[Closed] GX cranks on PP Shan

Chainring is catching on the seatstay bridge.

Does not compute.

Oops. Chainstay bridge is what I meant

How is it catching chainstay bridge?

Bump for morning crowd. Tried now with two different chainrings (3mm & 6mm offset) still get contact on chainstay bridge. I'm using the gxp version with a hope press fit bb.

Maybe this will help explain better

[img] [/img]

I have a Shan that is 1x10 using a normal xt chainset. Its 32t ring and isnt anywhere near the DS chainstay. Which Shan is it? From memory mine has chainstays welded to the BB shell, not a machined piece prior to BB shell.

It's the Shan GT 29er. I had a set of XT cranks on previously which were fine so I might just have to stick them back on. Watched a few videos on GX crank installs and they all show a washer that goes on drive side which I don't have, not that I can see it making much difference.

What size is the chainring - it may just be too big. Also bear in mind the Hope GXP conversion gives a narrower chainline than the SRAM standard, which was already narrow, although I would expect that the 3mm offset ring would have fixed that. I assume you have the right spacers in the BB too?

32T chainring (3mm offset) so same size as my old XT mounted one. It does look like I need some spacers in there but which ones? XT cranks didn't need any spacers they fit ok but guess sram are different.

I have two 2.5mm spacers that are supposed to fit on 68mm BB shells but thought they wouldn't be needed on a pressfit BB.

Mine is the 650b version, so different. However im having a nightmare with a hope pf46 bb and a truvativ chainset on my dh bike....

If its pressfit you wont need spacers - the chainline/fit is based on the non driveside so spacers wont actually change the chainline.

Are your XT cranks Boost?

XT cranks are boost yeah and there's about 5mm clearance on chainstay bridge when using a 32t oval ring.

Do the GX eagle cranks do boost and non boost or is it just the chainring offset that changes chainline?

GX Cranks are all the same, boost depends on the chainring (or spider if not direct mount) offfset for SRAM

Your XTs would have about 3mm more than the GXP in terms of clearance - then account for whatever the oval ring might add / change and its possible, assuming that maybe you're remembering 5 but its actually a bit less and it could work out.... but a 32T oval is 34 equivalent at the high point, so you'd expect even with the difference in chainline it would still work out.

Do I possibly need a hope bb to gxp converter cup?

I've ran none boost xt on gt with 30 t ring but needed a small spacer behind crank and BB as without it would not work . ( race face cranks use the spaces )

Do I possibly need a hope bb to gxp converter cup?

There's no such thing. You need these spacers though

[img] [/img]

Otherwise there's nothing to stop the NDS axle, and hence it'll go right through and you'll end up with your chainring in the position your's is in.

Thanks [b]davidtaylforth[/b] that's the spacers I was wondering about. Problem hopefully solved. Cheers.