Shimano GRX RX820 - New Gravel Groupset Goes 12 Speed!

Some of us have been runnj g a 51t cassette without mods since GRX came out. Albeit 11sp

GRX was such a clever product at launch and left an easy progression path with any new technologies.
Shimano pretty much cherry picked bits from their other road and off-road groupsets, but only using older 11 speed technology. I've had my GRX since 2020 and it has been a good product to use but has also had it's faults.

The chainset only take GRX specific rings.
My right shifter failed to shift recently.
Both brake calipers started to leak and were replaced wth Hope.

thepathlesspedalled will be happy to see the front mech still going strong. No friction option though?

Presumably one can run this with with an MTB chainset in 1x configuration. Another good option.

Let's hope for some 11speed deals 😀.

Let’s hope for some 11speed deals 😀.

Slight tangent - will 11spd GRX STIs work with an 11 speed XTR rear mech?

I'm more interested in Microshift Sword 2x10 and 1x10....

My GRX 815 DI2 has been utterly faultless on 2 bikes with a combined mileage of 25k km.  I’ve replaced 1 chain in all that time.

The 12s has some big shoes to fill.

will 11spd GRX STIs work with an 11 speed XTR rear mech?

Cable pull is different but you can use a tanpan to use 11 speed road/gravel shifters with MTB mechs

https://www.wolftoothcomponents.com/collections/drivetrain-1/products/tanpan?variant=18367738757

@daffy that's really impressive. I've done maybe half your distance and am on my 4th chain, second cassette, second chainring and third bottom bracket. I do like to ride in the winter slop though.

Will there be a 73mm BB option on the crankset?  There are quite a few gravel frames that have a 73mm BB shell, so an MTB crankset is often required.  I've but XT or SLX on both of my gravel bikes because the GRX ones won't fit.

Some of us have been runnj g a 51t cassette without mods since GRX came out. Albeit 11sp

The 812 (?) rear mech takes that without any hanger extenders or whatnot?

I was thinking of trying an 11-46t SLX cassette I've got spare. If that works I see no need for 12sp personally.

pretty sure there's quite a reasonable number of boost spaced gravel frames on the market now, which would mean any boost hub with miscrospline would work with this, on those frames? Unless this microspline is different to the microspline used on the 'mtb' kit....? And yeah, GRX specific chain rings are a bt of a pain still - I used a Praxis crank instead (Alba I think...) cos it has a removeable spider and uses the SRAM 3 bolt interface, so any number of 1x NW rings available for it. Bit of a mish mash of stuff - 'old' 11 spd GRX 600 mech and shifters, Praxxis crank and a Superstar 38T chainring. 11-46T XT cassette. Standard caliper on the back, but swapped out the front for a non-series shimano 4 pot caliper. seems to all work well together though!

The 812 (?) rear mech takes that without any hanger extenders or whatnot?

Yep

https://ukgravelco.com/2020/06/18/shimano-deore-cs-m5100-cassette/

Let’s hope for some 11speed deals

The 12 speed stuff is at whole different price point to the 11 speed stuff.

Scratch that... RRP is pretty close, isn't it.

+1 for the mechanical and keeping doubles approach but 48-31 is still a big chainset (and quite a gap between ring sizes)

Still waiting for something in the 42-28 range from Shimano. 10s MTB doubles were great for gravel bikes.

Yep

Cheers boss

The 10-51 1x12 new GRX uses the XT cassette and chain, so on a more drop bar mtb type bike you would just use an SLX, XT or XTR chainset and away you go.

Still waiting for something in the 42-28 range from Shimano. 10s MTB doubles were great for gravel bikes.

I have 46/30t GRX 10sp from Ribble's silly sale (£30).
Combined with a 11-36 rear cassette it is great on my do it all bike, even winching up hills with pannier on.
At some point I will add goatlink an an 11-40 cassette and have (albeit with larger jumps) full touring / off road winching ratios.

@james0 - and Ben Delaney was complaining that the single ring options don't go big enough. UK wants lower ratios, US wants higher? We're a tough crowd...

Still waiting for something in the 42-28 range from Shimano. 10s MTB doubles were great for gravel bikes.

I've got an XT M785, 175mm, 40-28T in Black BNIB (a posh box, too) if that would help anyone?

I have 46/30t GRX 10sp from Ribble’s silly sale (£30).
Combined with a 11-36 rear cassette it is great on my do it all bike, even winching up hills with pannier on.
At some point I will add goatlink an an 11-40 cassette and have (albeit with larger jumps) full touring / off road winching ratios.

I don't mind larger jumps at the back but I prefer a smaller gap at the front. When the jump up front is bigger the compensation shifts are needed and the whole thing seems a faff Vs 1X. I rarely need higher than 42x11 on a gravel bike and with 11-34 at the back a 40 or 42 is used like a 1x8 or 1x9 most of the time, with a lower 1x option for climbs, loaded riding etc. So the 28-40 XT I've been on for a while is really nice, you shift up front and often don't need compensation at the back. Anyway.. subjective stuff, not saying it's better, just that the range of choice isn't great.

