I'm fitting a Rohloff this weekend and will need to find a way to get a 57mm chainline out of my direct mount cranks (RF Turbines)
My bb shell with is 68mm, so that gives me some room to play with if I don't put the recommended 2.5mm spacers behind each bb cup and instead use 30mm diameter spacers on the spindle itself
I assume there's no problem doing that, even if I end up putting all the spacers on one side and running the cranks a couple of mm off centre?
Probably not, but I'd imagine its preferable to have the loads from pedaling as close to the bearings as possible. You might screw the BB quicker
I’ve done the same on my G16 with a 68mm BB, one less on the spacer BB and one extra on the crank. (Raceface Atlas).
I just had to swap off a Raceface crank I bent last week and stuck a shimano one one. (eBike/Shimano motor)
The RF one had a 4.7mm spacer behind it I had to take off or the Shimano crank wouldn't go on so as long as you get enough spindle to clamp onto it would seem legit
Probably not, but I’d imagine its preferable to have the loads from pedaling as close to the bearings as possible. You might screw the BB quicker
Yes, that's what I was thinking. I guess I may be able to work something out even with spacers behind the bb
Flip the chainring. That will give you 57.5 chainline.
@benpinnick yes, I'm def flipping the chainring and hoping that will get me close (although it's an Absolute Black 42t ring, and I'm not sure the offset is the same as the RF rings)
I'd prefer to space the BB (maintaining the right space between bearings) rather than space the axle. The cranks tend to have a reasonable shoulder on the axle for the bearing to sit on, but it's really only to take up variations in manufacturing tolerance.
use these: https://www.chainreactioncycles.com/nukeproof-horizon-bottom-bracket-spacer/rp-prod190755
once you've flipped the chainring.
Spacing the cranks is pretty standard on Hope 30mm and Sram DUB BBs