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

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RDY
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by RDY

Ritxis wrote:
Mon Mar 20, 2023 12:20 pm
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.
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.
There never seemed to be much GRX Di2 in the OEM market, vs loads of mechanical. I suspect that may remain the case, and why the mechanical parts list has been leaked early. I don't think Shimano will do 105Di2 pricing level GRXDi2, so brands will just buy in Rival AXS for the lower end, and they'll get a better deal if they go all AXS for the electronic gravel equipped bikes than mixing and matching.

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ultimobici
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by ultimobici

RDY wrote:
Mon Mar 20, 2023 12:38 pm
Ritxis wrote:
Mon Mar 20, 2023 12:20 pm
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.
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.
There never seemed to be much GRX Di2 in the OEM market, vs loads of mechanical. I suspect that may remain the case, and why the mechanical parts list has been leaked early. I don't think Shimano will do 105Di2 pricing level GRXDi2, so brands will just buy in Rival AXS for the lower end, and they'll get a better deal if they go all AXS for the electronic gravel equipped bikes than mixing and matching.
Di2 take up on gravel was a fraction of mechanical. I suspect Shimano may stick with one level of Di2 GRX, leaving anyone looking to save cash to use 105.

thirdsun
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by thirdsun

harblhat wrote:
Mon Mar 20, 2023 12:12 am
Are there no cranks shorter than 170? Even 105 is now offered down to 160.
Yeah, really weird decision: Most smaller people benefit significantly from shorter cranks. This is enough of an issue for me that I wouldn't even consider a GRX equipped bike and rather opt for SRAM's XPLR range.
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ultimobici
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by ultimobici

thirdsun wrote:
Wed Mar 22, 2023 8:02 pm
harblhat wrote:
Mon Mar 20, 2023 12:12 am
Are there no cranks shorter than 170? Even 105 is now offered down to 160.
Yeah, really weird decision: Most smaller people benefit significantly from shorter cranks. This is enough of an issue for me that I wouldn't even consider a GRX equipped bike and rather opt for SRAM's XPLR range.
Shimano have been making 165mm GRX cranks since day 1. Why not wait until they actually announce the real product codes rather than writing them off on the say so of an internet forum post?

maurice1
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by maurice1

ultimobici wrote:
Wed Mar 22, 2023 8:39 pm
thirdsun wrote:
Wed Mar 22, 2023 8:02 pm
harblhat wrote:
Mon Mar 20, 2023 12:12 am
Are there no cranks shorter than 170? Even 105 is now offered down to 160.
Yeah, really weird decision: Most smaller people benefit significantly from shorter cranks. This is enough of an issue for me that I wouldn't even consider a GRX equipped bike and rather opt for SRAM's XPLR range.
Shimano have been making 165mm GRX cranks since day 1. Why not wait until they actually announce the real product codes rather than writing them off on the say so of an internet forum post?
I think that's wrong.
GRX 800 cranks only came in 170, 172.5 and 175
GRX 600 had a 165 option for some reason? I really don't understand that decision. Wish they'd just drop 172.5 for 165

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ultimobici
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by ultimobici

maurice1 wrote:
Wed Mar 22, 2023 8:52 pm
I think that's wrong.
GRX 800 cranks only came in 170, 172.5 and 175
GRX 600 had a 165 option for some reason? I really don't understand that decision. Wish they'd just drop 172.5 for 165
GRX 600 is available in 165 in both 1x & 2X 11 speed variants as well as 2x 10 speed. They have been since day 1. Why drop the most popular length in favour of 165. That makes no sense at all.

thirdsun
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by thirdsun

ultimobici wrote:
Wed Mar 22, 2023 8:39 pm
thirdsun wrote:
Wed Mar 22, 2023 8:02 pm
harblhat wrote:
Mon Mar 20, 2023 12:12 am
Are there no cranks shorter than 170? Even 105 is now offered down to 160.
Yeah, really weird decision: Most smaller people benefit significantly from shorter cranks. This is enough of an issue for me that I wouldn't even consider a GRX equipped bike and rather opt for SRAM's XPLR range.
Shimano have been making 165mm GRX cranks since day 1. Why not wait until they actually announce the real product codes rather than writing them off on the say so of an internet forum post?
Like @ultimobici said: Not on the GRX 800 level. I don't like the idea of having to replace my GRX Di2 group with a lesser, heavier crank set. Also, the 4iiii Precision 3 powermeter I'm using only comes as GRX 810 crank and therefor only in 170 mm and up.

