Go Back  Bike Forums > Bike Forums > Cyclocross and Gravelbiking (Recreational)
Reload this Page >

Shimano GRX RD 810 on 11-46t cassette, is it possible?

Notices
Cyclocross and Gravelbiking (Recreational) This has to be the most physically intense sport ever invented. It's high speed bicycle racing on a short off road course or riding the off pavement rides on gravel like :The Dirty Kanza". We also have a dedicated Racing forum for the Cyclocross Hard Core Racers.

Shimano GRX RD 810 on 11-46t cassette, is it possible?

Old 01-07-20, 06:59 PM
  #1  
rivfranxco
Junior Member
Thread Starter
 
Join Date: Jan 2020
Location: Philippines
Posts: 5

Bikes: Surly Midnight Special, Surly Straggler, Marin Pinemountain

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Shimano GRX RD 810 on 11-46t cassette, is it possible?

Planning to get the GRX STI 810 along with the RD and would pair it with my existing 11-46T cassette but Shimano stated that the GRX RD only can handle up to 42T cassette. Does anyone have tried this before?
rivfranxco is offline  
Old 01-07-20, 11:26 PM
  #2  
Bryan C. 
nothing to see here
 
Bryan C.'s Avatar
 
Join Date: Sep 2007
Location: Antioch, CA
Posts: 505
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 192 Post(s)
Liked 115 Times in 62 Posts
I can't say for sure, but it probably will be fine. If not, try a wolftooth roadlink. I run a similar one on my MTB with an XT derailleur. It says it fits all the current Shimano road derailleurs and the 810 looks to be the same design.


Wolftooth Roadlink DM.
Bryan C. is offline  
Old 01-08-20, 11:20 PM
  #3  
rivfranxco
Junior Member
Thread Starter
 
Join Date: Jan 2020
Location: Philippines
Posts: 5

Bikes: Surly Midnight Special, Surly Straggler, Marin Pinemountain

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
[QUOTE=Bryan C.;21274987]I can't say for sure, but it probably will be fine. If not, try a wolftooth roadlink. I run a similar one on my MTB with an XT derailleur. It says it fits all the current Shimano road derailleurs and the 810 looks to be the same design.


That's what I'm also thinking. I have an extender like a roadlink. Well, I hope the RD alone is enough just to save weight. Lol. Thanks for the input!
rivfranxco is offline  
Old 01-13-20, 01:08 PM
  #4  
MAGAIVER
Senior Member
 
MAGAIVER's Avatar
 
Join Date: May 2009
Location: Brazil, Londrina PR
Posts: 258

Bikes: Kona Unit, Kona Kahuna, Kona Dew DL, Scott Big Jon, Trek Checkpoint ALR4, KHS Urban Soul, Haro Team Issue, Cernunnos Touro, GT Force Expert Carbon

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Liked 30 Times in 15 Posts
That would be quite a lot for the RD-RX810 , the biggest cog it can handle in the back is a 34. The RD-RX812 will handle an 11-46.
MAGAIVER is offline  
Old 01-14-20, 07:05 PM
  #5  
DarKris
Senior Member
 
DarKris's Avatar
 
Join Date: Dec 2015
Location: Buffalo, NY
Posts: 523

Bikes: Giant Revolt 2 - GRX 1x11 (2020), Giant Toughroad GX 1 - 1x10 (2018), Specialized Hellga - NX 1x12 (2017)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 131 Post(s)
Liked 37 Times in 22 Posts
If you don't care about weight you can get a SLX derailleur and a Wolftooth Tanpan since it fully supports an 11-46. I did this and it also saved me ~$15 but I haven't installed it yet. Once I do I can report back on how well it works.

Last edited by DarKris; 01-14-20 at 07:08 PM.
DarKris is offline  
Old 01-15-20, 12:38 AM
  #6  
redlude97
Senior Member
 
Join Date: Sep 2011
Posts: 4,656
Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
Quoted: 1924 Post(s)
Liked 178 Times in 130 Posts
Originally Posted by MAGAIVER View Post
That would be quite a lot for the RD-RX810 , the biggest cog it can handle in the back is a 34. The RD-RX812 will handle an 11-46.
has anyone confirmed the rd-rx812 works with a 2x11 system yet?
redlude97 is offline  
Old 01-15-20, 04:30 AM
  #7  
DavidfGR
Junior Member
 
DavidfGR's Avatar
 
Join Date: May 2019
Posts: 24

Bikes: Santa Cruz - Stigmata

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Likes: 0
Liked 11 Times in 5 Posts
Originally Posted by MAGAIVER View Post
That would be quite a lot for the RD-RX810 , the biggest cog it can handle in the back is a 34. The RD-RX812 will handle an 11-46.
RD-RX810 will work with 11-40, but this would be max, i tried 11-42 and no go.
DavidfGR is offline  
Likes For DavidfGR:
Old 01-15-20, 06:08 AM
  #8  
MAGAIVER
Senior Member
 
