GXP clone BB, what fits?

[Joe Remi]

I picked up a Breezer Doppler gravel bike from the Performance Bike closeout sale yesterday. The cranks are too long for me at 172.5mm so I pulled them and the BB and tried a Sugino crank with square taper BB, but the chainline isn't great.

I'm used to working with square taper cartridge BBs with different spindle lengths, these outboard bearing things are a bit of a mystery to me. The bike came with an Oval Concepts 300 crank and "SRAM GXP clone" BB (73mm threaded shell), how do I determine what new cranks would fit my BB cups?

[bikinchris]

Well, any SRAM or Truvativ crankset currently made will work with that bottom bracket. If installing a new bottom bracket on a 73mm frame, do not use the two spacers that come with it. Those are for 68mm wide bottom bracket shells.
Shimano cranks won't fit. They use the same size spindle on both sides. The GXP has a slightly larger ID on the crank side bearing.

[Joe Remi]

Great, thanks Chris! That info probably should be self evident, but I'm reeeeally slow to grasp new (to me) bike tech.

[Mark McM]

Well, any SRAM or Truvativ crankset currently made will work with that bottom bracket.

That isn't quite true. SRAM and Truvativ make many cranksets with BB30 (30mm) spindles that won't fit a threaded BB shell. Only SRAM and Truvativ cranksets with GXP or DUB spindles will fit. In addition, while many gravel bikes use road cranksets, SRAM GXP road cranksets only fit 68mm threaded BBs, not the 73mm BB on this frame.

[BikeNY]

That isn't quite true. SRAM and Truvativ make many cranksets with BB30 (30mm) spindles that won't fit a threaded BB shell. Only SRAM and Truvativ cranksets with GXP or DUB spindles will fit. In addition, while many gravel bikes use road cranksets, SRAM GXP road cranksets only fit 68mm threaded BBs, not the 73mm BB on this frame.

I think that's all true, except I thought DUB used a different spindle diameter? He's asking what will fit in his current BB cups.

So it sounds like only SRAM and Truvativ GXP mountain cranks will work.

[Bentley]

So the OP asked about a GXP bottom bracket and I am unaware of a GXP that takes a 30mm crank. I believe that a GXP BB is a 24mm. I believe Praxis makes a viable GXP compatible BB. Apologize if I misunderstand the original post.

[charliedid]

I wouldn't let a $25 BB be the deciding factor for which cranks you buy. 73mm threaded BB will take a host of cranks and BB including Shimano,Race Face, FSA and others.

That said, others are right, that is a SRAM/Truvativ 22/24mm BB so all the ATB cranks form them obviously work with the current cups.

What's Performance have on closeout?

[Joe Remi]

I wouldn't let a $25 BB be the deciding factor for which cranks you buy. 73mm threaded BB will take a host of cranks and BB including Shimano,Race Face, FSA and others.

That said, others are right, that is a SRAM/Truvativ 22/24mm BB so all the ATB cranks form them obviously work with the current cups.

What's Performance have on closeout?

Yeah, you're right about not insisting on reusing the cups, I didn't realize last night how cheap/disposable they are. I'm new to the outboard bearing thing.

Performance is closing out everything.
If you have a store near you, get there pronto.

[RudAwkning]

By definition, GXP is the 24mm SRAM spindle size and is steel. The BB will have 24mm on the drive side and 22mm on the non-drive. There's no preload on this system either. The 24mm axle simply bottoms out into the 22mm non drive cup.

BB30 is 30mm and uses an aluminum spindle.

The new DUB system is 28.99mm, aluminum, and replaces both GXP and BB30 in the SRAM lineup. They did this to primarily simplify their lineup, but also to squash the complaints of folks running BB30 cranksets in BB92 pressfit shells and having their bearings die a few months later. A 42mm shell and a 30mm axle doesn't leave a lot of space for bearings! Allegedly, you get the weight savings of BB30 with the lifespan of GXP now.

[bikinchris]

That isn't quite true. SRAM and Truvativ make many cranksets with BB30 (30mm) spindles that won't fit a threaded BB shell. Only SRAM and Truvativ cranksets with GXP or DUB spindles will fit. In addition, while many gravel bikes use road cranksets, SRAM GXP road cranksets only fit 68mm threaded BBs, not the 73mm BB on this frame.

I had originally mentioned the 73mm shell width, but removed it on an edit. Thanks, for mentioning it.