It's a poor decision by Shimano.
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ultimobici
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by ultimobici

thirdsun wrote:
Wed Mar 22, 2023 9:05 pm
Like @ultimobici said: Not on the GRX 800 level. I don't like the idea of having to replace my GRX Di2 group with a lesser, heavier crank set. Also, the 4iiii Precision 3 powermeter I'm using only comes as GRX 810 crank and therefor only in 170 mm and up.

It's a poor decision by Shimano.
You do realise that you're criticising a product offering that is almost 5 years old? It was also Shimano's first foray into gravel specific parts, so likely they were hedging their bets and only offered it in the 600 series.

Ultegra & Dura Ace were offered in 165mm when R9100, R8000 & R7000 were launched. Now they have extended down to 160mm with R8100 & R7100. My money woud be on a larger range of shorter armed cranks when GRX12 is launched.

Worst comes to the worst, you could laway look at Praxis. They seem to offer GRX specific versions of all their cranks in 165mm.

maurice1
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by maurice1

ultimobici wrote:
Wed Mar 22, 2023 9:01 pm
maurice1 wrote:
Wed Mar 22, 2023 8:52 pm
I think that's wrong.
GRX 800 cranks only came in 170, 172.5 and 175
GRX 600 had a 165 option for some reason? I really don't understand that decision. Wish they'd just drop 172.5 for 165
GRX 600 is available in 165 in both 1x & 2X 11 speed variants as well as 2x 10 speed. They have been since day 1. Why drop the most popular length in favour of 165. That makes no sense at all.


I think 172.5 just comes as default for most bikes because someone felt like it. Most of us don't really think twice about it but if it never existed I'm sure we'd all be fine on either 170 or 175 without noticing. If they really want to not have too many production lines I would much prefer increments of 5.

And I certainly think more GRX 800 customers would want 165 than GRX 600 customers. It's a common criticism

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pdlpsher1
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by pdlpsher1

I ditched my GRX 800 170mm cranks with left side only Stages for a P2M G-X PM on 155mm Rotor carbon arms. The G-X takes the stock GRX chainrings. Forget spending money on a new crank for only a 5mm change. If you're gonna go short, do a meaningful change, at a minimum of 10mm. Otherwise the effects of the shorter crank on fit is gonna be barely noticeable. Even a 15mm change wasn't that dramatic of a difference for me at all. My wife went from 170mm to 145mm, and that was a meaningful and welcomed change for her (with an inseam of 28").

thirdsun
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by thirdsun

pdlpsher1 wrote:
Wed Mar 22, 2023 10:04 pm
I ditched my GRX 800 170mm cranks with left side only Stages for a P2M G-X PM on 155mm Rotor carbon arms. The G-X takes the stock GRX chainrings. Forget spending money on a new crank for only a 5mm change. If you're gonna go short, do a meaningful change, at a minimum of 10mm. Otherwise the effects of the shorter crank on fit is gonna be barely noticeable. Even a 15mm change wasn't that dramatic of a difference for me at all. My wife went from 170mm to 145mm, and that was a meaningful and welcomed change for her (with an inseam of 28").
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.
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maurice1
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by maurice1

pdlpsher1 wrote:
Wed Mar 22, 2023 10:04 pm
I ditched my GRX 800 170mm cranks with left side only Stages for a P2M G-X PM on 155mm Rotor carbon arms. The G-X takes the stock GRX chainrings. Forget spending money on a new crank for only a 5mm change. If you're gonna go short, do a meaningful change, at a minimum of 10mm. Otherwise the effects of the shorter crank on fit is gonna be barely noticeable. Even a 15mm change wasn't that dramatic of a difference for me at all. My wife went from 170mm to 145mm, and that was a meaningful and welcomed change for her (with an inseam of 28").
Has your gearing changed? I don't want to do the math myself but I vaguely remember 150mm 46-30 was equivalent to a 55-43 or something.
I know I'd be begging for a 28-14 myself

