Unless you’re running a triple crankset, it’s unlikely you’ll want to use a road bike cassette on a mountain bike. Dave Caudery / Immediate Media Like rear derailleurs, front derailleurs have a maximum capacity. Here it relates to the difference in size between the large chainring and the small chainring. So, say you are using 50/34T chainrings: the difference is 16 teeth. You may sometimes see brands refer to their cassettes as having a certain range in the form of a percentage. Whereas some chainsets feature a aluminium axle in a 30mm diameter, Shimano uses a steel axle with a 24mm diameter across the board. When he reviewed the Ultegra levers (above) Stu Kerton said, “The biggest difference of R8000 [current generation Shimano Ultegra] over 6800 [the previous version] is the shape of the brake lever. The curve for your index finger is more pronounced and if, like me, you like to wrap your finger around the bar when on the hoods then you'll find it very comfortable.

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. The 105 levers have been redesigned with shifting mechanisms that make the shift a bit more snappy than before, and the shape of the lever is squarer, slightly more compact and features a patterned rubber cover for extra grip on the hoods. The capacity of a Shimano 105 front derailleur, for example, is 16T so it’ll cover all of the common double chainset combinations.The idea set up would be to have either 105 in the front and Ultegra in the rear, like my bike, or go whole hog and get the DA in the rear, personally I don't see any need for DA. If you use DA 9000 cables on even a full 105 bike and did a blind test ride you would think you were riding on DA because the DA cables are better than standard Shimano cables. we need to be clear what we mean when we write 'gears': do we mean cog and chainring teeth (11-12-13 &c and 52-39 &c)? Cog & chainring combinations (52x13)? 11sp vs 10sp? Gear sequence (1st to 22nd)? Gear relationship (higher/lower; highest/lowest)? Cog number on cassette (1-11)? Gear ratios (1:1, 2.74:1)? Gear inches (30–135")? Metres development (4.56)? 'Gain'? Speed at rpm? Or the whole system (derailleurs, chain, cassette, [internal hub] chainrings)? Although it might seem straightforward, there’s a lot of engineering that goes into a bike cassette.

We're going to focus on Shimano systems in this article, as that covers the majority of bikes out there. Rear derailleur capabilities You don't get the carbon brake lever that you have on Ultegra and Dura Ace, so the levers are a bit heavier as a result. These are the mechanical levers: there's also a new hydraulic lever for use with hydraulic disc brakes, which replaces the current, slightly clunky, RS505 unit. We have those in for testing too but we'll report on them separately.In the last couple of years, Shimano has introduced 11-34 cassettes at Tiagra, 105 R7000, and Ultegra R8000 levels, so the old 105 5800 is now the only enthusiast-level groupset you're likely to find on a new bike that doesn't officially work with 11-34, and there's not much 5800 left on bikes in the shops. You can always upgrade the rear mech to R7000. Where it makes sense to spend money even on the commuter is for cables - a good set of cables can keep you shifting well much longer. Also don't skimp on brake pads (where I don't buy Shimano anyhow). These days, it is increasingly common to see higher-spec road bikes with 12-speed gearing, Shimano having joined SRAM and Campagnolo with 12-speed groupsets in 2021 with the release of its Dura-Ace Di2 R9200 groupset. Visually, it departs from the previous RD-R7000 rear derailleur, gaining a flattened body and the same 105 branding from the Di2 R7150 rear derailleur.