the ends of the rim are located. I can feel the seam when I pass my finger over it, but it’s not sharp or rough enough to do the job.
FWIW, I’m a big guy, so I’m hard on the bike by definition; the tires are Bontragers (good qualty); I have a liner between the tires and tubes; and everything appears to be normal otherwise. I fix the puncture, put it all back together, fill it up (80 PSI), and the tube will be flat within the hour, without riding.
Any ideas? I’m tempted to get another set of barriers to go between the rim and tube…
What about a burr on the tire bead? Maybe it’s coincidental that it’s getting punctured in the same place on the rim. It may also be the same place on the tire bead.
At the moment, I don’t think so. When deflated completely, the tires are so loose that I don’t need tools to take them off the rim, and I’m so klutzy that the tire comes off anyway when I’m trying to fix the tube. It would be one hell of a coincidence that I put it back on to less than 1" difference from the previous mounting.
If the hole tonight is in a radically different position, then I’ll look at the tire more closely.
The traditional fix for this problem is to line the rim at that point with duct tape. It’s not thick enough to cause a noticable thump, and wheel balance doesn’t matter on bicycles. There’s usually a big rubber band that’s supposed to cover the spoke ends, but sometimes it goes astray.
I once suffered several flats due to the “big rubber band” squeezing off to the side, and then the spoke ends popped holes in the tire. I got thicker rim liners with adhesive on one side that worked great at preventing this. If that’s the OP’s problem, I’d suggest trying it.
It seems you have all the points (no pun intended) covered, yet I have one thought: how are you inflating the tire? IIRC bike tires need to be inflated slowly to prevent the tube from being unevenly stressed within the tire body-part of the reason tubes are powdered, so they have some ‘slip’. As such, I use a manual pump even though there’s a perfectly capable industrial grade air compressor sitting a few feet away.
The way to do this is to take the tube out, and make sure you know which way it was oriented in the rim.
Pump in a little air and find the puncture, then try to line up the tube against the rim to give you an inidcation where the location of the puncture causing object is.
The giveaway will be if you have the two punctures in the same place, this would point to perhaps beading from the tyre coming away or perhaps too long a spoke - I noticed you mention chaing out a couple of spokes, this must be an Americanism, does it mean you replaced those spokes ?
Do you partially inflate the tube so that it stays inside the tire when you’re getting the tire back on the rim? That keeps the tube from getting under the bead and getting punctured.
I sat down this weekend, and tried patching the tube a 3rd time. This time, the leak was in a completely different spot, and was in a score pattern that looked like the cords in the sidewall abraded the tube. The pattern repeated several times at regular intervals.
Still didn’t hold, so I trashed the tube and used my spare. I also went as slowly as my industrial sized air compressor would allow. No problems so far.
Also, let me relate a moment of extreme enlightenment (or a big Doh!) I had while riding yesterday.
We had a 5 hour blackout yesterday because of a power line failure of some kind. I was feeling bored, so I thought I’d take a fast shakedown ride on the new tube. Under the best circumstances, the smell of burning rubber means something is wrong, but doubly so on a bicycle. A quick look revealed that when I reconnected the brakes after putting the wheel back, I didn’t get the little nipple thingy back into the bracket properly, and my shoes were rubbing the rims.