I’m looking to get a shorter length crank, and rather than replacing the BB I thought I would just get the same cranks but shorter.

They currently use the PF92 BB, but the cranks I can find are now DUB fit and use the DUB PF92 BB. Anyone know if these are backward compatible with the non dub BB?

If I need a new BB I might just looke elsewhere for cranks, but was looking at doing it the simple way!!

No, they’re not. The able is a different diameter. It’s the new standard to replace the one standard, and it’s better, obviously.

As above, the DUB cranks are not compatible with anything other than the specific DUB BB’s. Surely there’s GXP Sram/Truvativ still available in the length/model you want somewhere? I picked up a set of  newer style GXP Stylo carbon cranks dirt cheap recently

Been having a look to see if I can get the same cranks – they are Truativ Eagle ones, but so far can only find the DUB ones!

I have been looking at the SRAM website but cant see that any of the other cranks will work with my current BB – which is the PF92 (BB89/91.5 with 24mm spindle)

My current cranks are:

SRAM Descendant 6k Eagle, 32T Direct Mount X-Sync

Would these fit my BB? Or do they require a different BB?

https://www.evanscycles.com/sram-eagle-gx-gxp-boost-chainset-with-32t-chainring-EV311542

I’m so not clued up!!

When I look on the SRAM website they are compatible with some of the same BB’s.

So according to Sram website…

Descendant Eagle that I have is compatible with

BB30/PF30-68/73mm, GXP/PF GXP 68/73mm

And the GPX ones are compatible with

BB30/PF30-68/73mm, GXP 100mm/PF GXP 121mm, GXP/PF GXP 68/73mm

But according to Trek my BB is PF92 BB89/91.5 which does not match either of the above including what I already have 9 on the bike. So confused!!

The PF92 bb’s use a 24mm axle spindle, instead of PF/BB30 which has a 30mm spindle. THE GXP cranks you linked to will work. You can get PF92 BB’s to work with shimano or gxp cranks.

<span style=”text-decoration: underline;”>The PF92 bb’s use a 24mm axle spindle, instead of PF/BB30 which has a 30mm spindle. THE GXP cranks you linked to will work. You can get PF92 BB’s to work with shimano or gxp cranks.</span>

Excellent – so the GXP ones I listed will just be a simple straight swap for the Descendant ones and no need to change anything else?

Those ones you’ve linked to are Boost, which just means the chainline is slightly farther out, you don’t say if your current frame is boost or not.

GXP is 24mm with a 22mm step at one end to clamp the NDS bearing.

BB30 is 30mm (I’ve never had one so have no idea if how SRAM implement it in a GXP style).

DUB is somewhere in between (meaning it’s stiffer than a 24mm axle, but can still fit in a normal threaded BB shell.

.

Yeah its boost – Trek Fuel 2018