What is SRAM GXP?
What is GXP?
We’ve been getting a lot of questions about GXP, so here’s a quick primer. GXP stands for Giga X Pipe, originally developed by component maker TRUVATIV (acquired by SRAM in 2004). SRAM adopted the standard across many of its cranksets.
What makes GXP different?
Shimano Hollowtech II and SRAM GXP both use external bottom bracket bearings with a smaller-diameter spindle than 29/30 mm systems. The key difference is spindle diameter:
Hollowtech II uses a constant 24 mm spindle across its length.
SRAM GXP uses a tapered spindle—24 mm on the drive side to 22 mm on the non-drive side. The taper is on the splined portion of the spindle, not the smooth center section.
Different spindles mean different bearings
- Hollowtech II: 24 × 37 × 7 mm bearings on both sides.
- GXP: 24 × 37 × 7 mm (drive side) and 22 × 37 × 8 mm (non-drive side).
With a constant 24 mm spindle you can often adjust chainline with crank spindle spacers (the spindle slides through both bearings). With GXP, the taper bottoms on the non-drive bearing, so moving the crankset inboard typically requires bottom bracket cup spacers.
Bottom line: GXP’s 24 → 22 mm taper is the defining feature. When in doubt, measure—correct spindle and bearing sizing makes all the difference.
