Colin reviews the Shimano GRX RX820

Back in 2019, Shimano announced GRX, the first gravel-specific groupset. Following the clutched Ultegra RX rear mech launched in 2018, Shimano borrowed bits and pieces from its road and MTB components to create a system designed to cope with mixed terrain riding.

Five years on, Shimano has given GRX an overhaul, unveiling three flavours of new 12-speed GRX RX820 components. As part of the official launch, I was invited to Bend, Oregon, to spend some time on the new GRX and have a groupset headed to our Gold Coast HQ for further testing.

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What’s New With Shimano GRX?

GRX 12-speed is divided up into three distinct groupsets:

• Unbeatable: 1×12 with a 10-45T cassette
• Unstoppable 1×12 with a 10-51T cassette
• Undroppable 2×12 with 11-34T or 11-36T cassettes

Ahead of the launch, we had expected to see both the mechanical and Di2 groupsets breaking cover, however for the time being, GXR 12-speed will be limited to mechanical. The official line from Shimano is that Di2 is coming, but that’s all it would tell us.

According to Shimano North America Road and Gravel Product Manager David Lawrence, the reasoning behind that is 75% of the gravel market is mechanical, so they’re aiming to satisfy the bulk of the market before updating the HALO gear.

A big point that Shimano stressed during the launch is that it aims to keep gravel accessible for all kinds of riders, whether it be folks looking to sign up to Unbound or SEVEN or those simply looking to get outside and do some exercise. The shockwave from gravel has well and truly overtaken the North American market in the last few years, and it’s still growing in Australia. But this aim to have something for every type of rider is part in parcel to why they’re offering both 1x and 2x versions of the new groupset.

In this same vein, Shimano is also trickling 12-speed down to the RX610 level groups however, cheaper components are limited to shifters and cranks.

With a tighter gear range and a 10-45T cassette, the Unbeatable group is pitched at gravel racers. The 51t dinner plate on the back of the Unstoppable group leaves slightly bigger jumps between cogs, and this set-up is pitched towards the folks after big adventures way out in rugged and varied terrain. The third Undroppable offers closer gear steps still for those who still prefer 2x on a drop bar platform.

The gear levers have had some tweaks to the ergonomics to more equally spread the pressure across the heel of your hand. Shimano says it has changed the angle of the band clamp to match 16° flared drop bars and create a flatter surface across the hoods. This change wasn’t immediately noticeable, which arguably means it’s achieved its goal.

The brakes have also been brought in line with the two-piston flat-mount stoppers rolled out across the road groupsets earlier in the year. The pad clearance has been increased by 10%, and the bleed port has been moved to the outside of the calliper body for easier access.

Seemingly under the radar, earlier this year Shimano also revamped its centerlock rotors and made a point to guide our attention to them. These aren’t just for GRX, and CL 800 and CL 900 rotors will be available in sizes from 140mm all the way up to 203mm. Shimano claims to have further improved heat management with its Ice Technologies Freeza construction. This is paired with a more robust arm structure that’s said to resist heat deformation during hard braking better.

Shimano GRX RX820 Pricing

Shimano’s GRX sits roughly in line with its second-tier groupsets, combining XT and Ultegra. With the lack of batteries and wireless communication protocols, the cost of these parts has a refreshing lack of commas in the RRP. Here’s a breakdown of how many dollarydoos a GRX 12-speed upgrade will cost.

• RX820 (2x) /RX822 Rear (1x) Derailleur ($189.00AUD)
• RX820 Front Derailleur ($93.00)
• RX8201 (1x)/RX8202 (2x) Crankset ($370)
• RX8202 Shifter RH / ($603.00 AUD) / LH ($602.00 AUD) / RX8203 LH with dropper ($566.oo AUD)
• M8100 Cassette 10-45T / 10-51T ($240.AUD)
• M8100 Chain ($75.00 AUD)

1 | KISS — Keep It Simple Shimano, reducing SKUs for bike shops

In among the three groups, the levers, brake callipers, and derailleurs have all been redesigned, however Shimano is leveraging a similar ethos to its CUES groupset in an effort to simplify its range and cut down the number of SKUs that bike shops need to stay on top of. With that, the RX820 crankset remains unchanged from the 11-speed to the 12-speed groups.

So if you have 11-speed GRX on your bike and want to add a cog at the back, you’ll just need a set of 12-speed compatible chainrings, and you’re off to the races.

