Originally Posted by
PatrickGSR94
That is surprising. It would only hold true to a certain point, though. If you tried to put it on a wide 29er rim it would have to be shorter at the center. Just think of a section of folding bead tire when folded flat, it's as short as it can be, and the beads are as far apart as they can be.
After a certain point, it would get shorter at the centre. However, that would be a very wide rim for a tyre width. Like 23 mm wide inner rim bead width with a 23 mm tyre.