- Feedback
- View
paulstottuk":2s971exn said:Thanks fluffychicken, please can you explain who trying to learn as well
Many thanks
Paul
Bare in mind these are way after my era of original knowledge, I am stuck in the M900 era of XTR

M960 use a minimal (or optimised) bolt circle diameter (i.e. where the holes to screw them to the crank arms arm). For the outside this is 146, current standard is 104 (middle and outer bolt together)
So that means the outer ring is not at any standard size but the M960 size, unfortunatly for these users Shimano haven't used it again or filtered it down to the lower groupset which renders it a very small market. So people just offer the default set
Set of ring here (M960)

compare that to a standar 4 arm outer
