Road bike cassette

No, an 11-speed cassette does not work properly with a 12-speed groupset, and vice versa. Cassettes and chains are specific to each number of speeds: the spacing between the links on a 12-speed chain is different from that of an 11-speed chain. Within the Shimano 12-speed road range, cassettes are compatible between 105 Di2, Ultegra Di2 and Dura-Ace Di2 on the same standard HyperGlide freehub body. Notable exception: Campagnolo uses the same cassette body for its 11-speed and 12-speed systems, allowing a 12-speed cassette to be fitted to an existing 11-speed body.

The difference is most noticeable on prolonged climbs with gradients exceeding 8%. With an 11-28 cassette and a 50-34 compact chainring, the 34x28 gear ratio allows a fit cyclist to climb gradients of 8 to 10% comfortably. With an 11-32, the 34x32 gear ratio allows you to tackle gradients of 12–15% without risking a loss of rhythm. The downside: the 11-32 cassette has larger gaps between the intermediate sprockets, which can make it difficult to maintain a steady cadence on the flat. For a cyclosportive on hilly terrain, the 11-32 remains the best compromise.

The cassette has no visible wear indicator: the condition of the chain is the guide. If you regularly replace your chain when it reaches 0.5% wear (measured using a chain wear gauge), the cassette will generally last for 2 to 3 chains. Signs that a cassette is worn and needs replacing: gear changes become imprecise even after adjusting the cable, the chain skips over certain sprockets under load, or the sprocket teeth take on a pointed, asymmetrical shape known as ‘cockscomb’. A worn cassette with a new chain causes skipping and accelerates wear on the new chain.

Yes, provided they have the same number of speeds, with a few caveats. Shimano and SRAM 11-speed cassettes share the same HyperGlide freehub body and are generally interchangeable, although gear changes may be slightly less precise between different brands. In 12-speed, the Shimano road cassette still uses the HG body and can be used with a SRAM 12-speed groupset in some cases. However, SRAM AXS 12-speed cassettes require the XDR body and are not interchangeable with a Shimano 12-speed cassette. Campagnolo remains a closed system: its cassettes can only be used with Campagnolo bodies.

Steel is the reliable and economical standard, aluminium reduces weight, and titanium maximises both. Steel cassettes (e.g. Shimano 105, SRAM Rival) weigh 250 to 300 g depending on the gear range and last the longest. Mixed aluminium/steel cassettes (e.g. Ultegra, SRAM Force) weigh around 180–220 g whilst maintaining good durability. High-end titanium or full-aluminium cassettes (Dura-Ace, SRAM Red) weigh under 160 g but wear out more quickly under intensive use. For a cyclist covering 5,000 km a year, an Ultegra or Force cassette offers the best balance of weight, durability and price.

Technically possible in some cases, but not recommended without an adapter. Shimano 12-speed MTB cassettes (such as SLX and XT) use a Micro Spline body, which is incompatible with the road bike HyperGlide body. SRAM Eagle MTB cassettes use an XD or XDR body. However, some SRAM 12-speed Eagle cassettes are compatible with a wheel fitted with an XDR body and an AXS road groupset: this is the ‘mullet’ setup (road crankset + MTB cassette) popular with gravel and bikepacking enthusiasts. It is essential to check that the road derailleur can handle the largest sprocket on the MTB cassette (often 42 to 50 teeth).

The cassette should ideally be cleaned every time the drivetrain is thoroughly cleaned, i.e. every 300 to 500 km. For routine maintenance, simply apply a degreaser between the sprockets using a brush, followed by a rinse with clean water. A thorough clean involving removal of the cassette is recommended every 1,000 km: metal particles and old grease build up between the sprockets and create an abrasive that accelerates chain wear. Don’t forget to lightly re-lubricate the cassette after cleaning, even though the chain receives the majority of the lubricant.

Not necessarily, but it is often advisable. If the cassette is worn and you fit a new chain to it, the new chain may jump off the worn sprockets and wear out prematurely itself. The golden rule: change the chain regularly (every 3,000 to 5,000 km depending on conditions) to prevent the cassette from wearing out. If you change the cassette, it is recommended that you fit a new chain at the same time so that the components can bed in together. The exception: if the cassette has covered less than 5,000 km and the sprockets show no signs of deformation, it is acceptable to keep it with a new chain.

For high-altitude mountain riding, an 11-34 cassette with a 50-34 compact crankset is the standard.The 34x34 gear ratio (1:1) allows you to maintain 60 revolutions per minute at around 7.7 km/h, which is sufficient for gradients of 12–15% such as Alpe d’Huez or the Tourmalet. With a 52-36 semi-compact crankset, an 11-32 cassette is sufficient for regular climbers. Always check that the rear derailleur has a long cage to accommodate the large sprocket: a short-cage derailleur is limited to 28 or 30 teeth, depending on the model. Shimano identifies its long-cage derailleurs with the suffix ‘GS’ in the product code.