Originally Posted by
the sci guy
Thanks for this.
The BB is 68 and the rear width is 135 (see pics). Since my plan is to remove the triple chainrings and put in a single one, it’s safe to assume the recommended spindle width might be a tad short since going single chainring makes the whole apparatus smaller so I’d need maybe 2 more mm of spindle to account for it? Am I thinking about that correctly?
You should be fine with the middle position. Triples are set to hit the middle of the cassette, or very close to it from the middle ring. I don’t see any problem running the whole cassette with a 1x.
Don’t worry about chain angle with a 9 speed. People are running 1x11 and 1x12, as designed with more severe angles, without issues. It’s funny, I heard about the perils of cross-chaining with a 2x6 decades ago.
John