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TECH NEWS
Shimano GRX gravel/adventure groupset launched - all the key details you need to know
It’s been a long time coming, but after teasing with Ultegra RX last year, it’s finally here, Shimano has announced its first dedicated groupset aimed at gravel and adventure bikes. Called GRX, the new offering provides a wide spread of possible builds including 10 and 11-speed, 1x and 2x, mechanical and electronic, wide or close-range gears and dropper post integration.
Shimano hasn’t just rushed into the gravel market. Oh no, that’s not the Shimano way. It has taken time to research, test and develop products that it feels meet the feedback it has been getting from riders around the world embarking on the new wave of adventure, bikepacking and gravel riding. And what it has developed is a groupset that is as adaptable as the bikes it’s designed for.
The GRX groupset will be offered in RX800, RX600 and RX400 series (800 being lighter and 11-speed) with 1x11, 2x11 and 2x10 drivetrains and mechanical and Di2 electronic shifting options so you really can pick a groupset configuration that meets your needs. Don’t like front mechs? Go 1x11. Prefer the wide range of a double chainset and want to stick with 10-speed? You can do that too.
“Developing the series took Shimano’s development team well outside traditional confines to create a platform that addresses riders’ needs now and into the future. Be it gravel riding, modern adventure road riding, bikepacking, or fulfilling the needs of discerning cyclocross racers, Shimano GRX provides options ranging from gravel-tuned gearing ratios to custom ergonomics, from dropper post integration to gravel-specific GRX wheels with wider rim profiles,” explains the company in its press release.
The new groupset includes cranksets, front and rear derailleurs, STI levers, a new sub-brake lever for braking on the tops, disc brake calipers and wheels. The top-end 800 series can be mixed with the more affordable 600 series components.
“This means that you can create everything from a light-weight racing-level GRX stead at the premium level to a leisure-riding GRX workhorse at the more economical level,” says Shimano.
Cassette and chain options will come from current road (105, Tiagra, Ultegra) and mountain bike (Deore, SLX, XT) groupsets.
Let’s look at the new groupset in detail and break it down into each component family.
Crankset options
There are three cranksets to choose from - 1x11, 2x11 or 2x10-speed - and each has a +2.5mm chainline for increased tyre and frame clearance.
The GRX double chainset is offered with 48/31 and 46/30t options with a 17 and 16t gap respectively between the two rings.
The single ring chainset employs Shimano’s Dynamic Chain Engagement tooth profile to prevent the chain bouncing off on rough terrain.
Claimed weights are as follows:
- 1x11: FC-RX810-1: 655g FC-RX600-1: 753g.
- 2x11: FC-RX810-2: 722g, FC-RX600-11: 816g, FC-RX600-10: 819g.
Front derailleur
SRAM might be on a mission to kill off the front mech, but Shimano still firmly believes in the benefits it provides, and the new GRX groupset can be had with a front mech in either mechanical or electronic flavours.
Compared to regular road front mechs, the GRX front derailleur has an additional 2.5mm outboard clearance to provide space for wider tyres, up to 42mm.
For this reason the front mech must be used with the matching GRX chainset which is similarly pushed out by 2.5mm from the frame.
GRX front derailleur weights:
- FD-RX815-F: 131g
- FD-RX810-F: 94g
- FD-RX400: 95g.
Rear derailleur
As you might expect, the new GRX rear mechs are based on the Ultegra RX mechs that were launched last year, and which gave the first indication Shimano was looking at the gravel and adventure bike market.
As such, the rear mechs use the company’s Shadow+ technology which helps to minimise chain slap provide more secure chain retention and a quieter ride.
There are four rear derailleurs wearing the GRX label, a short and long cage option in both mechanical and Di2. Short cage for 11-30/34t cassettes and long cage for 11-40/42t cassettes.
GRX rear derailleur weights
- Di2: RD-RX815/RD-RX817: 288/322g
- Mechanical: RD-RX810/RD-RX812: 251/264g
STI brake levers
There are dedicated GRX levers, mechanical and electronic, which use a “gravel-specific ergonomic” lever design.
The hood shape is 18mm taller to provide a more secure hand position on rough ground, essentially to act as something to butt your hand up against to stop it sliding over the top of the hood, with a bigger scoop in the centre of the brake lever along with an anti-slip textured finish to provide a more positive finger/lever engagement.
