Originally Posted by
Bluish Green
I agree with Chef that you should consider this possibility - if you have the crappy thin rubber rim tape that came with the bike, replace it with cloth tape ($2 at your LBS). The only two flats I have had (front and back, same day) were due to my 100 psi tubes finally pushing through the thin rubber rim tape that came with the bike and puncturing themselves on the sharp spoke ends.
for double walled rims
Generally, it is not spoke ends that cause the puncture, nor does the edge of the spoke hole cut the tube.
The 'puncture' results from the inner tube stretching too thin/too far in a highly localized area. Inner tubes act as a seal to keep air in, but do not actually resist pressure on their own; the tire and rim are what contains the air into a pressurized space. With a double walled rim, the holes on the inner wall do not support the tube thus it expands into the opening till it pops. Same concept as when you get a sidewall tear and the tube bubbles out like a pimple...
cloth tape is needed on double wall rims to bridge the spoke holes and keep the tube contained.
rubber strips are stretchy and will eventually get pushed through
single walled rims are a different story; spoke ends really do intrude into the inner tube's living space. rubber strips are good here since they are thicker than cloth and will smooth over the produding spoke nipples better...
Often the people who spec bikes for mass market are not actual mechanics or cyclists and dont realize the distinction other than the rubber rim strip is cheaper than the cloth one. So new bikes often have the wrong thing.... works ok on the display rack; not so once fully pressured and actually ridden a month or so...