Originally Posted by
Bud Bent
I don't think it's usually the rim diameter, it's just that the valley in the middle of the rim isn't deep enough on some rims. I used some Rox ultra thin rim tape that made things a bit easier, but it only lasted a few months, then started wadding up and moving. I tried Velo Plugs, but the holes in this rim are large enough that I had to use the larger yellow Velo Plugs, and I couldn't get the tires on at all. I'm using some fairly thin stretchy type rim strips now, but it's a serious battle, even with my VAR lever. you know when you have to use a lever to install the first side of a tire, it's going to be a struggle to get it on. And getting it off is even tougher. Back when I had regular rim tape on the wheels, I had to dig it out first to get the tires off at all.
It doesn't take much of a difference, but yes, the valley could be either too shallow or not wide enough, it's almost funny though, you can take the same rims, same rim strip, and with one tire you think there is no possible was it will fit on there, another model or brand of tire, and it goes on smooth as can be. The Kenda tires on the steel rims on the road bike seem to be about 2cm too small, yeah they took levers to get them on there. Noticed part of the rim strip sticking out on the front now, so I need to take that ^%$#!@* tire off again to fix it
. Tomorrow it's supposed to be a nice gentle rain all day so I will sit in the garage and pull it apart and fix it. If the number of tires that fit 27" rims wasn't so small, I would try a different tire, may still. I hope to get different rims over the off season so, the tires may fit those better. Debating though, about getting some low priced 700C rims and putting those on, brake pads have about 5mm of adjustment, so they will fit easily enough. I wonder if by 1975 some bicycle manufacturers realized that the move from 630mm to 622mm rims was inevitable and started lowering brake bridges a few mm to allow for both sizes.