I want to buy a new 165mm cranked chainset for my Occam.
I'm going to buy an XT crank because I've already spent millions on the pissing thing and don't want to spend more and still end up with something cheopoer than the XT one that I'm replacing ( yes I know that makes no sense)
Do I buy a 55mm chainline, or a 52mm?
Are the chainrings interchangeable between XT and SLX? Looks like the SLX are £20 cheaper and since it'll wear out and need replacing before I sell the bike, I couldn't give a shit what's written on it.
Anyone using a 28tooth with a 51 rear? Any good?
( I know going to get roasted for even suggesting 28/51, but I spin really low gears and am currently finding that I spend most of my rides in bottom gear anyway (32t I think)
PS. I have googled this and come up with some answers/ opinions. But want to double check to be sure ( appreciate your help)
Well 52mm means a 135 or 142 back end and 55 is boost I think.
I just bought a 52mm slx crank inc ring for a good price from Merlin, but that was 32t and 175mm. They had best prices when I looked earlier this week, and I ended up buying a mix bag of bits to give me a new 12 drivetrain but no short cranks I could see just now .. and shout out to Merlin as it turned up very promptly..
My notes say ideal crankset chainlines for 1x:
non-boost 48-50mm,
Boost 51-53mm.
I think 55mm is superboost.
I just got the Shimano MT610 crank from Merlin with 52mm chainline for a boost frame myself.
As per OneUP Components website:
So what is Boost 148?
Boost 148 was created to give frame makers more design freedom for tire and front derailleur clearance. From a drivetrain perspective it moves the cassette 3mm away from the frame centerline. The new ideal chainline for Boost bikes is 51-53mm.
So I would suggest FC-M7100-1 or FC-M8100-1, as -2 is 55mm chain line.

Cheers!
I.
After a bit of checking I understand the 52m chain line will work with 135mm back end, which is good as that is the smallest Shimano do in their new 1 by chain sets. suggestion is 52 also works for boost, so must be some flexibility in it . If anyone knows better shout.
52mm is boost, 49 would be better for your set up as you'd get less rub etc. That said Shimano's cranksets are always quite wide chainlines, so any non-boost shimano chainset would likely be only a fraction off the new 52mm ones, which is why they dropped all the other chainlines from previous years I guess. So my advice is that 52mm will work, a 3rd party aftermarket ring that takes it down to 49mm would be even better.
Thanks for reply. Got a good deal on slx 52mm inc standard ring , lets see how it works..
Oh now I'm confused. No ideas which replies are to me and which are to Jerome.
52mm is what I need for the Occam, which comes with 148 boost wheels?
Also, are the SLX and XT direct mount rings interchangeable?
For the Occam yes 52. Slx and xt rings are interchangeable (as are xtr).
Thought I was helping 🙂
Hope you get sorted !
Same width for both of us and as said rings are Interchangeable
My slx ones seem lovely if you want to save a few £’s
Thanks all
Buy slx cranks - they are the same as the XT but cheaper and fit the chainring of your choice. The 12sp DM rings fit either crank.
Buy slx cranks – they are the same as the XT
and the logos don't wear off 12 seconds into the first ride.
