I can't find a definate answer to this: are Race Face and Easton cinch-type chainrings cross compatible?
The splines/mounting pattern seems to be the same for both, but I've found someone saying that the offset is different
Anyone know anything more definite?
I believe they are yes, at one point I was going to get an Easton road double cinch spider to use RF cranks on my gravel bike. Don't know about offset but that would not be a surprise given the road/MTB target usage.
Yeah, I was going to get some for my bike - definitely Cinch -
https://eastoncycling.com/products/ea90-crankset?variant=29642162897005
(ended up going for Praxis in the sales as they're about half the weight)
Running a RaceFace 42t on Cinch cranks on my gravel bike, zero issues. Had a Superstar cinch ring on there briefly too
Raceface crank spindles are usually 136mm and 143.5mm (Boost) Easton crank spindles are 129mm. This allows all easton/raceface rings to be 3mm offset. All offsetting is done on the spindle not the chainring.
143.5 is not 'the' boost length. New RF axles are 136mm for boost but they used to be 134mm. 136mm gives 52mm chainline. The qfactor and chainline documents specifically references flipping the chain ring to adjust chainline.
143.5mm is an alternative for bikes with wide back ends. I've got one of those on my Tarn ti to give better heal clearance on the chain stays. It's gives quite a wide chainline (55.5mm I think).
Aftermarket rings have a variety of offsets with cinch mounts. On my Tarn I'm using a non-boost one up ring to move the chainline back in again.
There are also about 3 more longer sizes to accommodate superboost and fat bike.