Ben Delaney was complaining that the single ring options don’t go big enough

I'm man enough to be seen with smaller rings and do ok on them : ) I just don't need to pedal past about 25-28mph on a gravel bike, or at least not for long and there's no sprints for bragging rights on my rides.

I’ve got an XT M785, 175mm, 40-28T in Black BNIB (a posh box, too) if that would help anyone?

I would but I'm on 170s. If you sell the arms I'd take the rings.

Gravel riding in the USA ≠ gravel riding in the UK.

thepathlesspedalled will be happy to see the front mech still going strong. No friction option though?

Hasn't Russ endorsed another friction shifter for precisely this sort of application?

Edit- here you go Soma/dia compe apparently:

Glad they're kept mechanical shifting, also glad to hear mechanical shifting 105 is out (hydraulic disc braking only though).

I will of course be browsing old 11 speed GRX prices now of course because new and shiny with a bonus click means the old stock getting run out at more affordable prices...

Of course one thing is missing from the autumn hype train (so far), where's the promised CUES for drop-bars eh? Staggered embargo or just not a priority?

use an SLX, XT or XTR chainset and away you go

10T gap's a bit small. Fussy aren't I ... but it's no issue, I just buy AM rings for my own bikes.

I think OEM and AM spec could be a bit wider in this area but I also think Shimano do more customer research than I do so I'm probably an outlier. I do see a lot of people walking gravel bikes up hill that aren't really that steep/hard and some of that is gearing, but there's solutions in what's available already.

I think OEM and AM spec could be a bit wider in this area but I also think Shimano do more customer research than I do so I’m probably an outlier. I do see a lot of people walking gravel bikes up hill that aren’t really that steep/hard and some of that is gearing, but there’s solutions in what’s available already.

I don't think you're an outlier, I think Shimano are often quite conservative and know stretching ranges to win the numbers game could result in more returns. Gravel bikes with 'sub-compact' 2x make a lot of sense, I think lots of people/companies are still feeling out the ratios though.

I think OEM and AM spec could be a bit wider in this area but I also think Shimano do more customer research than I do so I’m probably an outlier. I do see a lot of people walking gravel bikes up hill that aren’t really that steep/hard and some of that is gearing, but there’s solutions in what’s available already.

I am not sure you are an outlier.
I wonder, and you will know more about this, if there is an issue of product managers in big corporations such as Shimano looking at US or Asian gravel and riding more than UK/European riding. They need to understand steep and slippery hills more.
And perhaps I would also say there is an issue with companies specifying things - basically so many gravel / do it all bikes come with CX gearing. Road gearing seems fixated on what a professional rider would use, not your average fitness punter. Therefore so many of these gravel / do it all bikes come either way over geared or 1x because 1x.

I too would prefer a slightly smaller jump on front rings, avoiding that downshift at the back when you swap, and put up with some bigger jumps at the rear. Maybe 46/36 and an 11-42...?

I'm a fan of the spa-cycles approach:

"Super compact"

Basically take your old touring 3x, 110/74 BCD crank play with the inner/middle rings to give a range of 16T difference options and lengths, bolt on a dorky bash guard than most punters will remove immediately then double the asking price...

Personally I'm more tempted to buy this in 170mm and and this in 42t for use with an 11-36 or 11-40 cassette. But I'm weird and don't see a problem with square taper BBs.

and Ben Delaney was complaining that the single ring options don’t go big enough. UK wants lower ratios, US wants higher? We’re a tough crowd…

The same Ben Delaney who reviewed the new Santa Cruz Stigmata as ground breaking with its clearance and slacker head angle and when I asked how it was different to what some gravel bikes have had for around 3 years he couldn't answer.....wait, he did say it had a door in the down tube.....yea Ben, no one's done that before have they!

Shimano do more customer research than I do

Both shimano and sram are well behind the curve on crank length offerings, 165mm cranks are still like hens teeth, while many riders are now wanting even shorter. So I don't actually think they are aware of the market so much as they expect to be able to dictate that the market.

Gravel riding in the USA ≠ gravel riding in the UK.

That there is the problem.

Good that the group can now be mixed with Shimano 12 spd MTB chainsets for lower ratios.

Those who want bigger ratios can fit bigger tyres....

Sadly I’m so use to to Shimano getting the chainsets wrong I’ve sort of ignored it.

I’m not sure why shimano can’t see that consumers want flexibility. There are clearly people happy are happy with a bottom gear of 30x36 or 40x42. But that doesn’t work for me. My gravel bike is 26x36 with a spa cycles sub compact and 650b wheels. I could go lower particularly if I had bigger wheels.

