Just wanted to see if this is a wide-spread problem.


I ordered six Michelin Aircomp inner tubes from PBK in late march. Thus far, I have used three of them, and all of three have developed slow leakage problems. The first one did so two weeks ago and cause a pinch flat after my tyre ran over a small pebble. The second one developed this problem this past Wednesday after one week of use, and the third one was mounted on Wednesday and developed a slow leak on my ride today. I used to think these were very trustworthy tubes, but it seems like i really got a bad batch. Does anyone else have this problem?

Turn your tires inside out and look for tiny wires or glass.

I was on a group ride last year where the rider's tube had a really slow leak. The replacement tube had the same problem. We all looked at the tire carefully and didn't see anything. When the rider got home, he finally found a tiny wire embedded in the tire.

A cotton ball wiped around the inside of the tire is supposed to be good for finding these small objects -- the fibers will snag on it.

It sounds like you've used these Aircomps before. But someone new to using them might not know they leak a significant amount of air overnight, since they are thin.

thanks for the suggestion, i'll take a look. when i flipped over the tire to check for cuts, i saw nothing

The advice on checking for tiny embedded wires is a good one. I had a slow leak during a ride that ate up two spare tubes and a lot of my patience. Eventually, I pumped up the tubes and back traced the tiny holes in the tubes to an embedded wire that's not much thicker than human hair and about a quarter of an inch long. That bugger was not detectable using the run-fingers-through-inner-side-of-tire trick that we all use during tube replacement. Apparently, as far as I could tell, the wire only stuck out when the tire was flexed, as when that part of the tire rotated through the contact patch. I only found it because the punctured tubes all had their tiny holes in the same location. It also helped that I was sitting at a coffee shop taking my sweet time addressing these confounding punctures so I could get home without having to air up every 5 minutes.

oh man, i'm glad i'm not the only one. I have this same problem too. I fill it up and 1-2 days later, it's lost a significant amount of air pressure. I thought this was normal so I didn't think much of it, but now that I know, I guess I'll have to buy new tubes now