I just bought a SRAM X0 2×10 crankset with GXP BB, but wanted to use it with the lovely Chris King BB that’s already is my frame.

However, upon installation, the axle on the SRAM cranks seems to be of a slightly smaller diameter than a Shimano HT II axle and the splines on the non-drive side seem to require the SRAM proprietary splined type washer from the non-drive-side cup on the GXP BB.

Checking SRAM’s website there’s no useful info at all (at least that I can find) on the axle diameter and BB compatibility.

Anyone know whether SRAMs GXP axle is compatible/incompatible with Shimano HT II type BB’s for definite, or have any technical documentation?

No sram and shimano use a completely different system, where the shimano is loosely compressed against both bb cups where the sram ones compress internally and externally on the non drive side cup only.

Chris King do do a version to fit sram crank sets but you wont be able to use your existing version

You can still use your Chris King BB. They do an adaptor that is basically just a shim and a couple of washers that fits around the end on the crank spindle to pad out the space.

When you buy a “SRAM” specific Chris King BB, it’s just the regular BB with the spacer included in the packet.

Contact you LBS and they should be able to get the adaptors for you from Evolution Imports (Chris King UK Dist)

You CAN fit SRAM GXP type cranksets into standard Chris King bottom brackets. All you need is one of these:

Chris King / SRAM GXP stepped axle converter kit:

I’ve got them fitted to both my bikes, and they work a treat. A bit confusing / fiddly to set up at first, as there are loads of different spacers they include in the kit, to suit a million different chainlines. However, once you get the right combination for your bike you will find that you don’t need half of what is included in the kit.

Cheers!