If your gravel riding is getting rowdy and you want/need a dropper post, Shimano has developed a dedicated left-hand shifter that is compatible with cable-operated dropper posts with a 9mm lever throw.
There’s also a 1x11-specific hydraulic disc brake lever with no shifter internals, as well as a Di2 left-hand shift in which the three buttons (two on the lever, one on the hood) can be used to operated accessories like a computer or lights.
If you want more braking power, the top-end RX815 brake lever utilises the company’s Servo Wave technology from its mountain bike brakes which it claims provides a stronger braking feel with more modulation.
The regular RX180, RX600 and RX400 brake levers are closely comparable to Ultegra, 105 and Tiagra hydraulic disc brakes.
GRX STI shift/brake lever weights: ST-RX815-L/R Di2: 565g, ST-RX810-LA Left side dropper post lever: TBDg, ST-RX600-L/R: 611g, ST-RX400-L/R (10-speed): 613g
An interesting option that we’ve not seen since ye olde cyclo-cross days, and trialled by Hope a few years ago, is the new inline hydraulic sub-brake lever.
The RX812 lever attaches to the handlebar tops alongside the stem and connects to the front and/or rear brake caliper and basically gives you the option of braking when riding on the tops.
We can certainly see many situations when this would be useful to have, and chuck in the Di2 satellite shifter buttons and you could change gear and brake while on the tops.
Cyclocrossers and cobbled classic racers will also potentially find this an interesting option to have, so we expect to see it popping up a lot over the near year or two.
GRX hydraulic disc sub-brake lever weight
- BL-RX812L/R: TBCg
Brake calipers
The flat mount brake calipers use the same design as the current road calipers but are stickered with GRX logos.
GRX calipers weights:
- BR-RX810: TBCg
- BR-RX400: 143g
Wheels
Rounding out the new GRX range are two sets of wheels with a choice of 700c and 650b sizes.
Both wheels are designed for the rigours of gravel riding with a wide 21.6mm internal rim width, a 22mm deep rim and 12mm thru-axle hubs.
GRX wheelset weights:
- WH-RX570 700c: 1600g/pair
- WH-RX570 650b: 1540g/pair
How much is it?
Prices haven't been confirmed yet but we'll update this article as soon as we get them.
Summary
We’re impressed with what Shimano has delivered. It’s been a long time coming but Shimano has finally entered the growing gravel and adventure market with a well-considered range of options that should keep even the most demanding gravel cyclist happy.
The range of options would appear to be ideal for those speccing their own gravel and adventure bikes, as well as giving bike brands plenty of options when it comes to building new bikes for the 2020 and beyond model years. The decision to offer three ranges with 11- and 10-speed will ensure it’s an accessible proposition too.
And finally it means sensible gearing for Shimano-equipped bikes, so hopefully no more compact 50/34t chainsets on gravel and adventure bikes.
We’ve not seen it in the flesh, or should that be forged metal, yet, but hopefully we can get a closer look at it soon and maybe even get a groupset to put it through its paces. But which configuration to go for?
If you like what you see and want to get your hands on GRX, you’ll have to wait until June for mechanical and August for Di2. More at www.shimano.com
David worked on the road.cc tech team from 2012-2020. Previously he was editor of Bikemagic.com and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds, and you can now find him over on his own YouTube channel David Arthur - Just Ride Bikes.
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31 comments
Does that inline lever work with the whole GRX range? Or, for that matter, the road hydros? It doesn't even feature on the compatability chart on the Shimano site.
It'd be great if it does work with road hydro setups, for the in town part of my commute an option to use the tops for a more heads up position but still have brakes easily accessible would be really useful.
Does it mean you have four seperate levers to bleed or all in one go?
I like the idea of gravel riding, and indeed have done a bit of it on drop bars from time to time. But at the same time, whenever I'm doing it it, I always have the same thought which is this.:
"this is fun, it's like the old days riding a rigid/short travel 26-er xc bike around on forest trails & bridleways before new Mountain Bikes made all that really easy but also a bit slow."
Therefore I have to ask, is gravel riding filling a niche that all of us who used to love mountain biking but couldnt give a stuff about bike parks, enduro and downhill used to fill?
