Just fitted new GXP BB, and slotted in an old X9 crank.

Greased everything, and tightened everything up (as tight as i dare) but still a tiny bit of rocking at the pedals.

Stripped, regreased and tried again but still tiny amount of play. I have a torque wrench but no reducer to 10mm to torque it up exactly but I’ve tightened it up pretty hard.

Any ideas?

Are all the right spacers in place?

Yep, both black spacers (one each side) between frame and cups are in.

have you got both ‘end’ spacers in place? the tophat one on drive side and the one with the zig zags out on the other?

Yep, both seals/ spacers are in on both drive/ non-drive side.

Your not doing the bolt up tight enough 56nm will sort it.

It’s not just you, I found this a recurring issue with the 4 GXP BB’s I got through on my first year of mtb’ing. Realised in the end that I could buy a hollowtech 2 triple complete with BB for £100 from crc and never looked back.

Your not doing the bolt up tight enough 56nm will sort it.

this

Still got play. tightened to 54nM as per instructions – and still got movement in the crank!!!!

Bent crank?

Or crank too worn?

Not done the bolt up tight enough – its mega **** tight

Short term: add more grease, do it up real tight. Nope, tighter than that.

Long term: go and buy something reliable like HTII.

Is the HTII the shimano equivalent of a GXP?

Running a Bling Ring on an X-9 crank so need to run a GXP.

what frame are you fitting this to?

when done up to 56nm do you still have a 3-4mm gap on the driveside between the spider and bottom bracket top hat?

I have the 3-4mm gap on the drive side, should that not be there? Mine are rock solid though, i was surprised how tight it was.

The gap should be there.

If you have too many spacers in, you are effectively trying to pull the crank across to the angled bearing in the non-driveside. which can cause play

Hope BB with GXP conversion.
Either Crank is worn or return BB under warranty. That is your options

that, or put the correct spacers in. It would be hugely unlikely for a new bottom bracket to have “play” in it

a couple years ago the gxp bb’s were shipping and half of them had play from new.

we must have sent 5-6 back and all were warrantied.

there was a specific batch run with duff bearings which Sram published model numbers for voluntary return.

I remember that, at that point i was in their warranty department.

the chances of this BB being from a duff batch are low though

The two black spacers are in between the cups as it’s a 68mm Inbred bottom bracket. Top hat and wavy spacer is in.

There’s probably a 8mm gap on the drive side between the drive side cup and the back of the spider ring.

was advised by sram tech when I had this problem with a ceramic one I fitted and was told do the bolt up tighter it was 56 or 58nm, but yes tighter the=an specified on the bolt and it sorted it.

you holding the crank arms or the pedals when testing for play? 😉

Am holding the crank arms.

Will try going a bit tighter!!!

Give the drive side a tap with a wooden mallet or similar to make sure it is properly seated before tightening the non drive side. Also grease and more grease!