The same goes for the cassette and chains. The 10-51T and 10-45T cassettes are literally XT cassettes — they even have the XT graphic on the back — and the 2x clusters are simply the Ultegra and 105 cassettes. Each groupset will come spec-ed with an M8100 chain which is the XT/Ultegra level 12-speed chain.

2 | Shimano embraces the mullet

Up until now, Shimano GRX was simply outgunned by SRAM on gearing. SRAM has had 12 cogs at the back for quite some time, and you could run an Eagle derailleur and a 10-52T cassette on your gravel bike with just about any level of the drop bar shifters. That meant 2x road gearing to 1x MTB ratios, and everything in between was available for AXS and mechanical groupsets.

Shimano’s 1×11 GRX was officially limited to a 42t cog, while 2x could only take a 34T. Shimano is typically pretty conservative with its max recommended specs, and you could get away with slightly larger gearing — I’ve personally used a 40T cassette on a GRX 2x setup — but even still, SRAM had an extra cog and up to 10 extra teeth.

Now Shimano has closed the gap.

To achieve this, Shimano has employed its existing cassettes and chains, meaning GRX can leverage some of the key tech found across the brand’s other groupsets — namely Hyperglide+. You’ll find this across the gearing for the GRX range except for the 11-36T, as this is the 105 level road cassette.

The test bike I was riding was a Specialized Diverge STR — which was an interesting enough experience to begin with — with a 10-51T cassette. As I mentioned before, this is literally an XT cassette, and throughout my time on the new GRX, I made a concerted effort to break every shifting rule known to man to try and unseat the chain and make it skip, but to no avail.

To be honest, this isn’t a big surprise, as Shimano’s mechanical mountain bike shifting is exceptionally crisp, even on the lower-end groupsets, thanks to the ramping carved into the sprockets on the cassette and the architecture of the chain.

With 40 and 42T aluminium chainrings and a 38T steel RX610 level ring available from Shimano, the gear range more or less matches what a 2x setup delivers, and it opens up a fair bit of terrain — especially around Flow’s SEQ HQ — where previously a hardtail would have been better suited. Not because of the technicality of the riding but simply for access to a lower gear to keep spinning rather than grinding.

While Shimano is only offering the three chainring sizes for now, several third-party outfits, like Wolf Tooth Components, offer 110 BCD rings ranging from 36T to 46T. We expect with this launch there will be even more options available with a tooth profile to suit Shimano’s 12-speed chain. At the same time, a few more options direct from Shimano wouldn’t go astray.

All of that is to say, when it comes to gear range, Shimano is no longer off the back.

3 | Mix and Matchable — The derailleur cages are interchangeable

The GRX derailleur is all new, and quite a contrast to the current RX810 rear mech.

For the 1x system to accommodate the 10-45T and 10-51T cassettes, GRX actually uses two derailleurs with different part numbers. Both are based around the Shadow+ design with an adjustable clutch — or chain stabiliser as Shimano prefers it to be called — the parallelogram, and everything else are identical, with the only differences being a GS (medium) or SGS (long) derailleur cage.

This has to do with the max gearing, with the GS cage only capable of spinning a 45T cog, while the SGS can take the 51T dinner plate. Shimano has built-in the ability to swap the cages out, and according to Shimano North America Brand Manager Nick Legan, it’s not an overly complex process.

With that said, he also tells us that the 1x derailleurs are not compatible with a 2x system, because there isn’t enough chain wrap.

However, since the launch Shimano Australia has confirmed it won’t be carrying the GS and SGS cages as individual parts.

4 | Micro Spline freehub standard comes to gravel

Alongside the GRX launch, the Japanese outfit is also putting out a set of Shimano carbon gravel wheels. Legan stressed to us that these are Shimano non-series wheels, not GRX.

Even still, they feature a 32mm deep carbon rim with a 25mm internal width and a hooked tyre bead. Priced at $2,199.00 AUD, Shimano says they’re ideal for tyres between 32mm and 50mm, and are claimed to weigh 1,394g with the Microspline hub body.

This is to accommodate the 10T smallest cog on the 1x MTB cassettes, however this hub is also designed to work with Shimano’s HGL2 freehub body. Not to be confused with the HG hub body we all know and love, HGL2 is only compatible with 12-speed cassettes with an 11T cog. Typically you’ll find HGL2 freehubs stem from Shimano’s road groupsets, however they’re also found on the 2x GRX. This swapability is a first for Shimano branded wheels, or hubs rather.

The hub itself uses Shimano’s ratchet ring-based Direct Engagement system. Shimano wasn’t able to confirm exactly how many degrees of engagement it offered. Still, it wasn’t obscenely loud, even with 18 of them coasting together in a group, and it didn’t have a noticeable dead stroke between the ratchet teeth connecting you get with a cheap low engagement hub.

