First rides on Shimano's new 1x12 GRX group set

Shimano have just released their second generation GRX group set – or more accurately, three different GRX group sets. Shimano have released three new 12-speed group sets that suit just about anything between road riding and mountain biking, delivering a wider gear range and better ergonomics than ever before. And the best news? They are all available right now.

Introducing Shimano GRX RX820 12-speed mechanical

The big news is that Shimano have brought GRX into their 12-speed family. This follows on from Shimano's 12-speed road group sets and of course XTR, Deore XT, SLX and Deore. There's even some considerable parts compatibility, for those chasing adventure bike drop bar builds.

All three GRX group sets are mechanical, although Shimano told us we can expect Di2 GRX 12-speed group sets in the future – but they weren't giving us any dates. Mechanical group sets have a lot going for them, with a lower cost of entry to a high quality group set designed for gravel and all-road use. It is easier to maintain when travelling, on multi-day trips or in crappy conditions. Interestingly, Shimano are determined that GRX RX820 12-speed isn't just for gravel bikes, so we reckon you'll see it being used on a wide range of drop bar bikes. This would be why their three new group sets in the 800 series offer so many choices.

Shimano GRX 1×12 with a 10-45t cassette: Unbeatable

Shimano storm the gates with the 1×12 group set that they say is 'unbeatable'. This GRX group set has been designed to deliver close gear ratios while still offering a wide range 1x group set. To achieve this Shimano match a 40t or 42t chain ring to a 10-45t 12-speed cassette, with a short cage (GS) Shadow Plus rear derailleur which has a clutch for chain security.

Like Shimano's mountain bike derailleurs, the derailleur sits out of the way. However this mech has a barrel adjuster on the cable entry, as a drop bar shifter doesn't have one. Shimano use a 12-speed Hyperglide+ chain from their current 12-speed equipment, so any 12-speed chain from Shimano will be compatible. The cassette is a Shimano M8100 XT model, so you could upgrade to an XTR M9100 10-45 if you wanted to shed some weight.

The shifters have a refined cable pull for faster actuation, and a new design that has been designed to work with flared drop bars to relieve hand pressure. Shimano went so far to refine the ribbed hoods to have just the right height (0.8mm) finding balance with grip and comfort. There's an option for a left shifter to work with droppers, which need to have the cable clamped at the dropper.

Shimano have also updated the calipers with a design that is more open to allow 10% greater clearance between the pads and rotors. This is great for drag free running and less than ideal conditions, to let much pass through a little more easily. Shimano's new IceTech CL rotors are part of the group. They have a new alloy carrier design that removes any slight warping at even the hottest temperatures. Sizes go from 140mm upwards with Centrelock attachment – expect to see this new design all the way up to 203mm rotors.

The Shimano GRX crank arms carry over, but with the updated chain rings for 12-speed. This is good news for those wanting to upgrade an existing bike, or use an existing crank based power meter.

Shimano GRX 1×12 with a 10-51t cassette: Unstoppable

This GRX 1×12 group set delivers the widest 1x gear range, with a 10-51t M8100 Hyperglide+ cassette working with a matching chain, still on a 40t or 42t chain ring. Shimano do also have a 38t steel chain ring. This could be just the ticket for fully loaded bikepacking trips.

This GRX group set uses a Shimano longer cage SGS rear derailleur. But if you swap from the 10-45 to 10-51 you need to change the lower cage – but not the whole derailleur. It's an item you can buy to swap out. It's still a Shadow Plus design to stay out of the way and with incredible security on rough terrain. The cranks, brakes and shifters stay the same as the other RX820 items as above.

Shimano GRX 2×12: Undroppable

Shimano haven't left the front derailleur in the dust. The Shimano GRX 2x group set sees similar updates with a shift to 12-speed. For those racing gravel, or those who choose the less beaten path on their all-road rides, the performance of a 2x group set is hard to beat. This group set carries the same updated brake calipers and shifters, a new 12-speed Shadow Plus derailleur, and a 31/48 chain ring pairing on the cranks.

The 11-34t cassette and 12-speed chain use Hyperglide+ for secure shifts up and down the cassette, and there is an 11-36t model for a little more range – although that cassette goes without the Hyperglide+ ramps and profiles. Shimano have also updated the front derailleur, and the derailleur sits 2.5mm further out which improves tyres clearance for wide tyres and mud – no doubt great news for anyone taking on demanding gravel events on the world stage.

The gear range chart is a good visual representaion of how the different group sets combine to offer really wide gear ranges.

New Shimano wheels

It's been a little while since we have seen a release from Shimano for wheels designed for dirt. Shimano have been renewing their wheel set range and their road wheels have lead the charge. But the new RX-880 TL are an exciting addition to the range. They're wide, light and low – making for the perfect partner on a gravel bike. With a 25mm internal rim they suit 32-50mm tyres, making them about spot on for what Australian gravel conditions present. 

The rims have a 32mm depth to aid the ride quality on rough terrain. The hubs use Shimano's cup and cone bearings, however you can have the wheels fitted with Shimano's Microspline freehub body to suit the 10t cassettes, or the new HG L2, which is a spline profile that Shimano introduced with Dura-Ace – but it is compatible with the 11-34 and 11-36t 12-speed cassettes as well. Both options bring the wheels under 1400g, making them a very competitive weight for a wheel set with this profile. They sell for $2199.

First rides on Shimano GRX 1×12

I was invited to the press camp in Bend, Oregon for the release of the new group sets. Our riding ended up limited due to heavy smoke from forest fires. Still, I had a few hours on the dirt with the 1×12 'unbeatable' group set.

Like any Shimano group set – it just works. It's Shimano. The subtle updates to the shifters make a difference in ergonomics, but I also noticved better shift actuation with a shorter throw. I also really liked the setup of the GRX cockpit on flared bars, it was very comfortable.

While Hyperglide+ is easy to look over, this is the shift security that really makes Shimano's 12-speed equipment shift so well. When it was introduced for mountain bikes with the Shimano 12-speed releases, it seemed simple in the presentation, until you keep shifting under load on the trail. And that's when you realise how precise the shifting is, with guided shifting up and down the cassette. Along with the Shadow Plus derailleurs it helps keep the chain shifting, and not slapping – and that counts on a gravel bike as much as any other bike.

We have a long term 1×12 group set and wheels on the way to swap out with the GRX 2×11 group set I bought to set up the Factor LS gravel long termer.

That long term review will be in the works, but for now Shimano Australia has all the parts in stock. 1 x 12 group sets start at a little over $2000, but we expect you will be seeing whole bikes with the 12 speed GRX equipment shortly as well.