Shimano GRX 12s (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.