Freehub Body Types: Will Your Cassette Fit? (Chart + Checker)
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A cassette fits your wheel only when it matches the freehub body’s spline pattern and its length. There are four families: Shimano HG (in a mountain length and a longer 11/12-speed road length), Shimano Micro Spline, SRAM XD/XDR and Campagnolo. A cassette from one family never fits a body from another, spacer or not. Inside a family, a 1.85 mm spacer covers exactly two cases: an XD cassette on an XDR body, and a mountain-length HG cassette on a road-length HG body. Pick your body and the cassette you want below for a straight yes or no.
Cassette fit checker: will it go on your wheel?
How the checker works: every answer comes from the chart below, which is built from Shimano’s 12-speed freehub guide, SRAM’s XD/XDR explainer and SRAM’s 2024 road compatibility map. Cassettes not on the list (Shimano CUES, SRAM Eagle Transmission, third-party brands) are left out because we couldn’t confirm them from a maker’s own document; check the cassette’s spec page for its freehub type.
Freehub compatibility chart by cassette model
Find your cassette’s model number (it’s printed on the largest cog or the box) and read across. “Spacer” always means one 1.85 mm spacer installed behind the cassette.
| Cassette | Fits as-is on | Fits with a 1.85 mm spacer on | Won’t fit |
|---|---|---|---|
| Shimano / SRAM 8, 9, 10-speed | HG, MTB length | HG, road length (SRAM: all 8/9/10-speed)* | XD, XDR, Micro Spline, HG L2, Campagnolo |
| Shimano 11-speed MTB; CS-HG800 and CS-HG700 11-34 | HG, MTB length | HG, road length | All others |
| 11-speed road (Shimano road; SRAM PG-1170, PG-1130, XG-1190) | HG, road length | None | HG MTB length and all others |
| Shimano 105 R7100 / Ultegra R8100 12-speed | HG, road length | None | HG L2, Micro Spline, XD/XDR |
| Shimano Dura-Ace CS-R9200 12-speed | HG L2 and HG road length | None | Micro Spline, XD/XDR |
| Shimano 12-speed MTB (XTR M9100, XT M8100, SLX M7100, Deore M6100), also used by GRX 1×12 | Micro Spline | None | HG (either length), HG L2, XD/XDR |
| SRAM Eagle XG-1299, XG-1295, XG-1275 (10-52 / 10-50) | XD | XDR | HG, Micro Spline |
| SRAM NX / SX Eagle PG-1230, PG-1210 (11-50) | HG, MTB length | HG, road length | XD, XDR, Micro Spline |
| SRAM 11-speed MTB XG-1199, 1195, 1180, 1175, 1150 (10-42) | XD | XDR | HG, Micro Spline |
| SRAM 12-speed road/gravel XG-1290, XG-1270, XG-1250, XPLR XG-1271 / XG-1251 | XDR | None | XD, HG, Micro Spline |
| SRAM PG-1231 11-44 (12-speed) | HG, road length | None | HG MTB length, XD/XDR |
| SRAM XG-1391 13-speed (10-46) | XDR | None | XD, HG |
| Campagnolo 9 to 12-speed | Campagnolo | N3W with Campagnolo’s adapter kit (not a 1.85 mm spacer) | All Shimano/SRAM bodies |
| Campagnolo 13-speed (Ekar) | N3W | None | All others |
Two rows in that chart catch a lot of riders out. First, Shimano 12-speed road cassettes don’t need a new wheel: Shimano says its HG freehub takes both 11- and 12-speed road cassettes, so a 105 R7100 or Ultegra R8100 cassette goes on the same road wheel your 11-speed cassette came off. Second, budget SRAM Eagle (NX and SX, PG-1230 and PG-1210) was made for the ordinary HG body, so a lot of older mountain bikes can go 12-speed without an XD driver.
