Originally Posted by
JohnDThompson
The tube will expand to fill the space available. But it will also be stretched thinner than a properly sized tube, and thus arguably more prone to puncture.
That's a fair point (not to mention, obvious, since it was already stipulated in the OP
). But we've all seen how easily a tube will stretch (cross sectionally) as big around as a soft-ball, plus, I'm not talking about using a 700x23 tube in a 2.2" mtn tire.
Mathematically, yeah, the tube has to get thinner as it expands, but if we draw a circle that's 32mm around, then draw a circle that's 40mm around, and compare the two, I'm having a tough time imagining there's a gonna be real-world difference here in the tube wall thickness, and it's puncture resistance.