Originally Posted by
mschwett
definitely too tall in localized spots, a couple inches across. too tall by perhaps 3-4mm.
when uninflated, the bead of the tire would sit in the deep trough in the middle of the rim, next to the tube. it can’t be pulled “out” under the hook since there’s nothing to pull it by, or keep it out there - naturally it wants to return to the middle. orange profile doodle below.
for 80% of the circumference, inflating the tube pushed the bead into the correct position, from the orange at-rest position to the correct grey spot under the hook. for a little bit, different spots each time, inflating the tube partially pushed it into the red position.
hitting it to 100psi from a compressor instantly popped it into the correct position…. but it’s not like i could do that roadside with a hand pump. at least i don’t think i could.
When I was in college riding a "10 speed" (mid-70s), my friend who was much larger and fitter than me could get 100lbs with his full-length frame pump. I don't know if he could still. But I was just thinking, what would a large CO2 inflator do? It pops up a tubed flat pretty quickly.