Probably a question for Dave, given his extensive back catalogue of bikes tested over the years, but how do all the new gravel bikes compare to riding say, a classic De Kerf softail, or Klein attitude with a Pace carbon rigid fork in terms of fun factor and versitility?
I've got a Whyte Glencoe; fat 650b tyres and drop bars and whenever I'm offroad on it I channel my inner John Tomac. That's my era.
This is it for me - I'm fortunate to live on the edge of Cranborne Chase/Salisbury Plain so I've got miles and miles of rolling bridleways and the like. Not really gravel, more flinty chalk than anything. Have no desire to lob my body down singletrack or tool around in bike parks, it's about getting off the road and seeing the countryside. Sort of rambling by bike I guess. Steel tourer, flat pedals, disc brakes, and panniers are the order of the day, so the bike must be well north of 15kgs.
The terrain requires low gearing because I'm pushing a 40mm tyre and the inclines are long, straight, 6-8% climbs, often through thick grass. 34/34 just isn't low enough at the moment and I don't want the added faff of a triple.
I've currently got a 4iiii Precision 6800 Single Sided power meter.
Is there any reason that this shouldn't work with this groupset?
Should be just fine
Clearly not bothering with rim brake gravel bike users, they could have developed a set of calipers that can take a wider tyre and not be flexy, I mean, considering the amount of R&D put into discs this shouldn't have been more than 10 minutes on the back of a fag packet.
Also 46/30 is okay but still relies on you having a dustbin lid cassette at the back and as they've stated it's going to be road cassettes, the 30T ring might not even be low enough for some and the terrains they are going on. I struggle to get up some gradients on the tarmac in 24/28, that's equivalent to 30x36, why not go to a 28 or even consider utilising a triple, at least with the triple you can get really low gears without having the stupid jumps when using cassettes over 32T
I've kept back some Stronglight 86mm BCD rings and can run a 48/28, with a Suntour 6 speed 14-32, means I can have a retro set up on my 60 year old bike and still go off road/get up some tougher routes.
Not sure the changing of the hoods is all that relevant, not when roadies are going to be in the drops right and indeed the previous gen was supposed to have resolved the grip issues with the ridges on top of the hoods anyways. Now just looks fugly as.
As for the chainline, funny how I'm already running a road bike from 2007/8 that uses a road set up - Ultegra triple with Miche Evo chainset, and I can have up to 55mm tyres, 42mm with mudguards easily oh and no discs. Dunno what the fuss is about tbh.
Firstly, they've said you can use either MTB or road cassettes - there are longer cage rear mechs supposedly for the larger MTB sized cassettes, but looking at capacities and Shimanos previous ability to accomodate more than spec'd, I doubt it will even be an issue, or one that a hanger extender or reversed/longer B-tension screw would cope with.
Even if you only used road cassettes though, Shimano 11-speed road cassettes go up to 34T (mixed road/MTB non-series CS-HGx00).
And as I said, wider range cassettes have drawbacks, the huge jumps in the ratios particularly when in the lower gears which is when you want to keep your rhythm/cadence as you're pushing hard. The big arse rear mechs are already overtly long, I just don't see this as a good solution for low gearing never mind when you're transitioning on varied terrain which is what you do a lot on 'gravel' riding.
It's relevant. When you're riding over rough terrain it really helps if the shape of the hoods retains your hands when you're getting jolted.
I'm not sure if this is a masterstroke from shimano or a compatibility nightmare!
I've stuck at 10 speed, the shorter chain life compared to 9 speed is noticeable, so 11 never appealed. But mtb vs road cross-compatibility is confusing, then tiagra had a new actuation ratio and ugly hydros.....
This groupset looks quite nice, rugged without being too ugly. A wider chainline makes sense with the wider hubs on disc bikes and wider tyres. A 48 big ring would be great on the road bike, the smaller inner is needed for off road and touring. Maybe this config finally replaces triples for general purpose bikes.
The moved brake pivot should be better for riding on the hoods too.
But I'm confused about compatibility. Is the pull ratio road or mtb, front and rear? Are the chainrings mtb pattern? Are the 10 an 11 speed parts compatible? What is this servo wave braking? It sounds sensible, but a compatibility nightmare!
I miss the days when road and mtb were generally switchable across speeds.
