Shimano GRX 12-speed (2023 GRX820/610)

I would love for a 1x derailer that was compatible with a 10-42 to a 10-50 cassette, or something like that. Please also use an existing BCD for the chainrings.


I hope that, in it’s 1x form, GRX 12 speed offers a middle-ground cassette similar to SRAM’s XPLR 10-44 cassette - there’s a YUGE jump from Shimano’s 11-36 to the MTB focused 10-45.

I read on another forum that SRAM Apex (coming soon) will introduce a standard HG 11-44 cassette with the first three cogs being 11,12,13 (so, effectively swapping XPLR’s 10t cog for a 12t cog). It’ll be all-steel too, which would wear way better than those cassettes with aluminium large cogs (dumb!.. especially on a 1x)

Hopefully this incentivises a similar offering from Shimano (if they weren’t already planning it).

As above, a single rear derailleur that can cope with the Shimano 11-36 cassette (for road) as well as a Shimano HG 11-44 cassette (for light to medium gravel) would be great for a dual-purpose bike with two wheelsets.

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Plus, the first 8 gears of the 10–45 cassette are identical to those of the 10–51 cassette, and I see no reason to not just go with the 10–51 cassette instead.

For some reason, Shimano has been reluctant to offer good 1x options. Just compare your 1x chainring options between Shimano and SRAM. I suspect they really believe 2x is better and just offer the bare minimum for customers interested in 1x. They got into real trouble for that in the mountain biking realm, where for a while SRAM’s popularity surged.

SRAM will sell you everything from 38 teeth to 54 teeth in 2-teeth increments. (Not that I recommend using a 54-tooth chainring on a gravel bike, but you get the point.) Shimano currently has 2. Ditto for cassettes. With 11-speed, Shimano contented itself with borrowing its 11-speed mountain bike cassettes.

I hope Shimano will change their mind with their 12-speed drivetrains. I just wouldn’t bet on it.

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I agree with all you’ve said, but I am holding out hope that it’ll be better than we think.

SRAM XPLR and eKar are light years ahead and Shimano must know they’ll lose out on sales if they don’t offer a genuine (read: decently geared) 1x all-road/“groad” option.

Time will tell! (Hopefully not too much time!)

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Yeah, I hope I am wrong, too.

I think it caught Shimano off guard when the MTB migrated to 1x. (Shimano still offers 2x mountain bike groupsets, but I have never seen them on any mountain bike.) I don’t think gravel cyclists will all flock to 1x the same way mountain bikers did, but from my observation there are 1x and 2x camps amongst gravel cyclists, and both camps are sizable. So sizable that many bike manufacturers offer many of their gravel bikes in 1x and 2x configurations.

While I don’t have any sales numbers, it is clear that 1x is a thing in the gravel community, and Shimano only harms itself by not catering to it. The best that can happen to us is solid competition between (at least) two solid players. So I’ll keep my fingers crossed, too.

PS Dear Shimano, while you are at it, add native power meter options, too. Thank you.


ADRIS, a french bike vendor has released a bike equiped with 2x12 speeds GRX 820 groupset:


Ive been running a Garbaruk 10-48 with an eagle derailluer and chain with 1x Red/quarq crankst and it has been flawless. Im amazed at how durable this setup is. Chain has 2000k on it and still nothing seems worn.

Any more news / rumors on this? Trying to decide if I should wait or move forward with a full Force AXS upgrade on my Crux.

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Trying to find the links, but I’ve seen a handful of different European bike brands list 2023 bikes with 12s GRX. Sounds like it will have a mechanical version as well as a Di2 version. Should be coming out fairly near term.

Along those lines, it also sounds like SRAM will be releasing Apex AXS this spring, as well as some rumors of new Force/Red shifters that are smaller (like the rival shifters) but also have hidden buttons similar to Di2 levers.


I’d love to have extra buttons. Not sure if I want the shifters smaller, though, I like that they are more substantial. (I haven’t tried Rival shifters, though.)

I want Bluetooth to garmin buttons

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This new GRX group is the one I want for my new gravel bike. 31 - 36 is :ok_hand:t3:

You can already run 31x36 if you use the sram 11-36 11speed cassette


Or have an even easier 30:36 if you went with SRAM.

It really makes me wonder how much further Shimano could be if they offered proper custom gravel cassettes rather than just their road (2x) and mountain bike (1x) cassettes on GRX. It seems they will continue to do more of the same. The only question mark will be their 1x12 gravel cassette. Their 10–45 cassette is, hmmm, not great.

You can use the 46/30 shimano with the 11-36 sram cassette too. Or the 11-40 if you need lower. The leaks already confirmed 11-36 but hoping to see another cassette or two

Still hoping for an 12 speed, HG, 11-40.


Man that would be an awesome cassette

Im a bit late to this thread, and I know this thread is about 12s, but currently running 11speed 1x on my Steel Frame Gravel/Commuter. Its fabulously comfortable to ride. Ultegra Road manual road shifters and GRX 42 and 11-42 rear cassette with GRX 812.

I need more gears for upcoming South American Adventure, Im thinking going back to 2x with GRX 48/31 and 11-34. Any issues with this. Grx works fine with the Ultegra Road shifters at the rear, see no reason why it wont work on the front. Im old and bit heavy so need the extra gears for the 20% plus gradients. :slight_smile:


My LBS just told me „GRX likely this quarter“ and they have „received some marketing material“. Dunno if that is accurate, but I’ve read something similar in a thread on Weightweenies.
You heard anything?


Could you not just use Shimano’s 11-46 cassette with an appropriately sized 1x chainring?