Dura-Ace STI + GRX RD = poor indexing
04-12-21, 09:20 PM
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Dura-Ace STI + GRX RD = poor indexing
Hi all,
This is my first thread on this forum, and I need to start with an issue:
My bike is 2019 Cannondale CAADX, which I have modified to some extent... regarding the drivetrain, I have:
Dura-Ace 9100 mechanical STIs (new)
GRX rd-rx812 dear derailleur (new)
XT 11-40 cassette (new)
Dura-Ace hg901 chain (110 links, about 100km ridden)
40t OPI spidering in the front (about 500km ridden).
Shifting cable is dura ace grade, new.
The issue is that I am unable to get proper indexing from this setup. There is some noize either on third smallest cog (15t) or 3rd biggest cog (31t). All other cogs are perfect. The issue is worse with clutch on and after shifting to 40t cog and back. Changing tension with derailleur built-in barrel adjuster even for 1-2 notches causes some noise at either of cogs.
With clutch off I can adjust it with almost no noize on 31t cog and perfect 15t cog, but if I turn barrel adjuster even 1 notch to eliminate this small noise at 31t, or switch on clutch and shift to 40t cog and back, I got awful chain noize at 3rd largest cog.
To solve this issue I have tried the following:
1) Changed cassette from SLX 11-40 to XT 11-40, same story
2) Had my derailleur hander aligned by respectable LBC with pro tool, very little effect (at least I can adjust indexing somewhat correct with clutch off)
3) Lube cables with Phil Tenacious Oil, no effect
Also, limit screws, b screw all set properly. Cable tension seems ok. No sharp bends at cable housings.
chain also seems to be of a right length (422mm chainstays, 40t/40t max cog rear/front, quick link, 110 links)
Derailleur is rated to clear 40t cog at minimum...
What else should I check? This issue drives me mad! I came from 10speed, hadn’t any issues... is this just how 11 speed indexing difficult to adjust?
Hub is DT Swiss 350, rear axle is 10mm RWS thru bolt, proper 1.85mm spacer for cassette is in place, so no issues here.
Also, with 11-32 cassette = no issues
What else I could check to solve this issue?
Maybe change cable from DA grade to optislick one?
This is my first thread on this forum, and I need to start with an issue:
My bike is 2019 Cannondale CAADX, which I have modified to some extent... regarding the drivetrain, I have:
Dura-Ace 9100 mechanical STIs (new)
GRX rd-rx812 dear derailleur (new)
XT 11-40 cassette (new)
Dura-Ace hg901 chain (110 links, about 100km ridden)
40t OPI spidering in the front (about 500km ridden).
Shifting cable is dura ace grade, new.
The issue is that I am unable to get proper indexing from this setup. There is some noize either on third smallest cog (15t) or 3rd biggest cog (31t). All other cogs are perfect. The issue is worse with clutch on and after shifting to 40t cog and back. Changing tension with derailleur built-in barrel adjuster even for 1-2 notches causes some noise at either of cogs.
With clutch off I can adjust it with almost no noize on 31t cog and perfect 15t cog, but if I turn barrel adjuster even 1 notch to eliminate this small noise at 31t, or switch on clutch and shift to 40t cog and back, I got awful chain noize at 3rd largest cog.
To solve this issue I have tried the following:
1) Changed cassette from SLX 11-40 to XT 11-40, same story
2) Had my derailleur hander aligned by respectable LBC with pro tool, very little effect (at least I can adjust indexing somewhat correct with clutch off)
3) Lube cables with Phil Tenacious Oil, no effect
Also, limit screws, b screw all set properly. Cable tension seems ok. No sharp bends at cable housings.
chain also seems to be of a right length (422mm chainstays, 40t/40t max cog rear/front, quick link, 110 links)
Derailleur is rated to clear 40t cog at minimum...
What else should I check? This issue drives me mad! I came from 10speed, hadn’t any issues... is this just how 11 speed indexing difficult to adjust?
Hub is DT Swiss 350, rear axle is 10mm RWS thru bolt, proper 1.85mm spacer for cassette is in place, so no issues here.
Also, with 11-32 cassette = no issues
What else I could check to solve this issue?
Maybe change cable from DA grade to optislick one?
Last edited by bosozoku; 04-13-21 at 05:00 AM. Reason: Additional info
04-12-21, 11:16 PM
#2
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11-speed index shifting is no less reliable/accurate than 10-speed, and is no more difficult to adjust. I doubt a new cable is going to solve the issue (it could, but isn’t the cable you’d be replacing new, also?).
Perphaps, “zero” all the adjustment, reinstall the RD, the cable, and then follow the procedure for adjustment as described int he Dealer Manual for the RD...to include adjusting the “retention spring,” aka the clutch.
Perphaps, “zero” all the adjustment, reinstall the RD, the cable, and then follow the procedure for adjustment as described int he Dealer Manual for the RD...to include adjusting the “retention spring,” aka the clutch.
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04-12-21, 11:30 PM
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I checked on compatibility. Found this. https://bike.shimano.com/en-US/infor...ad-compon.html . Compatibility is not a problem.
I have found that chain length, B-screw adjustment, and hanger alignment are very important on 1x systems with super wide-range cassettes. Follow instructions carefully; faking the chain length on these is not an option. I haven't done one in a while, so I can't give you specifics. And a side effect of those huge climbing cogs is that they magnify the effect of any small hanger misalignment, or misalignment of the derailleur cage. So double-check. And I found that SRAM was fussier than Shimano.
