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

[ooo]

03.11.2023 update - cable pull actuation ration compatibility info:
viewtopic.php?f=4&t=172269&start=240#p1836309

update:

grx 12s rear deraileur compatibility with direct mount hanger:

RD-RX820: DM hanger compatible
RD-RX822-GS: DM hanger NOT compatible
RD-RX822-SGS: DM hanger NOT compatible

grx 12s chainrings:

1x12 FC-RX610-1 40 and 38 - new size (there is no 38 for 1x11 grx)
1x12 FC-RX820-1 42 and 40
2x12 FC-RX610-2 46-30
2x12 FC-RX820-2 48-31

grx 12s shifters:

2x12 ST-RX610 (1x12 BL-RX610-L)
2x12 ST-RX820 (1x12 BL-RX820-L ST-RX820-LA)

grx 12s wheels:

WH-RX880 microspline - compatible only with 12-speed mtb cassettes, there are no grx microspline cassettes
WH-RX880 non-microspline - first non-dura-ace wheels with 12-speed shimano road specific freehub body HG spline L2
(compatible with 12-speed road cassettes and CS-HG710; NOT compatible with 11-speed road cassettes and CS-HG800)

12-speed GRX part list:

Wheel Set Gravel SHIMANO GRX:
EWHRX880LFERED70
EWHRX880LFEREDMS70
WH-RX880-700C 12mm E-thru Tubeless For 12-Spd 100/142mm
WH-RX880-700C 12mm E-thru Tubeless For 12-Spd 100/142mm Micro Spline

Front Derailleur Gravel SHIMANO GRX:
IFDRX820F
FD-RX820 12-Spd Down Swing Down Pull Brazed-On For 48T

Rear Derailleur Gravel SHIMANO GRX:
IRDRX820
IRDRX822GS
IRDRX822SGS
RD-RX820 12-Spd Direct Attachement
RD-RX822 GS 12-Spd Direct Attachement
RD-RX822 SGS 12-Spd Direct Attachement

Disc Brake Assembly Gravel SHIMANO GRX:
IRX8202DRRDSC170A
IRX8202DLF6SC100A
IRX8204DLF6SC100
BR/ST-RX820 12-Spd J-kit w/ Fin Rear
BR/ST-RX820 J-kit w/ Fin For Double Front
BR/BL-RX820 160mm J-kit w/ Fin For Single Front

Disc Brake Gravel SHIMANO GRX:
IBRRX820F6RF
IBRRX820RDRF
BR-RX820 Hydraulic For 160mm Rotor w/ Fin Front
BR-RX820 Hydraulic For 160mm Rotor w/ Fin Rear

Chainwheel Gravel SHIMANO GRX:
IFCRX8201CXB0
IFCRX8201DXB0
IFCRX8201EXB0
IFCRX8201CXB2
IFCRX8201DXB2
IFCRX8201EXB2
FC-RX820-1 w/o BB 40x170mm 12s
FC-RX820-1 w/o BB 40x172.5mm 12s
FC-RX820-1 w/o BB 40x175mm 12s
FC-RX820-1 w/o BB 42x170mm 12s
FC-RX820-1 w/o BB 42x172.5mm 12s
FC-RX820-1 w/o BB 42x175mm 12s

Chainwheel Gravel SHIMANO GRX:
IFCRX8202CX81
IFCRX8202DX81
FC-RX820-2 w/o BB 48x31x170mm 12s
FC-RX820-2 w/o BB 48x31x172.5mm 12s

this is gravel specific part list, other components are shared from road and mtb groups

see also: 105 R7100 mechanical part list

[Woland]

Rear Deraiof lleur Gravel SHIMANO GRX:
IRDRX820
IRDRX822GS
IRDRX822SGS
RD-RX820 12-Spd Direct Attachement
RD-RX822 GS 12-Spd Direct Attachement
RD-RX822 SGS 12-Spd Direct Attachement

A quick google search suggests that the GS derailleur has a capacity of up to 45t and the SGS up to 51t.

