Shimano 12s GRX RX820/RX822/RX610, cable pull actuation ratio 11s/12s compatibility

[pdlpsher1]

So.... is the HWYABL00S1961S the correct part to convert the road DT Swiss 350 hub for the SHIMANO XT CS-M8100-12 Speed Cassette 10-51T?

Correct.

[UltraMaraFun]

I have a set of the Vel GRL 35 carbon wheels, and just been advised by Sigmasports that VEL have discontinued the Shimano MS Freehub body for my wheelset. So what are my options if i want to go 1x on new GRX with the 10-51 cassette? Alternatively, I assume the new 2x will also work with an 11-40 cassette as 11 speed GRX/105 does, but does anyone make a 12 speed HG compatible 11-40 cassette?

[ooo]

XD freehub 9-11-13-15-17-19-22-25-28-32-38-45 cassette advertised as shimano compatible (9-45T 500% vs 510% 10-51T)

https://www.ethirteen.com/collections/gravel-cassettes/products/helix-r-12-speed-gravel-cassette

Helix Race Gravel 12-speed, 500% Range, 310g-330g

The Helix Race 12-Speed 9-45T cassette extends legendary Helix shift performance and cross compatibility with SRAM and Shimano 12-speed drivetrains, to the light weight Gravel and XC marketplace.

Excellent shifting with Shimano and SRAM systems without compromise

[ultimobici]

XD freehub 9-11-13-15-17-19-22-25-28-32-38-45 cassette advertised as shimano compatible (9-45T 500% vs 510% 10-51T)

https://www.ethirteen.com/collections/gravel-cassettes/products/helix-r-12-speed-gravel-cassette

Helix Race Gravel 12-speed, 500% Range, 310g-330g

The Helix Race 12-Speed 9-45T cassette extends legendary Helix shift performance and cross compatibility with SRAM and Shimano 12-speed drivetrains, to the light weight Gravel and XC marketplace.

Excellent shifting with Shimano and SRAM systems without compromise

Pretty sure claiming cross compatibility with Shimano & Sram 12 speed and “Excellent shifting with Shimano and SRAM systems without compromise” are mutually exclusive claims. Which is it?

Speaking as someone who has several wider range 3rd party cassettes on a Shimano system I know expecting a Shimano mech to play perfectly with a smaller top sprocket cassette is idiotic.


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[ooo]

So I'm still waiting the compatibility report with RX812 on 12s STI and RX822 on 2x. RX812 is the rebrand M8000 GS, it can compatible with 2x or 3x FC and 46t CS, even 50/51/52 tooth by modifiction.
I'm not sure the pull ratio of 12s, I have 11s FD, RD and shifter. It's really annoyed.

We are still more interested :mrgreen: :mrgreen: in knowing the compatibility of the 12 levers (GRX-105) with the previous 11 rear derailleurs.....

ScaryAntelope tested this and 11 and 12 speed road/gravel cable pull actuation ratio is approximately the same:



2 pictures + video (12s grx RD with 11s cassette 11-51 with 11s shifter, credits: ScaryAntelope):
https://imgur.com/a/0dm2ZuF

[satanas]

My suspicion is that the 11 & 12 speed GRX RDs are the same apart from cosmetics, and perhaps jockey wheels. I should have an RD-RX820 to test soon, and am hoping it can handle a 42T rear cog as the 11 speed version will...

[ultimobici]

My suspicion is that the 11 & 12 speed GRX RDs are the same apart from cosmetics, and perhaps jockey wheels. I should have an RD-RX820 to test soon, and am hoping it can handle a 42T rear cog as the 11 speed version will...

Nope. Not even close. You may be able to get them to work passably but they are different.


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[Beetrootman]

Hello, in order put this to rest. I have tried an 11 speed RD-RX812 derailleur (with the long cage modification) paired with a 12 speed ST-RX820-R lever and a 11-51 cassette, it does not work. The pull ratios of the 11/12 speed derailleurs are not the same, and the parallelogram movement to track the cassette is way off.
I have switched to a RD-RX822 SGS derailleur and shifting is flawless now. I would not bother to try mixing and matching 11/12 speed GRX components if you want good shifting.