With the GRX RX800, Shimano offer a groupset specifically designed to meet the demands of gravel riders. How did the 2×11 drivetrain fare in our long-term test? Did the GRX throw in the towel after almost 2,000 km on hard gravel roads? Here are all the details and info as well as a comprehensive test of the entire groupset.
The Japanese components colossus, which equips most of the bikes in the pro peloton, recognised that the gravel segment was in urgent need of a dedicated range of components. With the GRX lineup, Shimano want to provide the optimal basis for endless and carefree gravel fun, both in the shifting and braking department. And that at any time, in any place and without complaining. Before taking a closer look at the technical aspects and performance of the groupset, we want to give you an overview of the GRX product range.
What is the GRX groupset anyway?
The Shimano GRX is a gravel-specific groupset, available in three versions: the expensive RX800 version, which compares to an Ultegra road groupset, the RX600 model (105) and the more affordable RX400 (Shimano Tiagra). To give you a better overview, we’ve summarized all available versions of the GRX lineup in the following table:
|GRX-Version||Gears||Mechanical / electronically||Gear range|
*in the 1×11 version also possible with control of a hydraulic dropper post
Does the World really need a gravel-specific groupset?
The answer is: YES, it does! Sure, there’s a huge number of suitable groupsets for bikes with drop bars. Nasty climbs that are exhausting even in the lowest gear on tarmac, would be impossible to conquer on gravel. The solution to this problem? A wide gear range. Unfortunately, using a cassette with an overall lower ratio isn’t enough, because gravel bikes also want to be pushed hard on flat roads – and they love speed!
If you spend most of your time riding offroad on Alpine terrain, you’ll appreciate the versatility of a 1x setup. By getting rid of the front derailleur you’ll save weight, and a wide-range cassette will compensate for the missing chainring. However, gravel is much more than just riding Alpine passes on gravel roads. Our test bike, the Mason Bokeh GRX (click for review) had to combine several disciplines, from bikepacking trips, through mixed gravel expeditions (50% road, 50% gravel) to the daily commute to work – here a finely-graded 2×11 drivetrain with a suitable gear range is still the best choice. In all of the above scenarios, a standard road-bike groupset doesn’t cut the mustard. So there you go: there’s no gravel riding without a gravel-specific drivetrain!
2x drivetrains ain’t dead! If you’re after uncompromised versatility, they’re definitely an exciting alternative.
Shimano GRX RX800 long-term review
Quite a few of the gravel bikes we’ve tested over the past few months came with one of three versions of the Shimano GRX groupset. How did the mechanical RX800 groupset fare in this tough 2,000 km long term test? One thing’s for sure: we didn’t go easy on the bike! Test rider Ben took the Mason Bokeh and the GRX groupset through the wringer, regardless of the filthy autumn weather.
Shimano GRX ST-RX810 shift levers
Visually, the ST-RX810 shift levers, which combine mechanical shifting with hydraulic braking, are quite a handful – especially compared to the ST-RX815 levers of the electronic GRX Di2 groupset. Aesthetically, they’re definitely a matter of taste! If you have big hands or ride with gloves in winter, the big levers are practical because they allow for many grip positions – even spreading your hands into the hoods is not a problem.
Downhill, the ST-RX810 levers inspire confidence and offer outstanding grip thanks to the anti-slip profile of the hoods. However, on epic all-day rides with 10+ hours of riding, this can cause unpleasant pressure points on the hands. You can even ride downhill on the hoods and still have sufficient grip and braking power. By changing the pivot point of the brake lever, Shimano improved its functionality drastically. As a result, the revised lever allows you to keep your hands safely on the hoods and generate sufficient braking power, even on steep and scary descents, where you wouldn’t want to reach for the drops – pretty confidence-inspiring. Generally speaking, we’d always recommend riding in the drops on scary descents and in tricky situations, because this gives you more control over the bike – we definitely recommend it!
Apart from the bulky look of the levers, which can really clash with the petite silhouette of a small gravel bike, we weren’t impressed with the coating of the levers. It gets scratched far too easily and causes the ST-RX810 shifters to look old and worn after a short period of time. And while some of you might be thinking “but every scar tells a story”, it doesn’t look great – and shouldn’t happen anyway! That being said, the coating actually does its job and provides good grip even when riding in wet conditions without gloves.
Shimano GRX BR-RX810 brakes
The brakes are attached to our test bike with a flat mount at the front and direct mount at the rear and paired with 160 mm and 140 mm rotors (f/r). In terms of braking power, Shimano’s GRX-BR-RX810 brake is hard to beat. It delivers a firm bite and combines it with a very intuitive modulation. Braking power is delivered intuitively, which makes for a very beginner-friendly feel.
