Compatibility standards
The bike component standards we track, grouped by category. Open a standard to see what it is (and isn't) compatible with, and the related questions.
Freehub bodies & cassettes
Shimano HG (Hyperglide) 8–11s The most widespread splined freehub body. The standard for Shimano/SRAM cassettes from 8 to 11 speeds (with some distinctions). SRAM XD Driver 11–12s MTB A dedicated body for SRAM cassettes that start at 10 teeth (MTB), e.g. 10-50 / 10-52. SRAM XDR 12s road/gravel An XD variant that is 1.85 mm wider, for road/gravel (10t cassettes, e.g. SRAM 12-speed AXS Flattop). Shimano Micro Spline 12s MTB A body for Shimano 12-speed MTB cassettes (10-tooth start), e.g. XT/SLX/Deore M7100/M8100. Campagnolo / Fulcrum N3W 12–13s A recent Campagnolo body for 12/13-speed cassettes (9-tooth start).
Chains & speeds
Shimano 12-speed (HG+ / Hyperglide+) 12s Shimano 12-speed chain/cassette. The road lines (105/Ultegra/Dura-Ace 12-speed) and MTB lines use dedicated chains. SRAM Flattop (12-speed AXS road) 12s road AXS A proprietary SRAM chain for 12-speed AXS road groupsets (Red/Force/Rival): taller, with different links. 11-speed chains (road) 11s The 11-speed chains from Shimano, SRAM and KMC are effectively interchangeable with one another on 11-speed drivetrains.
Bottom brackets & frame
BSA / English threaded (68/73 mm) A threaded bottom bracket shell, 1.37" x 24 tpi. The most reliable and quietest standard. PressFit BB86 / BB92 Press-fit shells: BB86.5 (road, Ø 41 mm) and BB92 (MTB, ~91/92 mm). BB30 / PF30 30 mm spindle standards: BB30 (direct-fit bearings, Ø 42 mm) and PF30 (bearings in pressed cups, Ø 46 mm). T47 An oversized threaded shell (47 mm thread): the reliability of threading with the width of PF30. SRAM DUB (crank spindle) DUB is a crank SPINDLE standard (28.99 mm), not a shell: DUB cranksets fit many shells with the right DUB cup.