Ultegra RX road clutch RD for 2x11 and 2x10

Especially for light weight issues concerning cyclocross / touring bikes & parts.

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FIJIGabe
Posts: 1700
Joined: Tue Sep 11, 2012 6:07 pm
Location: The Lone Star State

by FIJIGabe

Very nice. It looks very similar to the XT M8050 rear derailleur.
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by Weenie


emotive
Posts: 119
Joined: Tue Nov 01, 2016 10:40 am
Location: Melbourne, Australia

by emotive

I have just removed my Dura-Ace 9100 RD and installed the RX-800 to eliminate chain slap.

The shifting is not quite as crisp as the DA, but as good as the Ultegra 6800 SS on my road bike. I can live with that, plus, I have an 11-34 going onto the off-road wheels for lower gearing. Fun times!

boots2000
Posts: 1499
Joined: Mon Oct 15, 2007 9:28 pm

by boots2000

I recently set up an RX805 DI2 rear derailleur with a 34/50 crankset and an 11-40 cassette.
It shifted great with clutch off- But with clutch on, it lagged adn did not want to climb the cogset.
I discovered that it worked better with the cluth tension dialed down- near bottom of recommended range. 3nm.

boots2000
Posts: 1499
Joined: Mon Oct 15, 2007 9:28 pm

by boots2000

Another thing that I noticed is that the clutch derailleur is more sensitive to battery life.
I was adjusting with a low battery and it stopped working while the clutch was engaged- Charged it back up and all is well.
Seemed like it used up the battery more quikcly but I may have not truly had a full charge (new bike)- I have charged it fully now and I will watch it.

boots2000 wrote:
Fri Oct 12, 2018 5:19 pm
I recently set up an RX805 DI2 rear derailleur with a 34/50 crankset and an 11-40 cassette.
It shifted great with clutch off- But with clutch on, it lagged adn did not want to climb the cogset.
I discovered that it worked better with the cluth tension dialed down- near bottom of recommended range. 3nm.

spdntrxi
Posts: 2352
Joined: Sat Jul 20, 2013 6:11 pm

by spdntrxi

boots2000 wrote:
Thu Oct 18, 2018 6:37 pm
Another thing that I noticed is that the clutch derailleur is more sensitive to battery life.
I was adjusting with a low battery and it stopped working while the clutch was engaged- Charged it back up and all is well.
Seemed like it used up the battery more quikcly but I may have not truly had a full charge (new bike)- I have charged it fully now and I will watch it.

boots2000 wrote:
Fri Oct 12, 2018 5:19 pm
I recently set up an RX805 DI2 rear derailleur with a 34/50 crankset and an 11-40 cassette.
It shifted great with clutch off- But with clutch on, it lagged adn did not want to climb the cogset.
I discovered that it worked better with the cluth tension dialed down- near bottom of recommended range. 3nm.
that switch is fully mechanical... so I have my doubts in that thoery

j0dan
Posts: 5
Joined: Fri Sep 21, 2018 5:47 pm

by j0dan

I finished my setup with a 50/34 crank and a RX805 with 11-40t cassette. In the end I did need the RoadLink DM to get good shifting performance. If you *don't* have a RoadLink you will need a longer b-screw.

EDIT: I had an every so slightly bent hanger causing issues that the RoadLink mitigated. With a new hanger even the original hanger works great.
Last edited by j0dan on Fri Nov 16, 2018 5:58 pm, edited 1 time in total.

boots2000
Posts: 1499
Joined: Mon Oct 15, 2007 9:28 pm

by boots2000

I know But the motor has to work harder to overocme the clutch.
spdntrxi wrote:
Fri Oct 19, 2018 3:28 am
boots2000 wrote:
Thu Oct 18, 2018 6:37 pm
Another thing that I noticed is that the clutch derailleur is more sensitive to battery life.
I was adjusting with a low battery and it stopped working while the clutch was engaged- Charged it back up and all is well.
Seemed like it used up the battery more quikcly but I may have not truly had a full charge (new bike)- I have charged it fully now and I will watch it.

