Just installing a new GXP bottom bracket with my Truvativ GXP Firex Cranks, but cannot get the drive side crank to slide all the way in. Its as if there is a lip on the axle which doesn't fit the bearing.
There's nothing in the instructions about this, nor is there anything on the SRAM website. Has anyone here experienced similar problems?
there should be a gap between the spider and bb cup when the crank is all the way in. The crank spindle/axle rests up against the non drive bb cup from the inside, the non drive crank arm then 'pinches' the non drive bb cup from the other side. You should torque it to 50Nm. There is no preload on the drive side bearing like shimano/raceface etc. The crank instead is tightened onto the non drive bb cup.
OK, thanks.
I was suspicious because its quite a big gap (5mm at least) and it seems to affect the front shifting.
However I have changed from Shimano cranks to truvativ so that might explain why the shifting is out. Will have another go tomorrow...
CHeck there is no gap from chainset and BB on driveside. If there is...get a rubber mallet and bang her so she is flush. There shouldn't be too much of a difference in shifting between the two chainsets. The only dofference between the GXP and shimano is the axle diameter.
could be the chain line, you might need to play with the bb spacers, shift some over to the non-drive side or just leave them out
The chainline is 49/50mm, I'll need to check if that's acceptable but seems a little far out to me.
The rubber mallet made no difference, as sailor74 suggested, the non-drive side of the axle is hard against the inside of the non-drive side bearing, so no amount of malleting is going to help.
However, I reckon if I move the drive side spacer over to the non-drive side, this will sort it.
I'm selling the bike anyway, so just need to know its 'right' and will work properly, I'm not going to get too fussy beyond that.