Originally Posted by big john

That little curved part in the middle? That part we used to call the spoke bed? Some of these rims don't have that, they're flat across. The question I was asking is during a tube installation on the road where it wouldn't be necessary to break both beads why is it harder to get the tire back on if there's a tube in it? How does the tube interfere with stretching the tire bead? If it's just the tube makes things more crowded and takes room from manipulating the stupid tire, I guess I can accept that.

Originally Posted by MinnMan

Yes, that's the idea. Ideally, if the tube is up in the tire, far away from the bead, then it causes fewer problems. You don't want it interfering with placing the "other" bead close to the center channel, and of course you don't want it near the part of the bead that you are working to slide over the rim. But it's hard to get it to stay out of the way, particularly near the valve, and this makes it harder to pull the bead into the rim channel to produce enough slack..