First person to add a power meter to a full GRX setup wins. No road cleats. (That would be cheating.) And no re-lacing the GRX wheelset with a replacement hub. Gravel/CX riders often have multiple wheelsets for various road conditions.
RX810 is Hollowtech II, not forged like the others, so the existing left-side crank arm power meters _should_ work i'd have thought - not technically then a full GRX setup admittedly, and not had anyone confirm the splines are fully compatible, but i'd not bet against it.
Not sure why this article dropped off the front page almost immediately?
Presumably then, if the new grouppo works with existing chains/cassettes and the rear mech is based on Ultegra RX, then it would be possible to mix GRX with current Ultegra, for example? So if you wanted to fit a GRX chainset to a bike with full Ultegra, then this could work to get lower gearing if you adjust for the extra chain offset? I’d imagine though if this does work that a GRX chainset would require a dedicated GRX bottom bracket?
And in 2x configuration, a GRX front mech, according to the article.
The chainline is moved out 2.5mm to allow for wider tyres. Shimano say you have to use the GRX FD to allow for this. They haven't shown any new bottom bracket in the group, so presumably the offset is wholly within the crankset. You could fit Absolute Black chainrings to the Ultegra crankset to give 46/30 for example, if you're just looking for lower gearing. Fit an Ultegra 11-34 cassette as well (this is what I've done).
Yep - seems that you still use a regular Hollowtech II bottom bracket, e.g. BBR60. Not sure exactly how much total outboard adjustment is available on the existing road front mechs, doubt it'll be enough but I might try and have a look this weekend at the 6800 front mech on one of the bikes.
That' s pretty much what I've done. AB 46/30 ovals on an R7000 crankset with 11-34 out back. Initial reaction is that going oval is perhaps "worth" another tooth or two in terms of perceived reduction of effort.
On another bike I've also got conventional round 46/30 rings on the inner two positions of a triple, with a chainguard on the outer. To my mind it's a good choice of sizes at the front.
48-31 would be good too - if they made something like a 12-36 cassette.
Prb worth pointing out that the long cage rear mech, and the bigger cassettes, can only be used 1x. So you cant do a double crankset with an 11-40 at the back. Apparently.
Well in that case use the XT range either mechanical or Di2. Combine with their new lower GRX chainset.
Ive mixed and matched different gearing with XT/XTR Di2 to give me a triple front 48/36/26 and if I want(and do) use a 11-40 cassette. All syncroshift setup for minimal chain deflection.
Which is exactly what I want to do - according to the Shimano website matrix, Di2 will run a 46/30 600 crankset with an 812 RD with an 11-40. Jobs a good 'un for me, been waiting for this for years. Currently running a Sugino 46/30 with an Ultegra 11-34 on eTap (shouldn't work, but does), but old knees and big hills need a lower bottom gear and this will do it perfectly. Actually gives me a similar bottom gear to my old 3x touring set up, so I can see this appealing to a lot of tourers as well.
46/30 & 48/31 up front? Great, at last!
But "Cassette and chain options will come from current road (105, Tiagra, Ultegra) and mountain bike (Deore, SLX, XT) groupsets."
So they'll all start with an 11 tooth ring.
I'm still (quite un-necessarily) spinning a 46x11 gear at well over 50kph (downhill I hasten to add)
Really Mr Shimano, when are you going to cotton on that many of us would happily forgo the 11T sprocket and start at 12 or even 13? ISTRC even James Hayden has to cobble his own cassettes together to get the gearing he wants for the Transcon...
Yay, another dark-coloured groupset from Shimano. From Dura-Ace to Claris, by way of this and the updated Tiagra, all their groupsets nowadays are some variation of gloss or brushed black, apart from a dull-looking "silver" option for 105 you'd be lucky to be able to buy or specify on a new bike.
<yorkshireman>When I were a kid, bike components were chrome, and so reflective you could comb your hair looking in the mirror that was your brake levers. But you tell the young people of today that, and they won't believe you.</yorkshireman>
Seems like an awful lot of effort to avoid making "road" levers with "mountain bike" cable pull or vice-versa.
Thank you, I stand corrected.
Nice sub brake lever.
I cannot think of anyone else using an odd number of teeth on the front rings.
Easton has a 47/32 direct mount "gravel" chainring set. And, of course, there's the ubiquitous 53/39 road crankset.
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