Most of the cycling world has been looking at Shimano over the last few months, especially those who like to ride on more than just tarmac.
All of this is down to the release of a new, and very long-anticipated groupset - Shimano GRX. The Japanese company has finally done it! The gap in their gravel range, that was being dominated by its competitor SRAM with its Apex, Rival and Force, has been finally filled. And it's not only that, Shimano has definitely done their job and released parts that have been worth waiting for.
But why are there so many variations of new components? Which version of the Shimano GRX will be best suited to your gravel bike? We are going to try to make this a little bit easier for you to decide.
What does our gravel bike get in every Shimano GRX groupset?
Firstly, the derailleur has a clutch! Until now, gravel riders who didn't want to go to the SRAM side had a hard time with this one. The Shimano mountain groupsets have a different cable pull ratio, so we can’t pair a MTB derailleur with road shifters.
A gravel bike with Shimano - what options did we have in the past?
The Ultegra RX - a road derailleur with a clutch - came to the rescue in the summer 2018. Still, it wasn't what we had been waiting for - firstly, the purists were more bothered by the fact it wasn’t a uniform groupset, and secondly, the Ultegra RX had one significant problem. The cage - which only supported cassettes up to 34 teeth. For 2x11 drivetrains, this matter had already been solved and to this very day many people still combine e.g. Shimano 105 with this unique derailleur to achieve a sensible gravel drivetrain.
However, for fans of 1x11, the 11-42 cassette is an absolute minimum today, and Shimano Ultegra RX couldn’t deliver that .
The Shimano GRX groupset came to the rescue. It finally had a derailleur that was compatible with road shifters, came with a clutch, and a cage dedicated for cassettes with a maximum range of 11-42t. It’s, of course, made using Shadow technology, and it nicely retracts into the contour of the frame, making it less vulnerable to dangerous encounters with branches.
Apart from the obvious aesthetics (Shimano GRX is one of the nicer groupsets in our opinion), another thing that quickly becomes apparent is the new shifter design. The shifter itself is wider and thus ensures a more secure grip and intuitive braking. Additionally, the axle of the brake lever has been raised so that the force we need to apply to the brake is reduced. Another positive is the use of Servo Wave technology, known from MTB brakes, in the RX800 version of shifters. Thanks to this technology, braking requires even less force, and brake modulation is even more accurate. It's also important to note that the company has completely abandoned mechanical brakes - no Shimano GRX subgroup has mechanical shifters. Therefore, if, for some reason, you dreamed of a gravel bike without hydraulic brakes, you'll, unfortunately, have to look further.
Another thing Shimano bet on, in line with the current trend, was to go for wider tires. And so, in this case, we have a modified chain line - the crank is extended outwards by 2.5 mm. Due to this modification, the GRX, even with two chainrings and a front derailleur, will take typical gravel tires.
These are the general changes that Shimano has made compared to its other groupsets. Okay, but what options do we have? And how does this relate to current standards at all?
An incredibly important issue is, of course, the right gear range. The lack of low gears will make it impossible for us to ride effectively in the mountains. The lack of high ones, on the other hand, will make us look like a hamster on a wheel on the descents.
Shimano released one derailleur with a long cage, belonging to the RX800 groupset. It offers a fairly standard range of 11-42t. When it comes to cranksets we have a choice between RX800 (40t, 42t) or RX600 (40t). So, if you ride a lot on the road, it's better to take a crankset from the higher groupsets with 42 teeth, it'll give you the highest ratio of 3.82, instead of 3.63 in the case of a 40t sprocket. The smallest ratio we can achieve is 40/42 or 0.95. It'll work on 90% of gravel routes unless we're riding in the mountains loaded with big panniers.
A derailleur from 2x groupsets takes a maximum 11-34t cassette, while the cranksets come in two variations - 46-30t (RX600) and 48-31t (RX800). Again, we can see that for a higher groupset intuitively, according to the level of advancement, heavier gears are available. The RX600 version will, therefore, give us a ratio from 4.18 to 0.88 and the RX800 from 4.36 to 0.91. At the expense of the simplicity of the 1x11 system, we, therefore, get the largest range of ratios, which should work equally as well in the forest as on the road.
The cheapest GRX subgroup, RX400, has a rear derailleur that offers a range of 11-36t and a crankset, just like the RX600, 46-30t. So it gives us the lowest gears we can find in the new Shimano equipment, from 4.18 to 0.83. The expense, in this case is poorer variation and larger gaps between the gears.
Shimano GRX Hierarchy
Basically, there are 3 levels of Shimano GRX:
- RX800 equivalent to Ultegra, in a mechanical version and Di2, 2x11 or 1x11 drivetrain
- RX600 equivalent to the 105, 2x11 or 1x11 drivetrain
- RX400 equivalent to Tiagra 2x10
1x11 derailleurs work, officially, with cassettes up to 42t (they can also work, unofficially, with 44t and 46t), so most climbs won't be too scary. The only thing we can fault is the lack of no small chainrings for the 1x11, up until now, only 42t and 40t sizes have been available. Yes, they are indeed suitable for 90% of the conditions, but with a bike loaded with bikepacking bags on uphill stretches of +10%, a 38t or 36t chainring could be a bit more useful at times.
In addition to braking, the left-hand shifter can also operate an adjustable seatpost with a 1x11! This gives us a nice option to get rid of extra things from the cockpit and clean it up to the maximum. There are also additional cyclocross shifters available for mounting right next to the stem.
If you would like even more technical information, please refer to the great GRX group guide, prepared by Shimano, here.
Which version of Shimano GRX should your gravel bike have?
If you are still wondering whether it is better to have one or two chainrings, we recommend reading our article entirely devoted to this issue.
This, obviously, is the most affordable option, available only in the 2x10. If you care for the Shimano GRX, but don't care for a 1x11 drivetrain, and want to save as much as possible, this option will be enough for you. The precision and operation of the rear derailleur are still at a high level, and if you don't ride professionally, it's pretty likely that you won’t be missing this one gear at all.
The best price-to-quality ratio will be RX600, like Shimano 105, it’s a mid-range groupset, and it already has a full selection of gears - 1x11 or 2x11, that is completely suitable for all kinds of adventures. The gears run smoothly, quietly, and the derailleur can cope well even under load. The RX600 in a 1x11 version will easily get us through every bikepacking trip, even on light singletracks, where gravel bikes seem to find themselves surprisingly well.
The 2x11 version is ideal for a more endurance version of a gravel bike, and no long-distance racing is going to be too scary for it.
The Shimano GRX RX800 may be an overkill in some cases. The weight and workmanship are even better, but the improvement of the performance of the drivetrain is minimal. For the time being, we don't yet know what the issue of durability is.
We'll obviously feel the difference after switching to the Di2 version. But it's already quite an expensive game, the whole groupset costs over 900€!
To sum up, Shimano has really made an effort, and changes compared to its other groupsets are not only limited to appearance. Shimano GRX is really well thought-out equipment that will find its place in the bicycle pantheon for good. The Japanese company has very skillfully created a bridge between road and mountain bike components, and riding a gravel bike with a GRX groupset is an absolute pleasure.
On our website in addition to fixed gear and city bikes, you can also find the latest range of Loca Bikes gravel bikes. Write to us, we'll happily answer any questions that you have, and what’s more, we'll put a nice bike together for you.