I have found that chain length, B-screw adjustment, and hanger alignment are very important on 1x systems with super wide-range cassettes. Follow instructions carefully; faking the chain length on these is not an option. I haven't done one in a while, so I can't give you specifics. And a side effect of those huge climbing cogs is that they magnify the effect of any small hanger misalignment, or misalignment of the derailleur cage. So double-check. And I found that SRAM was fussier than Shimano.
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04-13-21, 03:04 AM
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Thanks guys for your suggestions!
What I might try next:
- Increase chain length by 2 links
- Increase B gap from 8mm at the moment to 10-12mm
- Change cable for Opticlick one, because now I have Dura Ace installed with its polymer coating already starts to peeling off.
Will report afterward!
What I might try next:
- Increase chain length by 2 links
- Increase B gap from 8mm at the moment to 10-12mm
- Change cable for Opticlick one, because now I have Dura Ace installed with its polymer coating already starts to peeling off.
Will report afterward!
04-13-21, 04:49 AM
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A couple of thoughts on the various items you mention bosozoku .
Before you do any of those things, I strongly recommend you zero out all of the adjustments (screw all the barrel adjusters in) and ensure your limit screws are properly set. Good luck!
- Chain: By my calculation, using the specs you offered, your chain should actually be 54" (108 links). I don't think chain length is the issue. Slightly long is better than slightly short. (There are several online chain calculators, I'd recommend doing your own calculation, just to be sure.)
- Cables; Replacing the polymer coated DA cable with Optislick is a downgrade according to Shimano. Also, the "fuzzy" look you see where the cable is exposed is normal, and according to numerous mechanics will not affect shifting. Your cable MIGHT have a slight kink somewhere, if it is not perfectly straight from the shifter to the RD (I don't mean without curves as it runs through the housing), this could be your problem.
- B-screw: 8-10 mm should be about right for the chain to shift from the 35T up to the 40T. Also, unless I have been mistaken all these years, the B-screw won't affect the "index." I'd recommend not messing with this until you ensure you've got the correct chain length and a straight shift cable.
Before you do any of those things, I strongly recommend you zero out all of the adjustments (screw all the barrel adjusters in) and ensure your limit screws are properly set. Good luck!
04-13-21, 04:56 AM
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A couple of thoughts on the various items you mention bosozoku .
Before you do any of those things, I strongly recommend you zero out all of the adjustments (screw all the barrel adjusters in) and ensure your limit screws are properly set. Good luck!
- Chain: By my calculation, using the specs you offered, your chain should actually be 54" (108 links). I don't think chain length is the issue. Slightly long is better than slightly short. (There are several online chain calculators, I'd recommend doing your own calculation, just to be sure.)
- Cables; Replacing the polymer coated DA cable with Optislick is a downgrade according to Shimano. Also, the "fuzzy" look you see where the cable is exposed is normal, and according to numerous mechanics will not affect shifting. Your cable MIGHT have a slight kink somewhere, if it is not perfectly straight from the shifter to the RD (I don't mean without curves as it runs through the housing), this could be your problem.
- B-screw: 8-10 mm should be about right for the chain to shift from the 35T up to the 40T. Also, unless I have been mistaken all these years, the B-screw won't affect the "index." I'd recommend not messing with this until you ensure you've got the correct chain length and a straight shift cable.
Before you do any of those things, I strongly recommend you zero out all of the adjustments (screw all the barrel adjusters in) and ensure your limit screws are properly set. Good luck!
By eye H and L limits seem to be set up properly, but even smallest misalignment could cause poor indexing... I will play with limit screws.
If nothing helps I will try to throw in SRAM 11-36 cassette (hope 40t minimum from derailleur's spec won't be a problem...)
Before I went to 11 speed I was using GRX 10 speed with 11-36 XT cassette and had no issues whatsoever!
Last edited by bosozoku; 04-13-21 at 05:03 AM.
07-19-22, 04:48 PM
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Check to see if the cable is threaded through the rear derailleur the correct way. (I've done this wrong more times than I care to admit, and the symptoms are similar to what you describe.)
from https://manualzz.com/doc/53871739/sh...ealer-s-manual
from https://manualzz.com/doc/53871739/sh...ealer-s-manual
Last edited by Polaris OBark; 07-19-22 at 04:57 PM.
07-21-22, 01:41 AM
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My Ibis MX Hakka came with
Rear Derailleur Shimano GRX RX812 Shadow Plus
Cassette Shimano XT 11-46
praxis 40T
Shift Levers Shimano GRX R810
It shifted great.
I moved over the
Rear Derailleur Shimano GRX RX812 Shadow Plus
Cassette Shimano XT 11-46
from the Ibis to convert my Giant revolt adv to 1x
and used the Giant
It shifted great
At least for me I have found GRX RX812 ( meant for 1x ) works great
Some companies use GRX RX810 for 1x even though that derailleur was designed for 2x. I have not ridden this combo.
The only thing I can say is when shifting from the biggest sprocket 46 ( 1st gear ) to 2nd gear is a big physical gap and it helps if pedal slowly when shifting.
Rear Derailleur Shimano GRX RX812 Shadow Plus
Cassette Shimano XT 11-46
praxis 40T
Shift Levers Shimano GRX R810
It shifted great.
I moved over the
Rear Derailleur Shimano GRX RX812 Shadow Plus
Cassette Shimano XT 11-46
from the Ibis to convert my Giant revolt adv to 1x
and used the Giant
- Shifters Shimano GRX RX-600
It shifted great
At least for me I have found GRX RX812 ( meant for 1x ) works great
Some companies use GRX RX810 for 1x even though that derailleur was designed for 2x. I have not ridden this combo.
The only thing I can say is when shifting from the biggest sprocket 46 ( 1st gear ) to 2nd gear is a big physical gap and it helps if pedal slowly when shifting.