In the summer I road a today gravel event in Wales. People were on a wide range of bikes. But we all went up the same hills. Non were technical and the MTBs were using their gears down to say 32x50. No idea why any one think that those on drop bar riders wouldn’t want the option of a similarly low gear

Gravel riding in the USA ≠ gravel riding in the UK.

Yep the US have gravel roads that hit 13,000 ft. Should the group sets really be based on a narrow spectrum of flatish well published races. Rather than say the Tour Divide. I think I read that there were no Di2 bikes in this years event. Loads on sram electronic shutters apparently. Presumably, in part, because the riders on drop bars can use it to access MTB gearing

Another daft tiny cog.

Why not run something like a 13 up? You could go slightly smaller on the front as  and thus a smaller bottom gear . Of course run 2x so you don't have those silly gaps.

11-51 cassette, GRX rear mech and brifters XT crank with 36t ring

https://flic.kr/p/2o4bAZf

Just confirming @rocketdog's comments on 51t cassettes already being compatible with GRX, albeit on mine I used a Garbaruk cage. Shifts perfect, indiscernible from factory derailleur. 36x51 gets me up anything in Shropshire, with the only limitation being pie intake and lack of fitness. I'd post of pic but it's a PITA.

Here's a question, the new road/gravel 12 speed mechanical is it still using the same cable pull? Would the RX820 mech be backwards compatible with 11/10 speed levers?

It's not like 10 and 11 speed cassettes in wider ranges aren't available and if you've got perfectly good levers already, are people really that bothered by the extra sprocket?

I was hoping they’d release this in di2 soon, I have 11 speed GRX mechanical on one of the gravel bikes and it’s a bit tired. Think I’ll hang off for electronic and just replace chain for now.

other gravel bike has 12 speed GX AXS and Rival AXS etap  groupset  and is nicer on the gear side, but I hate the brakes !

Here’s a question, the new road/gravel 12 speed mechanical is it still using the same cable pull? Would the RX820 mech be backwards compatible with 11/10 speed levers?

yep we need to know that….

I wonder, and you will know more about this, if there is an issue of product managers in big corporations such as Shimano looking at US or Asian gravel and riding more than UK/European riding. They need to understand steep and slippery hills more.

Not 100% sure, I don't think so - but probably safe to say they won't see the 'UK gravel' approach of underbiking on MTB terrain to the extent that happens here, as part of 'gravel'. I'd say they're right tbh, gravel bikes get lost when they're trying to be more MTB and become bad all-road bikes (imho). Alternative chainset ratios are just for loaded riding or long days with steep hills. And part of my wish for sub-compacts is aesthetic, that I don't really want a 10-51 and a massive mech on the back of my own gravel bikes. 12-36 is fine with a reasonable 2x chainset spec. It's all so variable + subjective though, hence why I would like a bit more choice.

"I think I read that there were no Di2 bikes in this years event. Loads on sram electronic shutters apparently. Presumably, in part, because the riders on drop bars can use it to access MTB gearing"

I know that Shimano was teasing/testing pre-launch GRX mk2 at Unbound, so any Shimano sponsored riders (who might usually use Di2) were probably asked/obliged to try the new mechanical stuff. I have a mix of Ultegra/GRX Di2 on my 'cross bike and would view it a bit of a downgrade to go back to mechanical (not least because of the faff of re-cabling everything). 😮

My GRX 815 DI2 has been utterly faultless on 2 bikes with a combined mileage of 25k km. I’ve replaced 1 chain in all that time.

25000km off road on 1+ chains? What wear did you replace at and how worn is the current chain?

Based on your other posts on here I have no reason to doubt your word, but still, that seems pretty hard to believe? I don't think I've even achieved half that chain life on a summer road bike with a waxed chain! (Squirt rather than immersion, but still) let alone a gravel bike chain (you use Viking Juice yeah?).

I cam here to comment on GRX but then realised that the only GRX component I actually run is the chainset and I still haven't figured out the best combo of rings for that! Problem with GRX for UK gravel is you basically need the range of MTB gearing through to road gearing. Might as well bring back triples! 😂

Might as well bring back triples

I put a triple on a garage spares bike build earlier this summer. Bloody amazing!

I cam here to comment on GRX but then realised that the only GRX component I actually run is the chainset and I still haven’t figured out the best combo of rings for that! Problem with GRX for UK gravel is you basically need the range of MTB gearing through to road gearing. Might as well bring back triples! 😂

I had the same issue with gearing when I was building up my Three Peaks CX bike - first build was way before GRX was on the scene, I've upgraded it a couple of times since.

I'm running a 34/48 Rotor chainset with a 10so cassette (11-36) which gives the range of gearing low enough for most off-road and high enough for road. A 31/48 GRX chainset would be preferable.

I'd like to go to an 11sp Di2 set up because the cable routing (early days of internal!) is enough of a pain that getting the rear gears sorted is a nightmare. But I guess if I'm going down that route, it'd be easier to just get a new bike.