I’ve just bought a Noir crank, that I want to fit with an existing Hope bb…..however, ‘dry fitting’ it, it just doesn’t seem right…

The bb shell is 73mm (so one spacer fitted on the drive-side cup), but when I fit the r/h crank, the crank seems to sit too far inwards, to the point where there is a fraction of clearence between the outer ring and the chainstay, plus the mech cage is catching on the big ring when it shifts up/out.

So I could space the drive-side out to correct this, but then I’m concerned this won’t leave enough of the axle splines exposed, for the left-hand crank to attached on to.

Has anyone else faced similar problems? And how much (length in mm) of the axle splines have to be exposed, for the l-h crank to bolt on to?

Have you got a SRAM fit BB? They’re not the same as Shimano/FSA/RaceFace size wise!

http://www.bikeoutlet.co.uk/products/Hope_Truvativ_GXP_Bottom_Bracket_Adaptors_Convertor_Kit-761-34.html

I’ve got the Hope BB with the Hope GXP adaptors.

You won’t be able to space the driveside cup to move the chainset out, the axle floats in the driveside cup. It’s position is governed by the step on the axle butting up against the non driveside bearing, and clamping it with the crank. Probably a stupid question, but you have fitted both adaptors to the non drive side bearing, haven’t you?

You need the gxp hope adaptor shims for the bottom bracket. Chain reaction sell them for a Tenner. Hope video on you tube explains it all for ya

I haven’t actually fitted the GXP adaptors yet (I have also watched the Hope video). But thinking about it, when you fit the Hope shims, do they push the driveside out slightly by a few mm (thus solving my issue of the driveside crank being in to far)?

the hope adaptors fit to the non drive side so that wont help you. mine just sits up tight against the hope bb on the driveside.

not a great lot of clearance but enough i suppose.

The adaptors will help you as one fits either side of the non drive side bearing, thus pushing the step in the axle towards the drive side.

coatesy how can the adapters help when the hope GXP adapter fits to the non drive side?

both parts fit on the non drive side 1 internal and 1 external.

then you have 1 x spacer on your BB cup on the driveside. That is how mine is set up anyway.

Just fitted a Truvativ Noir chainset to a Hope BB with GXP adaptors in a 73mm shell this very evening. Two 2.5mm spacers on the drive side, none on the non-drive side, and everything seems to be working fine set up that way. 🙂

(I should to add, however, that I’ve not actually ridden this set up outside yet so it might all fall apart on me tomorrow. I’ll keep you all posted should any entertaining injuries ensue. 😉 )

[Edit: actually fitting the GXP adaptors to the NDS cup was a bit of a bugger, I had to lean on them quite hard to get them to pop in. You need to get them perfectly straight – using the chainset axle helps line things up.]

D’oh. Ignore me. Having actually watched the Hope video mentioned above, I went back and removed one of the 2.5mm spacers, as it wasn’t doing what I thought it was. And apparently you can wallop the adaptors with a hammer, that would have been useful to know too.

So, anyway: 1 x 2.5mm spacer on drive side, and the GXP shims in the non-drive side cup space it out correctly – this works for me in a 73mm BB shell. Sorry in advance if that doesn’t help much…

Tony 24, if you read my earlier post, you’ll see that the position of the chainset is governed by the non-driveside cup/step in the axle. Fitting the inner GXP spacer will move the axle’s step,and therefore the chainset too,towards the driveside by the thickness of the spacer.

Thanks everyone – I’m feeling happier now!