onewheeldave wrote:
*... just before getting to 65 there was a really loud bang as the
tube exploded!
*

Was the tube sticking out from between the rim an the tire? If so, I
did the same thing when I put a Big Apple on a 700c rim.

It's caused by two things - an improperly seated tire and too much
pressure. The bead of the tire has a wire in it to keep it from
stretching. If the bead is evenly seated under the hook of the rim all
the way around then the tire pressure pushes it evenly into the rim and
it's cool. If it's not hooked well at one spot then the tire pulls out
at that point and releases the rim to open air. Blamo!

The cure is to a) not overpressure the tire (usually 20-30 psi higher
than the number on the casing, which is why I got fooled. The Big Apple
went at 60 psi.), and b) seat the tire well. This is quite simple to do
- put 3-5 psi into the tire, just enough to firm it up, then slowly spin
the wheel and look at the bead. Is it even all the way around? If not,
then push/mush the bead around until it is. Then raise the pressure to
where you want it. If the bead isn't set right the tire will blow well
below it's max pressure.

onewheeldave wrote:
*Would it be true to say that, given pressure is not so low that pinch
flats are a problem, that going much higher makes normal punctures
more likely?

Also, as the tyre ratings are meant for a bike, couldn't it be the
case that they would not apply when used on a unicycle, as, being one
wheeled, there will be around twice the stress on it?
*

You're about right at 50 psi. Just get the bead to seat right. If it
just won't seat right then it's a bad combination of tire and rim.

onewheeldave wrote:
*Can anyone briefly explain what causes a pinch flat;
*

The sidewall of the tire bulges out when the tire is compressed, part of
the tube goes with it, and the rim pushes the part of the tire just
above the bead through both layers of tube. Hence the nickname
"snake-bite" flat. There are usually two holes or slots.


--
cyberbellum - Level 1.0 rider!

I was standing in the park wondering why frisbees get bigger as they get
closer. Then it hit me.
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