More sprockets, more options: Shimano presents the new GRX for gravel bikes

Japanese component manufacturer Shimano has presented the second generation of the GRX gravel bike drivetrain to the public. Like the current road bike drivetrains, the new drivetrain now comes with twelve instead of eleven sprockets on the rear wheel and can be combined with either one or two chainrings. The new GRX is available in two quality levels: in addition to the GRX820, there is also a cheaper GRX610. The GRX400, previously the cheapest version, has been discontinued. The components are almost fully interchangeable and form a kind of modular system. Compared to the first generation, this is now much clearer, which may not please everyone: An electronic Di2 variant, which was still offered in parallel for the Elffach groupThere will not be any for the twelve-speed drive for the time being.

Shimano GRX: New gear ratios for single drivetrains

Drivetrains with a single chainring are becoming increasingly popular on gravel bikes. In terms of gear ratios, Shimano has therefore expanded the range of single configurations in particular. The GRX uses cassettes from the XT mountain bike groupset; the range includes a sporty 10-45 and a wider 10-51 gradation. However, due to the ten-tooth starting sprocket, these are only compatible with wheels with a Microspline freehub; they do not fit the classic HG freehub. Different derailleur cages are required for the two cassettes, the larger one requiring a longer one. The cage can be easily changed on the new rear derailleurs so that the entire rear derailleur does not have to be replaced when changing the gear ratio. A 40 mm chainring is the golden mean on the crank, with a 42 mm chainring also available as an alternative for the GRX820 and an optional 38 mm chainring for the GRX610.

Shimano GRX: 2x12 for the highest demands

Fans of even gear steps with maximum gear range should be happy with the double setup of the new GRX. The cranks offer a 48/31 (GRX820) or 46/30 (GRX610) gradation, while the cassettes are an 11-34 and an 11-36 from the road bike portfolio. They also fit eleven-speed freewheels in the Shimano HG standard, so they are also compatible with older wheels. The chain line is offset by two millimetres from the road bike components, meaning that the front derailleur officially allows tyres up to 42 millimetres wide.

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New lever ergonomics

The shift brake levers of the GRX have also been revised for the second generation. The levers of the GRX820 have been adapted for mounting on the typical, laterally flared gravel handlebars. To this end, the mounting clamp has been modified so that the grip bodies on these handlebars provide a horizontal contact surface for the hands. The levers of the cheaper GRX610 are excluded from this change. For the configurations without front derailleur, there are left brake levers without shifting mechanism; alternatively, a special lever is available that can operate a mechanically controlled, retractable seat post.

Affordable and functional: GRX610

While the GRX820 also appeals to demanding off-road riders with its state-of-the-art technology, the "little sister" GRX610 is aimed at price-conscious customers and beginners. Bikes in the popular price range of around €2000 will primarily be equipped with this version. It differs visually from the more expensive GRX820 in its finish, which is predominantly matt instead of highly polished. GRX610 riders will also have to do without some technical refinements: The GRX610 will not have ServoWave technology - a non-linear brake force transmission of the levers that reduces hand force during very heavy braking. The levers are also not adapted to modern flare handlebars like the 820s. The crank is not hollow-forged, but a two-piece design, and is therefore significantly heavier than the Hollowtech II crank of the GRX820.

Matching gravel wheels with carbon rims

With the RX880, Shimano is presenting new wheels for off-road use to match the GRX. The 32 millimetre flat carbon rims are tubeless-compatible, and with a 25 millimetre rim width they are suitable for tyre widths from 32 to 50 millimetres. A special feature is that the freehub body can be easily changed - the wheels are equally suitable for single and double setups, and the gear ratios can also be easily converted.

The new GRX is now available in all configurations, and the first production bikes equipped with it for the 2024 model year are expected to be presented soon. Gravel bikes with the GRX610 are likely to cost around € 2000; with the GRX820 around € 3000.