Originally Posted by
trailangel
For all you that ride these wide rims with narrow tires... 23mm tire on a 25mm ext. width rim. Even if the tire does not come off the rim when going flat, have you thought about that you may be right down on the rim with no rubber to protect the rim? Riding at speed, get a flat tire and you are down on the rim before being able to stop the bike.
My 23mm GP4000S on a HED Ardennes+ 25mm OD rim were fine when I got a flat. The beads are locked in the rim (tubeless style bead hooks) and the tire squashed flat, so the rim was off the ground. Tires on narrower non-tubeless rims would usually let a section of bead drop into the center well of the rim, so that part of the rim was scuffed on the ground anyway.
I only rode a short distance before coming to a stop. I've been meaning to try a discarded old tire, running it flat to see if it's at all rideable at a slow speed, and to see if the beads finally pop loose, but I never get around to trying it.
~~~~
Those 23mm GP4000S measure 26mm on the 25mm rim. Unlike the comment above on the Mavic mounting difficulties, these are quite easy to mount. I do need a lever, but not much force on it. The beads don't pop into the bead seat until the pressure is fairly high, maybe 70-80 psi on these smaller tires.