MAGAIVER's Avatar
 
Join Date: May 2009
Location: Brazil, Londrina PR
Posts: 258

Bikes: Kona Unit, Kona Kahuna, Kona Dew DL, Scott Big Jon, Trek Checkpoint ALR4, KHS Urban Soul, Haro Team Issue, Cernunnos Touro, GT Force Expert Carbon

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Liked 30 Times in 15 Posts
Originally Posted by redlude97 View Post
has anyone confirmed the rd-rx812 works with a 2x11 system yet?
I also want to know that, I've seen the 810 used on a 2x setup with an 11-42 cassete but I'm not sure if it will work well.
MAGAIVER is offline  
Old 01-15-20, 02:32 PM
  #9  
katsup
Senior Member
 
katsup's Avatar
 
Join Date: May 2016
Location: Southern California
Posts: 1,271

Bikes: Soma Fog Cutter & Vintage Mountain Bikes

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 428 Post(s)
Liked 250 Times in 145 Posts
Originally Posted by DavidfGR View Post
RD-RX810 will work with 11-40, but this would be max, i tried 11-42 and no go.
Interesting since I got an Ultegra RX800 GS to work with a 11-42T on a 2x11 setup.

katsup is offline  
Old 01-16-20, 12:38 AM
  #10  
rivfranxco
Junior Member
Thread Starter
 
Join Date: Jan 2020
Location: Philippines
Posts: 5

Bikes: Surly Midnight Special, Surly Straggler, Marin Pinemountain

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by DarKris View Post
If you don't care about weight you can get a SLX derailleur and a Wolftooth Tanpan since it fully supports an 11-46. I did this and it also saved me ~$15 but I haven't installed it yet. Once I do I can report back on how well it works.
That was my previous setup for several months. I jüst want to have a "proper" Gravel bike groupset which doesn't mix/matching anymore.
rivfranxco is offline  
Old 01-16-20, 12:45 AM
  #11  
rivfranxco
Junior Member
Thread Starter
 
Join Date: Jan 2020
Location: Philippines
Posts: 5

Bikes: Surly Midnight Special, Surly Straggler, Marin Pinemountain

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by MAGAIVER View Post
That would be quite a lot for the RD-RX810 , the biggest cog it can handle in the back is a 34. The RD-RX812 will handle an 11-46.
I'm talking about the 1X specific RD which Shimano stated that it could handle up to 11-42T. The 2X system just offers up to 34T only.
rivfranxco is offline  
Old 01-17-20, 02:32 AM
  #12  
DavidfGR
Junior Member
 
DavidfGR's Avatar
 
Join Date: May 2019
Posts: 24

Bikes: Santa Cruz - Stigmata

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Likes: 0
Liked 11 Times in 5 Posts
I tried again, this time with my new 2020 Santa Cruz Stigmata, setup with 2x11 Grx Di2, and i can confirm that the rear mech works without problems with 11-42 cassette.
DavidfGR is offline  
Old 01-20-20, 07:09 AM
  #13  
MAGAIVER
Senior Member
 
MAGAIVER's Avatar
 
Join Date: May 2009
Location: Brazil, Londrina PR
Posts: 258

Bikes: Kona Unit, Kona Kahuna, Kona Dew DL, Scott Big Jon, Trek Checkpoint ALR4, KHS Urban Soul, Haro Team Issue, Cernunnos Touro, GT Force Expert Carbon

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Liked 30 Times in 15 Posts
Originally Posted by rivfranxco View Post
I'm talking about the 1X specific RD which Shimano stated that it could handle up to 11-42T. The 2X system just offers up to 34T only.
The 1x RD is the RD-RX812 the RD-RX810 is the 2x version.
MAGAIVER is offline  
Old 01-29-20, 05:13 PM
  #14  
redlude97
Senior Member
 
Join Date: Sep 2011
Posts: 4,656
Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
Quoted: 1924 Post(s)
Liked 178 Times in 130 Posts
Originally Posted by MAGAIVER View Post
I also want to know that, I've seen the 810 used on a 2x setup with an 11-42 cassete but I'm not sure if it will work well.
https://www.cxmagazine.com/shimano-g...10-rx812-rx570

Of course, there’s a difference between what’s recommended and what actually works. Due to a mix-up, our test bike arrived with a GRX 2x RX810 crankset, front derailleur and front and rear shifters, but with a 1x RX812 rear derailleur. It did the job without complaint or issue, and I likely wouldn’t have noticed until I asked Shimano’s Nick Legan why his bike had oversized pulleys while mine did not. Legan diligently followed up, and discovered by mistake I was supplied the wrong derailleur for the 48/31 and 11-34 drivetrain.

