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

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TomSte
Posts: 48
Joined: Tue Jun 25, 2019 9:18 am

by TomSte

Any idea when the new GRX will be available?

by Weenie


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Hexsense
Posts: 3270
Joined: Wed Dec 30, 2015 12:41 am
Location: USA

by Hexsense

This entire post is about crank length. Feel free to skip to the next one if you are tired with this off topic.
warthog101 wrote:
Thu Mar 23, 2023 4:13 am
Disagree I am missing your point.
People at 162.5 cm in height would be a very small proportion of people buying a groupset.
Each generation is getting taller not shorter.
Current global average male height in 2023 is 175 cm.
Current global average female height in 2023 is 162 cm.
And that's average. Meaning, there 's approximately half of the population shorter than the average. If you see a lot of people vastly taller than average, there'd be another equal group of people shorter than average. So that average is average.

Currently, most shorter than average people don't cycle because they don't feel good on a bike. So the market size them out and reinforce the notion that average people who buy bikes are taller than average global population.

PS. I'm in camp that'd like to see crank length expand down into 155mm range. I'm 169cm riding 165mm crank on my road, gravel and mtb and I don't mind using crank that don't match the groupset so the current length offering is fine for me. But I don't look down at other people's struggle.

pdlpsher1 wrote:
Wed Mar 22, 2023 11:28 pm
thirdsun wrote:
Wed Mar 22, 2023 10:17 pm
As a small rider (165 cm / 75 cm inseam) I'm used to 165 mm cranks and noticed the 170 mm GRX cranks my Canyon Grail came with immediately. In my opinion those 5 mm are very noticeable. However the effect might be more pronounced on the edges of the size spectrum.
I'm also on the shorter side, but with a slightly above average leg length (170mm tall, 80cm inseam). I decided against spending money for only a 5mm change. So I went from 170mm to 155mm, which was noticeable but not as dramatic as some claimed to be. When I ride my MTB which came with 175mm cranks, I do notice it due to the 175mm being too long for me. You are probably right that the effect will be more pronounced on the edges of the size spectrum. Going from 170mm to 175mm will be more dramatic than going from 155mm to 160mm, for a person of my height.
Cranklength perception is not linear. If it's too long, even 2.5mm too long is perceivable vs just right length that is 2.5mm shorter, if you experience both.
But once you are in the range of "not too long" you can barely feel 5mm change in length. The problem though is a lot of short rider never experience crank length that feels right. So they ride whatever come with the bike thinking it's normal.

I'm not so sure why do we try hard to be at the edge of longest crank that is not too long though. Let say most 170cm rider can ride 165mm crank optimally and some can takes 170mm as well. Since some 170cm rider can ride 170mm optimally, The bike size for 170cm rider is fitted with 170mm crank and if you can't tolerate this length's discomfort then it's your loss???

Hexsense
Posts: 3270
Joined: Wed Dec 30, 2015 12:41 am
Location: USA

by Hexsense

In the topic of Grx.
otnemem wrote:
Mon Mar 20, 2023 8:39 am
No Di2, no party. Not to mention their lagging on the MTB front, that should put the braintrust on notice.
1x and di2 in the current form doesn't make a lot of sense. You still need central battery and wire. But then you only get a little better rd shifting. No front derailleur shifting and auto trim benefit since there's no front derailleur.
ooo wrote:
Sun Mar 19, 2023 9:51 am
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
I assume RD-RX820 to be slant parallogram but RD-RX822-GS and RD-RX822-SGS are horizontal parallogram design?
ultimobici wrote:
Wed Mar 22, 2023 9:23 pm
Worst comes to the worst, you could laway look at Praxis. They seem to offer GRX specific versions of all their cranks in 165mm.
Do we have a good list of cranks that offer good chainline and 2x chainring size for gravel ?
Praxis cranks and rings,
Power2max gravel power meter cranks,
Rotor cranks and rings,
Gearoop chainrings on Sram cranks (the 44/28 and 46/30 are nice),
what else.

warthog101
Posts: 872
Joined: Wed Sep 25, 2013 10:05 am

by warthog101

Hexsense wrote:
Tue May 02, 2023 3:48 pm

warthog101 wrote:
Thu Mar 23, 2023 4:13 am
Disagree I am missing your point.
People at 162.5 cm in height would be a very small proportion of people buying a groupset.
Each generation is getting taller not shorter.
Current global average male height in 2023 is 175 cm.
Current global average female height in 2023 is 162 cm.
And that's average. Meaning, there 's approximately half of the population shorter than the average. If you see a lot of people vastly taller than average, there'd be another equal group of people shorter than average. So that average is average.

Currently, most shorter than average people don't cycle because they don't feel good on a bike. So the market size them out and reinforce the notion that average people who buy bikes are taller than average global population.

PS. I'm in camp that'd like to see crank length expand down into 155mm range. I'm 169cm riding 165mm crank on my road, gravel and mtb and I don't mind using crank that don't match the groupset so the current length offering is fine for me. But I don't look down at other people's struggle.
I accept that women are shorter and a higher proportion may need shorter cranks.
There is however less women choosing to cycle. Many reasons for that I expect. Safety around traffic would be a huge reason. I don't see the lack of a suitable crank length on road groupsets discouraging a huge proportion.