As with groupsets, wheels take a long time to properly evaluate, but for first impressions, they offered precise handling without rattling the fillings out of your teeth and spread the 45mm Schwalbe G-One Ultrabite rubber into a usable shape allowing you to generate practical grip — even on singletrack.

5 | Can we learn anything from GRX about the next generation of MTB components?

In short, not really. GRX was the last of the Shimano family of performance groupsets to offer 12-speed gearing and has borrowed quite a bit from the current range of MTB components.

In fact, Lawrence confirmed that the new RX822 derailleur was actually built around the design of the current XT rear derailleur.

“It’s based off an XT foundation, and the biggest change is in the architecture for the cable. But other than that, they are very similar,” he says.

This was necessary because the XT rear mech doesn’t have a barrel adjuster.

While GRX still opts for a traditional derailleur hanger, instead of a direct mount solution like SRAM’s Transmission, we wouldn’t necessarily rule out the next generation of MTB rear mechs going the same direction. Very few gravel bikes utilise a UDH, so it wouldn’t make a whole lot of sense in this category — yet. However, given that SRAM convinced just about every mountain bike brand to adopt this standard, and a Shimano patent from mid-2022 Shimano shows a “coaxially” mounted rear mech, it may still be on the cards.

Given the amount of time in the presentation devoted to inclusion, making things accessible and targeting the bulk of the market, if I had to speculate, I would expect we’ll see more mechanical shifting in Shimano’s next generation of MTB groupsets. That said, the internet has also revealed a Shimano patent for a wireless electronic derailleur, so who knows!

But, following the launch of CUES, the road groupsets and now GRX, MTB has to be the next cab off the rank for a remodel.

Flow’s early verdict

Having only spent a few hours riding a groupset on unfamiliar terrain and on a new bike, it’s hard to make definitive conclusions. However, from this first impression, the new GRX is not earth-shatteringly different to its predecessor — like how Transmission completely reimagined SRAM’s MTB groupsets — instead, it refines what the platform has to offer and closes the gap to its competitors.

Shimano is typically pretty conservative when it comes to new tech — though there are exceptions to this rule — and up to this point, GRX has been a little bit off the back of SRAM and even Campagnolo in some respects.

While this launch is limited to mechanical shifting, it’s clear Shimano has been quietly listening and watching what the market says it wants. Most folks are buying gravel bikes as second or third bikes, and aren’t looking to spend five figures. Many loud voices have also been decrying the slow death of analogue shifting across each category. GRX mechanical provides the gear range, a distinct lack of batteries and should hit the pricing on complete bikes.

And in this short period of ride time, it effectively stymied all of my efforts to break it. Shifting under power, dropping a load of gears while ratcheting, intentionally fishing for vague shifting — essentially, I did everything I could to snap the chain or suck the rear mech into the rear wheel short of pinging it off a rock.

Even caked in Bend’s infamous moondust GRX 12-speed mechanical prevailed.

Shifting was crisp, sharp and quiet despite my best efforts.

I can’t say I immediately noticed much in the way of the ergonomic updates, and I had the same sort of tiredness in my hands that is expected after a few hours of riding on the previous RX810 levers. However, I did feel like the lever throw had been shortened. When I asked the Shimano folks about this, they weren’t sure, and this wasn’t a specific engineering outcome but speculated the extra tooth on the internal ratchet may have had this effect. We’ll measure it when have both sitting next to one another.

There are a few bits of this latest release that may seem a bit piecemeal on the surface — using an XT cassette and not even branding it GRX and not updating the crank. However, I think this is awesome and plays into the ethos of simplicity that Shimano aims to achieve with CUES.

By and large, at this stage in component innovation, cranks are largely cranks, and cassettes are largely cassettes if you’re making apples-to-apples comparisons, i.e. crank length, material, cassette range, price point etc. Given how difficult it has been to come by certain components over the last few years, simplifying things and making more pieces of bikes cross-compatible is a good thing.

No, this doesn’t often lead to sexy new bits you can bolt on your bike, however simplicity and reliability rule the day — especially when you’re out in the middle of nowhere. It seems that’s what Shimano was striving for with GRX 12-speed mechanical groupset.

We have a groupset soon to be delivered for long-term testing, stay tuned for more folks.

ABOUT THE REVIEWER - Colin Levitch

Hometown

Gold Coast, QLD

Height

175cm

Weight

72kg

RIDING STYLE

Aggressively mediocre