In a day I had the proper unit.
I swapped the RX812 derailleur out for the RX810, made a few adjustments and hit the dirt again. The shifting was crisper across the two chain rings as the upper pulley of the RX800 derailleur remained consistently closer to each cog across the cassette. However, I’m thankful for the mixup, as it revealed the effectiveness of the Shimano clutch, as the 1x derailleur handled shifting duties without a chain drop, even though the drivetrain was 9 teeth over the derailleur’s stated capacity.

Similarly, the 2x derailleur can handle duty with larger-than-stated rear cogs with some aggressive B-screw adjustment. We’ve done the same with the RX800 and RX805 derailleurs. Shifting may not be optimal, but it’s certainly possible.

Shimano GRX boasts gearing versatility, but it’s actually even more than the specs indicate.
redlude97 is offline  
Likes For redlude97:
Old 02-01-20, 07:00 PM
  #15  
Lindarets
Junior Member
 
Lindarets's Avatar
 
Join Date: Feb 2020
Location: Albuquerque, NM
Posts: 15

Bikes: J.Guillem Atalaya Gravel, Orient All-Road, & Tomir mountain

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Likes: 0
Liked 11 Times in 4 Posts
Originally Posted by Bryan C. View Post
I can't say for sure, but it probably will be fine. If not, try a wolftooth roadlink. I run a similar one on my MTB with an XT derailleur. It says it fits all the current Shimano road derailleurs and the 810 looks to be the same design.


Wolftooth Roadlink DM.
We've tried them and the RoadLink/RoadLink DM/GoatLink/GoatLink11 don't significantly improve the GRX RD-RX812 performance on an 11-46. Would love to sell you one, but wouldn't feel great about being in the snake oil business.

The 11-46 exceeds Shimano's recommended 31t cage capacity, for what that's worth. But other derailleurs in their line with the same cage length are rated for much more
Lindarets is offline  
Old 02-03-20, 08:21 AM
  #16  
MAGAIVER
Senior Member
 
MAGAIVER's Avatar
 
Join Date: May 2009
Location: Brazil, Londrina PR
Posts: 258

Bikes: Kona Unit, Kona Kahuna, Kona Dew DL, Scott Big Jon, Trek Checkpoint ALR4, KHS Urban Soul, Haro Team Issue, Cernunnos Touro, GT Force Expert Carbon

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Liked 30 Times in 15 Posts
The Evil Chamois Hagar seems to come with GRX 1x with and an 11-46 cassete, at least it has an 11-46 on this review.


https://bikerumor.com/2020/01/23/rev...road-or-trail/


I don't see why it would not work, the RD-RX812 looks a lot like the XT RD-M8000 GS rear derailleur, I would even argue that a Sunrace 11-50 may work. I run full XT8000 with a GS rear derailleur and Sunrace 11-50 on my 29er without any hanger extenders or anything extra and it works flawlessly, I'll try the 11-50 once my GRX 1x group arrives.
MAGAIVER is offline  
Old 02-04-20, 06:46 PM
  #17  
jwill911
Riding is my addiction
 
jwill911's Avatar
 
Join Date: Sep 2006
Location: Alameda, CA
Posts: 181

Bikes: 2017 Orbea Orca,'06 Orbea Opal, 2019 Trek Checkpoint SL6

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Liked 0 Times in 0 Posts
Thanks for the link and quote. I just replaced the Ultegra 50-34 chainset and FD for a GRX 48-31 and FD, on my Checkpoint SL6. And was trying to determine the difference between and correct RD for my 2x setup, the RD-812 or RD-810. This article made it clear so now I'm planning to follow up with the GRX RD-RX810 RD with a 11-40 or 11-42 cassette..
Thanks,
John
jwill911 is offline  
Old 02-12-20, 08:07 PM
  #18  
jwill911
Riding is my addiction
 
jwill911's Avatar
 
Join Date: Sep 2006
Location: Alameda, CA
Posts: 181

Bikes: 2017 Orbea Orca,'06 Orbea Opal, 2019 Trek Checkpoint SL6

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Liked 0 Times in 0 Posts
Originally Posted by DavidfGR View Post
RD-RX810 will work with 11-40, but this would be max, i tried 11-42 and no go.
I want to chime in here and confirm the RD-RX810 works with a 11-40 in a 2x.
Just picked my bike up from my LBS, they were iffy about the 11-40, telling me the Shimano specs state 34 max, but they said it worked easier than they thought it would.
I bought my Trek Checkpoint SL6 with Ultegra group, swapped out the compact 50-34 for a GRX 48-31 (w/ GRX front derailleur). But wanted to go lower so bought the RD810 and 11-40. Now I'm going to need to put some knobbier tires on as traction will be the issue now on steep rocky climbs.
John

Last edited by jwill911; 02-12-20 at 08:10 PM. Reason: typo
jwill911 is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.