Your complete guide to Shimano’s GRX gravel groupset

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Shimano GRX is a component series designed for gravel and adventure riders, bikepackers and cyclocross racers, providing a wide spread of possible builds including 10-speed, 11-speed and 12-speed setups, 1x and 2x drivetrains, mechanical and electronic shifting, wide-range or close-range gears, and dropper post integration.

In 2019, Shimano announced GRX, the "world's first dedicated gravel component group" which combines key technologies and components from road and mountain bike groupsets with some added brand new parts that should be ideal for your gravel bike. ​

Below we've tried to compile everything you need to know about the groupset giant's gravel-specific drivetrains. If you're looking for advice on Shimano's road bike components then fear not, just head over to our complete guide to Shimano road bike groupsets instead!

Firstly, GRX is divided into three different levels: 

RX800 series

• Equivalent to the Shimano Ultegra road bike groupset
• 12-speed and 11-speed 
• Mechanical and electronic (Di2) shifting 

RX600 series

• Equivalent to the Shimano 105 road bike groupset
• Mainly 11-speed and 12-speed (although there is a 10-speed RX600 chainset too)
• Mechanical shifting only

RX400 series

• Equivalent to the Shimano Tiagra road bike groupset
• 10-speed
•  Mechanical shifting only

That's all simple enough, but things are complicated by the fact that you can't get every component at every level. You can't have a complete RX600 groupset because there's no such thing as an RX600 rear derailleur. For instance, if you want an 11-speed mechanical rear derailleur you need to go for the RX800 level. In other words, you sometimes have to mix and match.

Things are further complicated by the fact that, at the time of writing, you can only get the new 12-speed GRX with mechanical shifting. We assume a Di2 version will follow, but for now GRX Di2 is 11-speed only. 

With all that said, if GRX is for you it's easiest to decide first whether you want 12-speed mechanical, 11-speed Di2, 11-speed mechanical or 10-speed mechanical. This is the way that Shimano structures everything on its website, and we've followed this in our guide to each groupset and their variants below. 

Not surprisingly given GRX's intended use, you get hydraulic disc brakes across the board. Cassette and chain options come from current road (Ultegra, 105, Tiagra) and mountain bike (XT, SLX, Deore) groupsets.

12-speed

Buy now: Shimano GRX 820 1x12 groupset for £1,239.00 at Wiggle
Buy now: Shimano GRX 820 2x12 groupset for £1,239.00 at Wiggle

12-speed GRX is the newest update to Shimano's gravel shifting range, providing more gearing options but sticking to mechanical shifting. It's available in both 1x and 2x setups and there are options under the top-end 800 series (called RX820) and the more affordable 600 variant (called RX610).  

Shimano have named the new RX820 groupsets 'Unbeatable', 'Unstoppable' and 'Undroppable' - in reality the first two are both the same new 800-series, 1x12 version of the groupset with different cassette and derailleur options, while the latter is the single 2x12 version of RX820. 

The 600-series RX610 components haven't been given a fancy name, but at this tier you essentially have new RX610 cranksets and shifters to make your groupset more affordable. 

12-speed GRX is the newest update to Shimano's gravel shifting range, providing more gearing options but sticking to mechanical shifting. 

It's available in both 1x and 2x setups and there are RX800 configurations and a more affordable RX600 variant.

The GRX 800 series chainset is available 2x with 48/31-tooth chainrings and 1x with either a 42-tooth or 40-tooth chainring, available with 170mm, 172.5mm or 175mm cranks and each retailing at £230. 

The GRX 600 series chainset is available 2x with 46/30-tooth chainrings, and 1x with a 40-tooth chainring, priced at £150. 

The 2x setups are compatible with an 11-34T or 11-36T cassette which retails for £85 and the 1x setups can be combined with a 10-45T or 10-51T cassette which are £160. 

The key difference between the GRX 800 chainsets and the GRX 600 chainsets is that GRX 800 uses Shimano's Hollowtech II hollow crank arm technology to reduce weight.

> Gravel bikes — do we actually need them?

For the 1x setups you have the option of the RX822 medium or long cage rear derailleur, equipped with the integrated Shadow RD+ chain stabiliser, which are priced at £119.99 each.

The RX820 rear derailleur for the 2x setup is also priced at £119.99 and features the same Shadow RD+ chain stabiliser. The RX820 front derailleur is priced at £54.99.

> Shimano unveils 12-speed mechanical 105 R7100 groupset to sit alongside existing Di2

12-speed GRX comes with revamped shifters and brake levers which are optimised for flared drop bars. 

Shimano offers dedicated GRX STI (combined shift and brake) levers and you can buy them separately as well as in sets. 

