[Closed] Removing 'play' from SRAM XO GXP cranks. I can't get them wobble free!!! Argghh

Spacer between cup and frame will have absolutely no impact on GXP.
I'd be trying a new BB.
When my GXP BB is worn out, I'll be going for a Hope one with the GXP adapter.

What BB are you using? If you've just used the BB that came with the bike, and it's not a SRAM GXP compatible one you'll get the symptoms you're describing. GXP cranks require a GXP-specific BB, you can't just use a standard 24mm one. The NDS bearing is narrower and the crank and spindle cinch down onto it to hold the whole thing together.

If it *is* a GXP BB then it's probably just ****ed. 😉

Thanks guys.

It is a GXP b/b.

I am also thinking of ditching the SRAM crap and buying another brand (HTII type) with an adaptor.

Cheers,

Depending on which BB (PF30 and others) there's a pre-load adjuster. You'll get wobble if it's not nipped up once the cranks are in.

See number 8 on PF30 diagram in the [url= https://sram-cdn-pull-zone-gsdesign.netdna-ssl.com/cdn/farfuture/snnI1oIViW6wtrUobgMXxEltrlGx1MEI9D_06KiyI5Y/mtime:1399306711/sites/default/files/techdocs/95-6115-006-000_rev_g_mtb_cranksets.pdf ]manual[/url]

Have you got the wavy silver washer installed on drive side, its shown in the link above on the gxp press fit diagram.

what torque setting are you tightening them to? Sounds like they arent tight enough

It's a GXP so a traditional screw in type. I don't think there is a reference to any other washers for this type- only press fit stylesc

I have a digi-torque wrench and am actually torquing just past the stated value on the bolt itself. There literally is no way of cranking any more- I'm afraid the bolt will let go.

is the black plastic top hat present in the drive side bearing, and the splined washer on the non driveside?

Measure your BB shell width; make sure it is 73mm. If it isn't (my guess is it might be a bit wider) then you'll need to get a bit taken off it.

Thanks guys. B/B is complete with both bearing covers/washers.

I've not physically measured the frame and would be reluctant to face it as its all covered in the same paint as the carbon around it. It worked fine with shimano so if needs be I'll go back to that.

Cheers

GXP is either tight or not, assuming that you got the crank all the way onto the splines so that it is tight on the NDS (there should be no gap) then you're done. Any play from there is the BB. So the thing to check is whether the axle and NDS crank are making a tight fit onto the NDS bearing. Firstly when you insert the crank from the drive side does it go in and then butt up against the NDS bearing, leaving a 2mm (or so gap) on the drive side between the bearing and the crank arm. Once in fully most play should be gone already. If its still wobbly then either the cranks not in fully or the bearings are shot. Then when you put the NDS crank on you should be able to do it up until its totally snug on the NDS BB. If theres a gap then you have a problem. Assuming the drive side went in ok as above, and the NDS snugs right up tight, then its pretty much guaranteed its the bearing.

EDIT I should point out that this is for a standard threaded BB - press-fit might need some spacing out maybe, although I cant really see why.

I have around a 2mm gap between the DS crank spider and the B/B bearing cover. There is no gap on the NDS.

I'm baffled but a new b/b is the next port of call

This is basic engineering, if you have side to side play on both crank arms your bearings are foobar, even if you have a gap between bearing face and crank there should still be no sideways play on the cranks only lateral play if you push or pull the cranks towards or away from you, if the non drive side isn't snugged up properly then you will have play only on that side.

Basic engineering maybe, but rather mind boggling none the less. I've had it confirmed its a month old B/B so it's not that.

An axle through this type of bearing could have play on the axle if there isn't any preload so I can't agree with your statement there.

Anyway, I've sorted it now with a spacer from some other cranks- totally off plan but it worked.

Cheers all

I take it you put the spacer between the NDS crank and the BB? If so worth taking them off again and greasing the splines on the crank and trying again on the NDS crank without the spacer. Ive see some cases where a crank feels 100% tight on but its actually binding on the splines, not fully tight onto the BB bearing.

Yes as you describe buddy. Running no spacers now though. I'm using one off some raceface cranks- a small 1mm rubbery one on the axle by the chainring. It's all tightened up fine now.

Cheers

I have same issue with a new sram gxp screw in BB.

Only slight play but it's there.

Going to strip it down soon as have some new cranks to go on anyway.currently has stylo cranks running a n/w chain ring.

I suspect the new bb is at fault but I might be wrong.

Some good info on this thread, so will refer back to it when I replace the cranks with the Gx1000's!

I had exactly the same "play" when installing some XX1 GXP cranks on my Transition.

Found some installation videos on YouTube - basically you have to give the drive side a good old whack with a rubber mallet then tighten the non drive side crank arm far more than you think you should!

Apparently when questioned SRAM confirmed this is the correct "teqnique"

I'll try that. Thanks pal

yup, had the same issue when i first got XX1 cranks years ago, took it to the LBS, they just tightened it up more