You have found a used or clearance cassette at an attractive price, but one question always comes up before placing your order: will it be compatible with my bike? Unlike buying a complete bike where everything is already matched, replacing only the cassette requires checking three independent components: the freehub body, the rear derailleur, and the chain. An incompatibility with just one of these three elements can make the drivetrain unusable.
This guide explains, step by step, how to check the compatibility of your future road bike cassette before purchasing, helping you avoid unpleasant surprises when your parcel arrives.
1. Why compatibility is the main issue
With a new bike, the bike shop or manufacturer has already matched the cassette, rear derailleur, chain, and freehub body together: you never need to ask the question. When buying used or clearance components, it is up to you to recreate this compatibility, without an automatic system or expert validation to check it for you.
Three checks are essential before placing any order:
- Does your wheel's freehub body accept the cassette spline pattern?
- Can your rear derailleur handle the number of speeds and the largest sprocket of the cassette?
- Is your chain suitable for the number of speeds of the cassette?
The following three sections explain each of these points in detail.
2. Cassette / freehub body compatibility
The freehub body is the splined part attached to the rear hub onto which the cassette is mounted. Its shape must exactly match the cassette standard: a Shimano cassette cannot be installed on a SRAM XDR freehub body, and vice versa.
| Standard | Brands concerned | Typical use | Number of speeds |
|---|---|---|---|
| HG (Hyperglide) | Shimano, SRAM road (except 12-speed AXS), multi-brand cassettes | The most common standard, including on used wheels | 8 to 11 speeds |
| XD / XDR | SRAM (Force AXS, Red AXS, Rival AXS) | 12-speed cassettes with a 10-tooth smallest sprocket | 12 speeds |
| N3W | Campagnolo (Super Record S, Chorus 13-speed) | Recent wireless Campagnolo groupsets | 13 speeds |
| Micro Spline | Shimano MTB (XTR, XT, GRX 12-speed) | Mainly gravel/MTB use, check carefully for mixed setups | 12 speeds |
✅ = the most common standard on road bike wheels currently in circulation · 🔴 = specific standard, must be checked carefully before purchase.
3. How to identify your wheel's freehub body
Method 1 — The wheel or hub reference number
The most reliable method is to find the exact reference of your wheel (usually printed on the hub flange or on the rim sticker) and check the manufacturer's technical specifications. Wheels supplied with a 12-speed SRAM AXS groupset are almost always fitted with an XDR freehub body; older wheels or wheels supplied with a Shimano groupset generally use the HG standard.
Method 2 — Inspecting the splines
Visually, an HG freehub body has fine and evenly spaced splines around the entire circumference. An XD/XDR freehub body can be identified by a wider and asymmetrical spline near the base, designed to accommodate a 10-tooth smallest sprocket directly machined into the body on some SRAM cassettes.
Method 3 — Testing with the cassette in hand
If you already have the cassette, it simply will not fit onto an incompatible freehub body: the splines will not match. Never force the cassette into place, as this could damage the freehub body or the cassette.
Tip: Before ordering a used cassette, get into the habit of checking the reference of your rear wheel. This information alone eliminates most compatibility mistakes.
4. Cassette / rear derailleur compatibility
Rear derailleur capacity (total capacity)
Each rear derailleur is designed to handle a maximum difference between the smallest and largest sprockets, combined with the difference between your chainrings. This figure, known as total capacity, is calculated as follows:
Total capacity = (large chainring − small chainring) + (largest sprocket − smallest sprocket)
Example: a 50/34 crankset combined with an 11-32 cassette gives (50−34) + (32−11) = 16 + 21 = 37. If your rear derailleur has a maximum capacity of 33, this combination will not work correctly.
Number of speeds: can an 11-speed derailleur accept a 12-speed cassette ?
Generally speaking, no: the spacing between sprockets differs depending on the number of speeds, and the derailleur indexing is designed for a specific number of speeds. A 12-speed cassette requires a derailleur, chain, and often shifters designed for 12 speeds. To explore this topic further, see our guide on 11 and 12-speed cassettes (article coming soon in this content section).
Can different brands be mixed ?
Shimano and SRAM HG-standard cassettes often share the same sprocket spacing for a given number of speeds, which means occasional mixing can be possible in many situations. Campagnolo, however, has historically used its own proprietary sprocket spacing, even when the number of speeds is identical. Mixing a Campagnolo cassette with a derailleur or chain from another brand is strongly discouraged without precise confirmation of the component references. For a detailed brand-by-brand overview, see our Shimano, SRAM and Campagnolo comparison (article coming soon in this content section).
5. Cassette / chain compatibility
The internal width of a chain decreases as the number of speeds increases, allowing it to fit between increasingly closer-spaced sprockets. A chain that is too wide will not sit correctly on a modern high-speed cassette; a chain that is too narrow on an older cassette will perform poorly and wear prematurely.
| Number of speeds | Chain width (approximate) | Remark |
|---|---|---|
| 8-9 speeds | ≈ 6.6 to 7.3 mm | Good cross-brand tolerance |
| 10 speeds | ≈ 5.9 to 6.2 mm | Check manufacturer compatibility |
| 11 speeds | ≈ 5.5 to 5.65 mm | Campagnolo 11-speed generally requires its own chain |
| 12 speeds | ≈ 5.25 to 5.3 mm | SRAM Flattop = proprietary design, not interchangeable |
These values are approximate: always refer to the cassette manufacturer's technical specifications before choosing your chain.
Another point to watch: a worn (stretched) chain gradually damages the tooth profile of a cassette, even a new one. This is known as cross-wear. Installing a new cassette on an already worn chain greatly reduces its lifespan. To learn more about this topic, our article How to replace a road bike cassette explains how to replace the cassette and chain together.
6. Compatibility summary table by brand and generation
| Brand / Range | Speeds | Freehub body | Compatible chain |
|---|---|---|---|
| Shimano 105 / Ultegra / Dura-Ace | 10 to 12-speed | HG (10-11-speed) / Micro Spline or HG depending on generation (12-speed) | Shimano chain with the same number of speeds |
| SRAM Rival / Force / Red (mechanical) | 10 to 11-speed | HG | SRAM chain or compatible HG chain with the same number of speeds |
| SRAM Force AXS / Red AXS | 12-speed | XDR | SRAM Flattop chain (proprietary) |
| Campagnolo Chorus / Record / Super Record | 11 to 13-speed | HG (11-speed) / N3W (13-speed Super Record S) | Recommended Campagnolo chain with the same number of speeds |
Key point: The three components (freehub body, rear derailleur, and chain) must be checked independently. A cassette may be mechanically compatible with your freehub body but completely unsuitable for your derailleur if the largest sprocket exceeds its maximum capacity.
7. Common mistakes to avoid when buying a used cassette
Watch out for these common mistakes:
- Failing to check the freehub body before ordering
- Confusing the derailleur's number of speeds with the cassette's number of speeds
- Ignoring rear derailleur capacity when using an unusual large sprocket (e.g. 11-34)
- Reusing a worn chain with a new cassette
- Assuming that a Campagnolo cassette will work with a Shimano or SRAM groupset without checking compatibility
8. FAQ — Road bike cassette compatibility
Road bike cassette guides — learn more
- Road bike cassette — complete category
- How to choose your road bike cassette?
- How to replace your road bike cassette?
- Which cassette should you choose for mountain road cycling?
- Shimano, SRAM and Campagnolo comparison (coming soon)
- HG, XDR and N3W freehub bodies (coming soon)
- 11 and 12-speed cassettes (coming soon)