The 820-series shifter and disc brake set will cost you between £330 and £350, while the 610-series shifter and disc brake set costs between £260 and £280.

The complete groupset prices are:

• Shimano GRX 820 1x12 - RRP £1,349
• Shimano GRX 820 2x12 - RRP £1,349
• Shimano GRX 610 2x12 - RRP £1,064

11-speed

Shimano's GRX 11-speed is currently the only Di2 shifting gravel groupset offered by Shimano, although it is also available with mechanical shifting.  

11-speed GRX has 1x and 2x setups in both the RX810 series and RX600 series. 

> Check out the best gravel bikes 2023

For 1x 11-speed mechanical GRX the cranksets come in two variations - RX810 (40T or 42T) both with an RRP of £219.99, or RX600 (40T) which has an RRP of £129.99. 

For 2x 11-speed mechnical GRX, there are also two models available - 48-31T (RX810) for £219.99, or 46-30T (RX600) for £134.99. For both 1x and 2x setups, it is worth considering that the 810-series will give the highest gear ratios. 

Di2 11-speed GRX has 1x and 2x setups but belongs to the 810-series only meaning you have the option of a 40T or 42T crankset for 1x, and a 48-31T crankset for 2x. 

For 11-speed GRX there's one derailleur with a long cage, belonging to the RX810 groupset which offers a range of 11-42T for 1x setups and a derailleur from 2x groupsets takes a maximum 11-34t cassette. 

Mechanical and electronic GRX rear derailleurs are available and all of them use Shimano's Shadow RD+technology. 

For Di2 groupsets the RX815 rear derailleur retails at £277.99 and the RX817 rear derailleur is £309.99. For mechanical shifting, the RX810 and RX812 rear derailleurs both retail at £109.99. 

For 2x setups you can have an 11-speed GRX groupset with either a mechanical or electronic front derailleur.

Compared to regular road front derailleurs, the GRX front derailleurs have an additional 2.5mm outboard clearance to provide space for wider tyres, up to 42mm and for this reason the front mech must be used with the matching GRX chainset. 

Again, only available in the 800-series, the Di2 RX815 front derailleur retails at £219.99 and the mechanical RX810 front derailleur retails at £54.99. 

> road.cc Recommends: gravel and adventure bikes 

The 11-speed levers also offer Shimano's dedicated GRX STI technology (combined shift and brake). 

The 800-series lever is available for Di2 and mechanical groupsets retailing at £244.99 and £239.99 respectively and Shimano also offers a mechanical shift RX810 left lever that, when used with a 1x11 drivetrain, can control a dropper seatpost, costing £224.99. 

There is also a 600-series lever which retails at £189.99. 

Shimano GRX also includes 1x11-specific BL-RX810 and BL-RX600-series left side hydraulic disc brake levers with no dropper or shift internals. 

You can also buy STI levers and brake calipers in sets with one option for Di2 groupsets and two options for mechanical.

For Di2 groupsets the ST-RX815/BR-RX810 set retails at £344.99 and for mechanical 11-speed, the ST-RX810/BR-RX810 set is £339.99 and ST-RX600/BR-RX400 set is £249.99.

The complete groupset prices are:

• Shimano GRX RX815 Di2 1x11 - RRP £1,879.99
• Shimano GRX RX815 Di2 2x11 - RRP £2,199.99 
• Shimano GRX RX800/600 mechanical 1x11 - RRP £909.99
• Shimano GRX RX810 mechanical 2x11 - RRP £1,049
• Shimano GRX RX600 mechaincal 2x11 - RRP £855.99

10-speed

Shimano GRX still offers 10-speed mechanical groupset which is only available as a 2x setup, using components primarily from the cheapest GRX subgroup - RX400. 

There is no GRX 400 series chainset. Instead, there's a RX600 10-speed chainset with 46/30-tooth chainrings which retails at £109.99. 

The RX400 rear derailleur offers a range of 11-36T and costs £64.99 and the RX400 front derailleur retails at £39.99. 

> Check out 10 Shimano GRX bikes you can buy now from Canyon, Bianchi, Scott, Giant, Trek and more

As with the 12-speed and 11-speed groupsets, 10-speed levers use Shimano's dedicated GRX STI technology (combined shift and brake) and are available to buy on their own or as a set with brake calipers. 

A 400-series lever retails at £145 while the ST-RX400/BR-RX400 lever and brake caliper combo costs £239.99. 

Complete groupsets are now more difficult to find but are priced at around £600. 

For more details on Shimano groupsets, check out Shimano's website.

Explore the complete archive of reviews of groupsets on road.cc