A big guess to say many don't cycle due to not being comfortable on a bike and that is solely down to crank length.

NickB
Posts: 66
Joined: Sun May 23, 2021 11:13 am

by NickB

As a long legged 100kg rider in a very hilly area can I have 177.5 please?
Maybe some slick engineering option for adjustment, an eccentric in crank so two sizes available?
Must be a ££ nightmare for the bean counters trying to accomodate all, but then wasn't that part of the real reason for compact frames if we are honest? Must be a solution besides niche products and in gravel a few gramms is not going to hurt.

ooo
Posts: 1590
Joined: Sat May 21, 2016 12:59 pm

by ooo

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)
'

DrimeOser
Posts: 105
Joined: Wed Sep 01, 2021 1:35 pm

by DrimeOser

So, it looks like the next GRX will be compatible with the 12-MTB cassettes just as the current one is based on the 11-speed ones.

I would still prefer a dedicated gravel cassette like XPLR but likely we'll not see that.

maurice1
Posts: 143
Joined: Mon Dec 19, 2022 12:51 pm
Location: Jura

by maurice1

11-30, 11-33, 11-36, 11-39, 11-42, 10-45, 10-48, 10-51. Is that too much to ask for shimano? :(

SRAM is increasingly becoming the customer-friendly company

robertbb
Posts: 2179
Joined: Thu Jul 23, 2009 3:35 am

by robertbb

DrimeOser wrote:
Wed May 24, 2023 2:57 pm
So, it looks like the next GRX will be compatible with the 12-MTB cassettes just as the current one is based on the 11-speed ones.

I would still prefer a dedicated gravel cassette like XPLR but likely we'll not see that.
+1

I want this too - what makes you think we won't see it though?

DrimeOser
Posts: 105
Joined: Wed Sep 01, 2021 1:35 pm

by DrimeOser

I have no insights to offer, just for the last GRX I thought it was a lazy move from Shimano taking the cassette from their already aged MTB group and marketing it as, 'Hey our gravel group can be paired with the MTB groups.' Running it, I was pretty dissapointed by the limited range, since shifting and braking were top notch.
Also, I don't get why they don't have a GRX on Dura Ace level. There definitely is a marked for that, see the Red XPLR.

robertbb
Posts: 2179
Joined: Thu Jul 23, 2009 3:35 am

by robertbb

I remain hopeful that Shimano will deliver a non-series, HG-based, 11-42 cassette to compete with SRAM's XPLR. It's a clear gap in their lineup today. Not to mention eKar already bests them both so Shimano is really lagging there.

If I am not mistaken, SRAM is eventually going to be releasing an Apex AXS XPLR cassette that is standard HG and starts with an 11t. This might work nicely on a Shimano 1x setup too.

maurice1
Posts: 143
Joined: Mon Dec 19, 2022 12:51 pm
Location: Jura

by maurice1

robertbb wrote:
Thu May 25, 2023 1:06 am
DrimeOser wrote:
Wed May 24, 2023 2:57 pm
So, it looks like the next GRX will be compatible with the 12-MTB cassettes just as the current one is based on the 11-speed ones.

I would still prefer a dedicated gravel cassette like XPLR but likely we'll not see that.
+1

I want this too - what makes you think we won't see it though?
In what way are the 11-40 to 11-46 not dedicated gravel? They were originally meant for 2x MTB but they work perfectly for gravel

satanas
Posts: 315
Joined: Sat Jul 04, 2020 5:45 pm

by satanas

The problem with the proposed drivetrains is that one can have either reasonably wide range (though not wide enough) *or* close ratios (though not in the midrange). Unlike some, I actually liked the 11 speed HG-800 (11-34) cassette, and IME the best thing about it is close-ish ratios everywhere, 11-13 excepted; there are no other nasty gaps. The 12 speed road cassettes go 21-24-27/28 versus 21-23-25-27 for HG-800, IMO much more disruptive.

I'd say the chance of any new 12 speed cassettes appearing from Shimano are zero, but maybe there will be more third party options, like Ingrid's 11-44 and Sunshine's 11-42 & 11-46. Hopefully somebody like S-Ride will make a suitable 2X RD compatible with the GRX 12 levers.

Just why Shimano would try to force the road-12-only freehub bodies down everyone's throats is beyond me; they should abandon that idea immediately or they will sell fewer wheels. :-(

As for the 11 speed 11-40/42/46 Shimano cassettes, the 11-40 is just about okay (except for 21-24), 11-42 is considerably worse (esp. 24-28), and 11-46 also has a huge gap into low gear (37-46). They may be fine if you have no interest in maintaining a reasonably even cadence; given that's usually impossible when mountsin biking, gaps aren't so much of an issue there.


CampagYOLO
Posts: 705
Joined: Thu May 06, 2021 3:58 pm

by CampagYOLO

A 10-45 cassette is much better in terms of range and also suggests potential cross compatibility with the mountain bike equipment.

However, would this necessitate a move to Microspline?

by Weenie


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