For example, at the lower end of the cassette, you can have as little as a one-tooth jump between the early cogs, and still have the range at the easier end. If you were running a 7- or 8-speed system, for example, in the same range, the jumps would be bigger. SRAM XDR road cassettes are 1.85mm wider than SRAM XD MTB cassettes. With a spacer, you can run an XD cassette on a road wheel with an XDR body, but you can’t use an XDR cassette on an XD freehub. Mountain bike versus road cassettes On the mountain bike side, Shimano uses its Microspline freehub standard for its 12-speed Deore, SLX, XT and XTR groupsets.

For mountain bikes, 12-speed cassettes are largely the default for higher-spec groupsets, paired with a single-ring chainset. It’s important to note that this figure is only indicative of the range of gears you have on your cassette, and is not the same as working out how far you will travel with your chosen gear ratio. You may sometimes see brands refer to their cassettes as having a certain range in the form of a percentage. SRAM’s eTap AXS XPLR groupsets are designed specifically for gravel riding. SRAM XPLR cassettes have a range of 10-44 and require their own compatible rear derailleur. It is also possible to mix and match drop bar shifters with mountain bike Eagle eTap AXS components if you want an especially wide-range 1x build. SRAM dubs this a ‘mullet’ setup.The cage of a rear derailleur is designed for a certain range of gears. For example, Shimano’s outgoing Dura-Ace R9100-SS rear derailleur is designed for use up to an 11-30 cassette. Gravel bikes are best viewed as a crossover between a road and mountain bike. As such, it’s normal to see them specced with either a road or mountain bike cassette.

Now that 12-speed road bike groupsets exist, cassettes can have a larger range and the jumps between each gear can be relatively small. It would have been uncommon to find a cassette as large as SRAM’s Eagle 10-50 a few years ago. Alex Evans If you are specifically using a Shimano HG freehub, you need to consider how wide the cassette you are buying is. Road wheels have slightly wider freehubs than MTB ones – by 1.85mm – and 11-speed Shimano HG road cassettes are slightly wider than 8- or 9-speed ones, again by 1.85mm. Where an 11-28 would have been considered an ‘easy’ training cassette a few short years ago, the smallest cassette available for a Shimano Dura-Ace R9200 is an 11-28. That might not sound like much but, when you consider pro riders would typically ride on 11-23 or 11-25 cassettes, it’s a sizeable difference. You will need a long-cage derailleur if you want to use an 11-34t cassette on a road bike. Simon Bromley / Immediate MediaWell, the smallest cog is a 10-tooth, and the largest cog is 52-tooth, which is 520 per cent larger than the 10-tooth cog, thus giving a 520 per cent range.

However, as groupset manufacturers have jumped onto the gravel bandwagon, there are now gravel-specific gearing options available on the market. For example, SRAM boasts a 520 per cent range with its 10-52t cassettes. How has SRAM arrived at this figure, and how do you work out your gear range percentage? Although it might seem straightforward, there’s a lot of engineering that goes into a bike cassette. Finance is subject to application, financial circumstances and borrowing history. Performance Cycling Limited FRN: 720557 trading as Tredz are authorised and regulated by the Financial Conduct Authority. We are a credit broker not a lender – credit is subject to status and affordability and is provided by Mitsubishi HC Capital UK PLC. Terms & Conditions Apply. If you wanted to use an 11-34 cassette, as well as buying the relevant cassette, you would need to buy a compatible rear derailleur. In this example, it would be an Ultegra R8050-GS or 105 R7000-GS rear derailleur. The GS denotes that these are ‘medium cage’ derailleurs. The same rule applies to Shimano Di2 derailleurs.Shimano, for example, uses a system it calls Hyperglide, which is engineered to provide smooth shifting. Its latest cassettes have a newer system called Hyperglide+, which Shimano says reduces shifting time by up to a third relative to Hyperglide, and improves shifting performance under power, up and down the cassette. You need to ensure you’re using a compatible rear derailleur if you’re using the 10-52 option, because the previous-generation Eagle mechanical rear derailleur’s cage is slightly too short.