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pdlpsher1
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by pdlpsher1

maurice1 wrote:
Wed Mar 22, 2023 10:28 pm
pdlpsher1 wrote:
Wed Mar 22, 2023 10:04 pm
I ditched my GRX 800 170mm cranks with left side only Stages for a P2M G-X PM on 155mm Rotor carbon arms. The G-X takes the stock GRX chainrings. Forget spending money on a new crank for only a 5mm change. If you're gonna go short, do a meaningful change, at a minimum of 10mm. Otherwise the effects of the shorter crank on fit is gonna be barely noticeable. Even a 15mm change wasn't that dramatic of a difference for me at all. My wife went from 170mm to 145mm, and that was a meaningful and welcomed change for her (with an inseam of 28").
Has your gearing changed? I don't want to do the math myself but I vaguely remember 150mm 46-30 was equivalent to a 55-43 or something.
I know I'd be begging for a 28-14 myself
I was fearing that I'd need lower gearing to compesate for a lack of torque. But I was pleasantly surprised that on the same climb that I do all of the time, I'm on the same gear or one higher. I attribute this to an increase in efficiency to produce a higher torque, because with the shorter cranks my power phase is now longer and the reduction in the pedaling circle allowed my legs to maximize torque production. I felt no need to increase my gearing range, even when I do some steep climbs that I max out on the low gearing (both before and after the crank chang). On those steep climbs where I'm gear limited, at the very least I've maintained the same power. And since I'm pedaling at the same cadence due to being gear limited, the math suggests that my torque output must be higher, but the higher torque is easier to produce with shorter cranks so it doesn't feel it's 'harder' to push the pedals. I hope this makes sense.

warthog101
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by warthog101

https://road.cc/content/feature/pogacar ... olo-285041

All of his bikes use a 172.5mm crank length.

https://dmcx.com/2022/06/14/jonas-vinge ... ng%20shoes.

Jonas Vingegaard rides with 172.5mm crank length

https://dmcx.com/2022/03/13/primoz-rogl ... D%20pedals.

Primož uses 172.5mm crank length

https://dmcx.com/2020/03/24/egan-bernal ... bike-size/

He uses a 170mm Crank arms length

https://dmcx.com/2022/07/12/geraint-tho ... L%20pedals.

Thomas uses a 175mm crankset arm’s length

https://www.firstcomponents.com/bike-cr ... 20involved.

Chris Froome at 1.86m in height uses 175mm cranks

https://dmcx.com/2022/05/02/vincenzo-ni ... s%20length.

Vincenzo Nibali rides with 172.5mm crank arm’s length


Meh, I expect Shimano is selling what works.

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pdlpsher1
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by pdlpsher1

thirdsun wrote:
Wed Mar 22, 2023 10:17 pm
pdlpsher1 wrote:
Wed Mar 22, 2023 10:04 pm
I ditched my GRX 800 170mm cranks with left side only Stages for a P2M G-X PM on 155mm Rotor carbon arms. The G-X takes the stock GRX chainrings. Forget spending money on a new crank for only a 5mm change. If you're gonna go short, do a meaningful change, at a minimum of 10mm. Otherwise the effects of the shorter crank on fit is gonna be barely noticeable. Even a 15mm change wasn't that dramatic of a difference for me at all. My wife went from 170mm to 145mm, and that was a meaningful and welcomed change for her (with an inseam of 28").
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.

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