Cranks don't turn

Coxy_UK

So replaced Gxp bb with Hope one using adapters. X0 crank says tighten to 48-54nm, if I tighten anywhere close to that the cranks barely turn. What should I be tightening to please?

Hope bb comes with 2.5 mm spacers and for 73mm shell says just put one drive side, I have.

Should I be z doing different?

Coxy_UK

I didn't do it up that mind, sounds way too much. Done to 12nm and feel no play and if I push pedals round backwards and let go they do about a turn and a half if that makes sense

nicklouse

sram done not use any spacers on the drive side for a 73mm BB

as the cranks are positioned by clamping the ND bearing and the drive side is free to just spin.

so with a spacer you are crushing the bearings when the bolt is tight and not tightening the bolt enough when the bearings will spin.

Ouija

+1

The whole GXP system revolves around preventing you from being able to side load the bearings. It does this with a axle that drops down from 24mm to 22mm on the non drive side. The two adapters that come with Hope BB's are to ensure that the back of the non drive side bearing cup presses up against the point in the axle where it drops from 24mm to 22mm. That adapter and the one on the other side of the same cup meet up in the middle of the cup and physically prevent you from crushing the bearings on the non drive side. And since the inside adapter is pressing up against the drop down from 24mm to 22mm on the axle, simultaneously prevents you from being able to pull the entire drive side spider and arm against the drive side cup with any force.

Obviously, if you've jammed a spacer in there, then you've guaranteed that the back of the adapter on the non drive side isn't pressing up against the 24 to 22mm lip on the axle, allowing you to pull the spider on the drive side firmly up against the cup allowing it to seize up.

Remove the spacer. There should be no spacers on a 73mm bottom bracket shell.

Coxy_UK

No the spacer just goes between cup and frame, without it the bb cup is like half a mm from frame.

I think my problem was plastic bit on crank spindle. Its been crushed and on inspection says gxp on it so I assume this was part of the original bb and should of been removed anyway!

Will report back in a min

Coxy_UK

Done and torque to 68 ft lbs and free spins nice with no play. In short, I'm an idiot.