boots2000 wrote:
Fri Oct 12, 2018 5:19 pm
I recently set up an RX805 DI2 rear derailleur with a 34/50 crankset and an 11-40 cassette.
It shifted great with clutch off- But with clutch on, it lagged adn did not want to climb the cogset.
I discovered that it worked better with the cluth tension dialed down- near bottom of recommended range. 3nm.
that switch is fully mechanical... so I have my doubts in that thoery

pdlpsher1
Posts: 1909
Joined: Thu Jul 19, 2012 6:09 pm
Location: CO

by pdlpsher1

j0dan wrote:I finished my setup with a 50/34 crank and a RX805 with 11-40t cassette. In the end I did need the RoadLink DM to get good shifting performance. If you *don't* have a RoadLink you will need a longer b-screw.
Do you have the GS or the regular version? With the GS you shouldn’t need the RoadLink.


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romanmoser
Posts: 166
Joined: Sun May 06, 2018 8:30 pm

by romanmoser

the RX is only in the longer version ...

j0dan
Posts: 5
Joined: Fri Sep 21, 2018 5:47 pm

by j0dan

pdlpsher1 wrote:
Wed Nov 07, 2018 10:54 am
j0dan wrote:I finished my setup with a 50/34 crank and a RX805 with 11-40t cassette. In the end I did need the RoadLink DM to get good shifting performance. If you *don't* have a RoadLink you will need a longer b-screw.
Do you have the GS or the regular version? With the GS you shouldn’t need the RoadLink.


Sent from my iPhone using Tapatalk
You're right. I had a bent derailleur hanger causing my problems and they appeared to go away with the RoadLink.

wpccrunner
in the industry
Posts: 402
Joined: Fri Dec 07, 2012 8:34 pm
Location: North Carolina

by wpccrunner

haven't seen it mentioned yet, but I am curious on the derailleur housing. I've seen in the past the new non-clutched shadow road derailleurs sometimes require a stiffer cable housing to work properly. I am looking into getting this RD for my CX bike (2019 trek crockett) , but it runs full length housing. Will regular housing work fine with the clutched RD?

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Calnago
Posts: 7324
Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

You should be fine. The separate piece of housing that is included with the newer rear derailleurs is very flexible (not stiffer as you mention above) and the steel is wound like a brake housing cable versus a standard derailleur cable housing. This makes it easier to route a short tight radius bend from the end of the chainstay exit port to the attachment point on the rear derailleur. But with your Crocket, the housing runs along and outside of the chainstay so you should be able to get a nice easy loop all the way to the derailleur. In other words, you’ll be fine. With a larger loop, you don’t want the derailleur housing to be too flexible back there or it would be flopping all around which is not what you want next to the rotating sprockets, chain and spokes.
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BobbyAamand
Posts: 2
Joined: Tue Nov 20, 2018 7:45 pm
Location: Copenhagen, Denmark

by BobbyAamand

Hi I'm new here. So I don't know wether I should start a new thread or not. Sorry if this is OT
So I have a 2018 Caadx Tiagra and after reading this thread I started wondering about buying a RX800 derailleur to use with the 4700 shifters and a 10sp cassette. Can anyone actually confirm that this will work?

I have searched around different forums quite a bit and am starting to get confused.

Also I have a FD-CX70 front mech and I am wondering if that will mate with the 4700 brifters?

ooo
Posts: 708
Joined: Sat May 21, 2016 12:59 pm

by ooo

ST-4700-R should be compatible with RD-RX800
ST-4700-L should not be compatible with FD-CX70
ST-4703-L should be compatible with FD-CX70-F-D and FD-CX70-B-D
ST-4703-L should not compatible with FD-CX70-F-T and FD-CX70-B-T
'

BobbyAamand
Posts: 2
Joined: Tue Nov 20, 2018 7:45 pm
Location: Copenhagen, Denmark

by BobbyAamand

Thanks ooo. I will get the RD then as I will want to touring on gravel and a bit of single track next summer.

Btw found another thread about the CX-70. Apparently it comes on the Cannondale Slate paired with 11sp brifters.

by Weenie


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