Cassette and freehub body: the complete compatibility guide

Why is it so complicated?

There was a time when there was only one freehub body standard. That time is over. With the multiplication of speeds (10s, 11s, 12s, 13s) and competition between manufacturers, we now have six main standards that are not interchangeable.

Order the wrong cassette for your wheel and you are guaranteed a trip back to the shop. Here is the guide to never getting it wrong again.

The 6 freehub body standards

Shimano HG (HyperGlide) — The original standard. Compatible with Shimano and SRAM cassettes from 7 to 10 speed. The splines are wide, the body measures about 35 mm long. This is the body found on 90% of entry-level and mid-range wheels.

Shimano HG+ (HyperGlide+) — Identical to HG in dimensions, but with one wider spline to handle the torque of 11 and 12-speed cassettes. HG+ cassettes are backwards compatible with standard HG bodies, but they dig into aluminium bodies more. Shimano recommends a steel body for HG+.

Shimano Micro Spline — The new Shimano standard for 12-speed cassettes (M7100, M8100, M9100). The 10-tooth smallest cog requires a smaller body with micro-splines. Incompatible with HG/HG+. Mandatory for Shimano 12-speed.

SRAM XD — The SRAM standard for cassettes with a 10 or 9-tooth smallest cog (XX1, X01, GX Eagle 12s). The smallest cog threads directly onto the body. Incompatible with HG and Micro Spline.

SRAM XDR (XD Road) — Road version of XD, 1.85 mm longer to accommodate SRAM road cassettes (Red, Force, Rival 12s). Also compatible with XD MTB cassettes using a spacer. Note: a standard XD body does NOT accept XDR road cassettes.

Campagnolo — Proprietary standard. Campagnolo bodies have a unique spline profile, incompatible with everything else. Required for Campagnolo cassettes (Record, Chorus, Centaur). Campagnolo N3W is the new 13-speed standard, different from the old one.

The compatibility chart

Important: a Shimano 12-speed SLX/XT/XTR cassette does NOT fit on a standard HG body. You need a Micro Spline body. However, a Shimano Deore 12-speed cassette (M6100) fits on HG+.

Adapters: solutions and limits

The good news: most hub manufacturers offer interchangeable freehub bodies. DT Swiss, Hope, Industry Nine, Chris King... You can often switch from one standard to another by simply changing the body.

• DT Swiss: conversion kits for HG, Micro Spline, XD, Campagnolo, SRAM XDR
• Hope: interchangeable bodies on Pro 4 and Pro 5 hubs
• Mavic: ID360 system with interchangeable bodies
• Fulcrum / Campagnolo: adapters depending on model

The limits: some entry-level hubs have a fixed (non-interchangeable) freehub body. In that case, you need to change the entire wheel to switch standards.

Common traps

• "12-speed" does not mean "compatible" — a SRAM Eagle 12s cassette (XD) and a Shimano XT 12s cassette (Micro Spline) do NOT fit the same body
• HG 11s vs HG 10s — an 11-speed cassette needs a slightly longer HG body (1.85 mm). Most modern wheels are compatible, but older 8/9/10s wheels may not be
• The forgotten spacer — fitting a 10s cassette on an 11s body without the 1.85 mm spacer means the lockring does not tighten properly

How L'Atelier helps

You have a wheel and want to know which cassettes are compatible? Or you have a cassette and need the right body? Ask:

"Which freehub bodies are compatible with the Shimano CS-M8100 12-speed cassette?"

The assistant finds the sourced answer in the technical documentation.

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