[ooo]

RD-RX820 for 2x12 with 11-36T or 11-34T
RD-RX822-GS for 1x12 with 10-45T
RD-RX822-SGS for 1x12 with 10-51T

[ultimobici]

RD-RX820 for 2x12 with 11-36T or 11-34T
RD-RX822-GS for 1x12 with 10-45T
RD-RX822-SGS for 1x12 with 10-51T

No Di2 variations yet?

[RDY]

RD-RX820 for 2x12 with 11-36T or 11-34T
RD-RX822-GS for 1x12 with 10-45T
RD-RX822-SGS for 1x12 with 10-51T

Probably means that the GS will work in 2x12 50/34 with that tasty looking Ingrid 11-44 cassette ...

[ooo]

no hints on di2, except one unreliable source
no weightbtet
pricelist:

€50 FD-RX820
€105 RD-RX820, RD-RX822 GS/SGS

€365 BR/ST-RX820 12-Spd J-kit w/ Fin Rear
€360 BR/ST-RX820 J-kit w/ Fin For Double Front
€320 BR/BL-RX820 160mm J-kit w/ Fin For Single Front

€260 ST-RX820-R (ISTRX820RBI)
€260 ST-RX820-L (ISTRX820LI)
€215 BL-RX820-L (IBLRX820L)
€240 ST-RX820-LA (ISTRX820LAI)

€70 BR-RX820 Front (IBRRX820F6RF)
€65 BR-RX820 Rear (IBRRX820RDRF)

€235 FC-RX820-2, FC-RX820-1

[harblhat]

Are there no cranks shorter than 170? Even 105 is now offered down to 160.

[ooo]

it is the same as previous generation GRX:
FC-RX810-11 175, 172.5, 170
FC-RX820-12 175, 172.5, 170

oem cranks may be avaible in 165:
FC-RX600-11 175, 172.5, 170, 165
FC-RX610-12 ???

[pdlpsher1]

All of the latest 12-speed groups have 160 available. It's weird the GRX doesn't get the same treatement. Not that it matters for me anyways. I'm already on 155s.

[pdlpsher1]

RD-RX820 for 2x12 with 11-36T or 11-34T
RD-RX822-GS for 1x12 with 10-45T
RD-RX822-SGS for 1x12 with 10-51T

Too bad there's no 11-40 2x option.

[spdntrxi]

RD-RX820 for 2x12 with 11-36T or 11-34T
RD-RX822-GS for 1x12 with 10-45T
RD-RX822-SGS for 1x12 with 10-51T

Too bad there's no 11-40 2x option.

I agree steep gravel sweetspot for mortals.

[pdlpsher1]

Lol. Shimano even has a webpage on short cranks. I guess they believe gravel riding needs longer cranks because rock strikes add excitment to gravel riding.

https://road.shimano.com/us/stories/short-crank-curious

[otnemem]

No Di2, no party. Not to mention their lagging on the MTB front, that should put the braintrust on notice.

[RDY]

RD-RX820 for 2x12 with 11-36T or 11-34T
RD-RX822-GS for 1x12 with 10-45T
RD-RX822-SGS for 1x12 with 10-51T

Too bad there's no 11-40 2x option.

As they're doing a mid length (GS) derailleur, I'd guess it'll work fine in 2x with a road front derailleur, as current GRX does. There was some expectation that there'd just be a short and long (i.e. SGS) option, neither of which might work with between road & MTB cassette sizes and 2x.

[Ritxis]

No Di2, no party. Not to mention their lagging on the MTB front, that should put the braintrust on notice.

Presumably there will also be a Di2 version.....I suppose Shimano will launch with the 2 versions

Perhaps the mechanical version would be more advanced in terms of design/production/distribution so that the list of parts is "known before... when some brand already "filtered" bicycle specifications with it...also that when removing the mechanical 105, the differences in certain parts (mechanical/hydraulic internal mechanism) of the shifters are the same

It would be a serious mistake by Shimano not to release the Di2 version or to do it much later than the mechanical version.