For our experienced test rider, who rides mainly on undulating terrain and in the low mountain ranges of southern Germany, the 140 mm rear-rotor was just about okay. However, with the bike loaded with heavy bikepacking gear, where you have to brake constantly, the rear-brake reaches its limits on long, steep descents. In order to have more reserves, we recommend a bigger and more capable 160 mm rotor. While the weight difference between a 160 mm and 140 mm rotor is negligible, the added safety benefit and bigger margin of big discs are significant. If your fork is approved for larger rotors and you spend most of your time on hefty Alpine descents, then a 180 mm XT or SLX rotor may be an even better option– specific GRX rotors are not available.
The Shimano RD-RX810 rear-derailleur, the FD-RX810-F front-derailleur and the CS-HG800-11 cassette
The gradation of the mounted 11-34T cassette is awesome and perfectly suited for our daily 40 km commute with 450 m elevation gain! It’s also a clever choice for the most diverse gravel outings, from epic rides in low mountain ranges to fast-paced afterwork laps on undulated terrain, and includes the right sprocket for every situation. However, if you’re bikepacking in the Alps you might need a slightly easier gear.
Throughout the six months and almost 2,000 km of this test, Ben had to make just one small adjustment: increase the tension of the shift-cable by half a turn. And nothing else! How cool is that? Very cool considering that the bike has been through dusty trails, muddy singletracks, tall grass and even the odd river. The robustness and reliability of the Shimano GRX-RX800 groupset are next level. The advantage over the GRX Di2 model, which has been another trusted companion on so many occasions, is that the GRX-RX800 is easier to repair when you’re left to your own devices in the middle of nowhere. If you break the battery or rip the cable of the Di2 groupset it’s game over. With the mechanical version, a spare cable can be replaced within minutes and save the day – or even the week!
The shifting performance is outstanding and impressed us with clearly defined, crispy shifts throughout the entire testing period. The levers provide immediate and consistent feedback, which means you always know whether and how many gears you’ve just shifted. At the rear, you can always shift up one gear at a time to a heavier gear and down three gears with one shift – pretty sensible for a gravel bike! After six months, the shifter runs as smooth as on its first day and makes for easy shifts even after a long day in the saddle without putting strain on your fingers.
The clutch mechanism of the rear-derailleur effectively prevents the chain from slapping on the chainstay and thus ensures a smooth and quiet ride on bumpy roads and rough trails. While Shimano still had a few issues with the Ultegra RX rear-derailleur, the revised clutch mechanism of the GRX works flawless. Remarkable: even a nasty crash that caused the bike to slide down the road on its drive-side for several meters (please don’t mention this to Mason Cycles) left the rear-derailleur unscathed. Of course, the rear-derailleur was masterfully bent into its original position on site (and of course readjusted at home;)) and still works as if nothing had happened.
The Shimano GRX FC-RX810-2 crank
Throughout the testing period, the Shimano GRX 2x crank delivered its job very discreetly. And while it’s definitely not the stiffest crank out there, it’s a great match for gravel bikes. Super stiff road cranks like the Shimano DURA-ACE make you aware of the tiniest micro-vibrations, and in this regard the GRX gravel crank is a lot more comfortable. On the other hand, it’s still stiff enough for the occasional sprint – with Ben’s 1,680 W peak sprint power, it just gave us a tired little smile – like everyone else, after all.
The Shimano SM-BBR60 bottom bracket and CN-HG701-11 chain
The 11- speed chain and bottom bracket of our test bike don’t bear a GRX logo and are not gravel-specific either. Even after almost 2,000 km, the bearings run smooth, which is not something to be taken for granted given the massive beating the bike took over the past few months! The chain is now ready for retirement – actually, you should check the chain wear with a chain tool or ruler after about 1,500 km. When replacing bearings, chains and brake pads, we always recommend using original parts for maximum service life.
Shimano GRX RX800 gravel groupset – our conclusions
We’re thrilled! Shimano’s gravel-specific groupset runs so smooth and is so reliable that you forget about it. While working discreetly in the background, it does exactly what it’s told to do, and does it extremely well! The robust construction and reliable operation of the GRX RX-800 are living proof of Shimano’s outstanding workmanship. If you don’t mind the bulky look of the massive hoods, the GRX is a reliable companion for endless gravel adventures!
- Crisp and defined shifting
- Outstanding braking power and good modulation
- Sensible gear range for gravel bikes
- Robust and reliable even after 2,000 km
- Bulky-looking hoods
- the coating on the levers is very prone to scratching
Test duration: 6 months
Price: At the time of the test the street price in Germany was € 865.00
Manufacturer’s website: bike.shimano.com
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Words & Photos: Philipp Schwab, Benjamin Topf