How to tell which freehub body you have
The fastest route is the hub’s model number: look it up on the maker’s site and the spec sheet will name the driver. If the hub is unmarked, pull the cassette with a Park Tool FR-5.2 lockring tool (or the FR-5.2GT for thru-axle hubs) and a Park Tool SR-12.2 chain whip, then check these in order:
- Is there a visible lockring? SRAM XD and XDR cassettes thread onto the driver, and Park Tool notes their lockring is hidden down inside the cassette stack. If the whole cassette unscrews as one piece, you have XD or XDR. A road-spaced wheel will be XDR, which SRAM says is 1.85 mm longer than XD and sits in the same space as an 11-speed road HG body.
- Count the splines. Shimano counts 9 effective splines on HG, with one wider gap so the cogs only go on one way (Park Tool tells you to look for that wide space). Micro Spline has 23 narrow splines. HG L2 has 18 small, deep splines and only shows up on Dura-Ace 12-speed wheels; it looks like Micro Spline, but it isn’t. Campagnolo bodies use eight splines of different shapes.
- If it’s HG, check the length. Slide on an 8/9/10-speed or 11-speed MTB cassette and snug the lockring. If the cogs still shift side to side, the body is the longer road version and that cassette needs the 1.85 mm spacer.
Why a spacer only works in two cases
A spacer fills length. It can’t change spline shape. SRAM’s own explainer tells you which lengths line up: the XD driver keeps “the same hub spacing and flange locations used for 8, 9, and 10-speed” HG bodies, and XDR keeps the spacing of the 11-speed road HG body. So the two “short” bodies (HG MTB length and XD) are equal, and the two “long” ones (HG road length and XDR) are 1.85 mm longer. That gives you exactly two spacer moves:
- XD cassette on an XDR body: 1.85 mm spacer behind it (SRAM). The reverse, an XDR cassette on an XD body, won’t fit because the body is too short.
- Mountain-length HG cassette on a road-length HG body: 1.85 mm spacer (SRAM’s map for its 8/9/10-speed cassettes; Shimano for its 11-speed MTB, CS-HG800 and CS-HG700 cassettes). The reverse doesn’t work: an 11-speed road cassette won’t fit an MTB-length body.
The same reasoning tells you which conversion a wheel can take. A mountain wheel built around an 8/9/10-speed HG body is spaced like XD, and a road wheel with an 11-speed HG body is spaced like XDR, which is why SRAM says XD and XDR work without new axle standards or hub redesigns, and why many hub makers offer more than one driver for the same hub. A Shimano 1.85 mm low spacer costs little, but it’s the only part that bridges the length gap.
Common upgrades: what you actually need
| You have | You want | What to do |
|---|---|---|
| Road wheel, Shimano 11-speed cassette | Shimano 105 / Ultegra 12-speed | Nothing: the same HG road body takes it (Shimano). |
| Road wheel, Shimano 11-speed cassette | SRAM AXS road 12-speed (XG-1270 etc.) | An XDR driver for your hub, or a new wheel. SRAM’s PG-1231 11-44 is a 12-speed option that stays on HG. |
| Mountain bike, HG body, 10 or 11-speed | 12-speed SRAM Eagle on a budget | NX/SX Eagle PG-1230 or PG-1210: fits the HG body as-is. |
| Mountain bike, HG body | Shimano 12-speed (Deore to XTR) | A Micro Spline driver for your hub, or a new wheel. |
| Gravel wheel with XDR | SRAM Eagle 10-50 / 10-52 (mullet) | Fits with a 1.85 mm spacer behind the cassette (SRAM). |
| Older road wheel, 8/9/10-speed HG body | 11-speed road cassette | Won’t fit. Use CS-HG800 or CS-HG700 11-34, or replace the wheel or body. |
Changing cassettes across brands or speeds usually changes the chain and derailleur requirements too. Check the right chain length for the new range, and re-index afterward using our rear derailleur indexing guide.
Swapping a driver body: what to check first
- Match the exact hub model, not just the brand. Santa Cruz’s rider support team points out that Industry Nine Hydra and 1/1 hubs use different bodies, and DT Swiss star-ratchet hubs (180, 240, 350 and newer 370) don’t share a body with the older three-pawl 370.
