Hello all,
Just building up my new project and all was going well until I reached the cranks installation stage.
I have:
73mm bottom bracket shell
Shimano BB52 bottom bracket (MTB)
Bontrager GXP carbon cranks
So far I have:
Installed the BB with one spacer on the non drive side
Installed the cranks and tightened with quite a lot of force
But there is some side to side play with the cranks arms. With the cranks arms facing forwards and backwards horizonatally I can move them a few milimeters which feels completely wrong. I was under the impression that hollowtech 2 bottom brackets work with GXP cranks because they have the same spindle width?
Bottom bracket is new as I bought it today so not worried about bearings.
Cranks were bought off a guy second hand but don't seem overly used and not damaged.
Any help would be appreciated really as I am feeling a bit helpless.
TIA.
Nevermind just realised they aren't compatible. PITA.
Yes, you'll need a GXP bottom bracket.
Your Bontranger (Truvativ) GXP cranks aren’t going to work well with a Shimano HT2 BB - the drive side crank has a stepped 22mm spindle whereas HT2 is designed for 24mm. Also, the way that GXP is designed to take the axial load through the bearings is different - you can get a top-hat spacer that deals with the differences in diameter, but you may find that the BB bearings won’t last long.