Tubes Bursting on Inner Side

[Eugbug]

I'm plagued at the moment by tubes which keep bursting on the side closest to the rim. There doesn't seem to be anything obvious which is doing this such as spoke heads sticking out through rim tape, grit, thorns or other stuff stuck to the rim. I inflate tubes to the max recommended pressure (65 psi) and this hasn't happened too often before, so the chances are that the tubes are bad quality (even though they are weighty and not cheap).

I've found that patching holes on the inner side of a tube doesn't work too often because the tube has to stretch and deform as it pushes into the rim, loosening and blowing off the patch if inflation isn't quick enough.

Any tips for repairing these these types of holes?

[cny-man]

First we need to understand what you mean by "bursting." Usually one would read that as an explosive release, accompanied by a loud noise and a sizable hole - typically either star-shaped or a long slit. If that describes your problem then it has absolutely nothing to do with tube quality or anything in the tire or rim. A tube cannot have an explosive flat without first escaping the confines of the tire. Such an event is caused by either improper mounting (operator error) or some sort of defect with the tire, such as a hole or a weak/broken bead.

If that is not the case and it's merely a leak, then we need to know exactly what the hole does look like, and whether the problem occurs in the same relative place on the rim or tube. I have never seen a particular problem with a properly done patch holding on the inner side of a tube.

[Eugbug]

(11-16-2014, 09:36 PM)cny-man Wrote:  First we need to understand what you mean by "bursting." Usually one would read that as an explosive release, accompanied by a loud noise and a sizable hole - typically either star-shaped or a long slit. If that describes your problem then it has absolutely nothing to do with tube quality or anything in the tire or rim. A tube cannot have an explosive flat without first escaping the confines of the tire. Such an event is caused by either improper mounting (operator error) or some sort of defect with the tire, such as a hole or a weak/broken bead.

If that is not the case and it's merely a leak, then we need to know exactly what the hole does look like, and whether the problem occurs in the same relative place on the rim or tube.

The holes are pin holes which develop spontaneously and cause deflation over a period of about a minute. On one tube, they developed at two different spots.

Quote:I have never seen a particular problem with a properly done patch holding on the inner side of a tube.

I've repaired hundreds of punctures where the hole was caused by thorns penetrating the outer surface of the tube. None of these patches failed. Patching the inside seems more tricky.

[cny-man]

OK, that takes care of the "bursting" problem, and thank you for describing them as pinholes. It is extremely rare for any tube to just develop a hole - there is generally a cause, especially when there are multiple occurrences on the same wheel. It's necessary to keep track of exactly where the problem develops relative to both rim and tire position and then carefully investigate in that area each time. Rim tape can shift, which on a double-walled rim can expose a sharp edge of the nipple well to the tube, for example.