- Brand-owned wheels may be limited. Performance Bicycle notes that a Shimano wheelset will probably only have Shimano HG or Micro Spline bodies available, so moving it to XD may not be possible.
- Many bodies pull off by hand once the cassette and end caps are off. bike-components names Hope and DT Swiss among the makers that allow tool-free swaps, but follow your hub’s own procedure.
- Torque the lockring. Park Tool’s general figure is at least 40 Nm (354 in-lb), or whatever the cassette maker specifies. A bicycle torque wrench that reads to 40 Nm takes out the guesswork.
If the new cassette fits but the chain still jumps under power, the freehub isn’t the problem. Work through our chain skips under load guide, and check chain wear with our guide on when to replace a bike chain: a worn chain will skip on new cogs.
Mistakes that cost riders a return shipment
- Assuming “12-speed” is one standard. Shimano 12-speed road uses HG, Shimano 12-speed MTB uses Micro Spline, SRAM 12-speed road uses XDR and SRAM Eagle uses XD, except NX/SX, which use HG.
- Buying HG L2 parts for a Micro Spline wheel (or the reverse). Shimano’s HG L2 takes only Dura-Ace 12-speed cassettes. The fine splines look similar, but the two bodies aren’t interchangeable.
- Forgetting the spacer on CS-HG800 / CS-HG700. These 11-34 cassettes are sold for 11-speed road groups but are MTB length, so Shimano calls for a 1.85 mm spacer on a road HG body.
- Expecting a spacer to fix a spline mismatch. It can’t. If the chart says “won’t fit”, the answer is a different driver body or a different cassette.
Freehub FAQ
Will a 12-speed cassette fit an 11-speed freehub?
It depends on the cassette. Shimano 12-speed road cassettes (105, Ultegra, Dura-Ace) fit an 11-speed road HG body, and so does SRAM’s PG-1231. SRAM NX/SX Eagle fits an HG mountain body. SRAM AXS road cassettes need XDR, SRAM’s higher-end Eagle needs XD, and Shimano 12-speed mountain cassettes need Micro Spline.
Can I put a 10-speed cassette on an 11-speed hub?
Yes, with a 1.85 mm spacer behind the cassette. SRAM says this works for all its 8, 9 and 10-speed cassettes. Some Shimano 10-speed road cassettes also call for a 1.0 mm spacer, so check the instructions that came with yours.
Is XD the same as XDR?
They share the thread-on interface, but XDR is 1.85 mm longer. XD cassettes fit XDR with a 1.85 mm spacer. XDR cassettes don’t fit XD.
Will a Micro Spline cassette fit an HG freehub?
No. Micro Spline (23 splines) and HG (9 splines) are different shapes, and no adapter or spacer changes that. You need a Micro Spline driver for your hub or a different wheel.
Can a Shimano cassette go on a SRAM XD driver?
No. XD and XDR take only thread-on cassettes made for that interface. A Shimano HG cassette needs an HG body, and a Shimano 12-speed MTB cassette needs Micro Spline.
Still hearing noise or feeling drag from the hub after the swap? See our rear hub diagnosis guide.
Sources
- Shimano: A Guide to SHIMANO’s 12-Speed Freehubs and Compatibility
- SRAM: SRAM XD and XDR Driver Body Explained and Road Compatibility Map 2024 (PDF)
- Park Tool: Cassette Removal and Installation
- bike-components: Freehub and freehub body: function, compatibility and conversion
- Performance Bicycle: Which Freehub Do I Need?
- Santa Cruz Bicycles Rider Support: What driver body do I need?
Suryashankar Dasgupta founded Wise Wheeling. He has been cycling for more than 20 years, on geared and single-speed bikes, across many kinds of terrain. His guides cover bike repair, fit and gear, and each one is checked against manufacturer manuals, Park Tool and other primary sources before it’s published. Read how guides are made: https://wisewheeling.com/editorial-policy/
