Ultegra RX road clutch RD for 2x11 and 2x10

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

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ooo
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by ooo

RD-RX800 - mechanical RD officially compatible with 2x11 sti, unofficially compatible with 2x10 tiagra 4700
RD-RX805 - di2 RD, official compatible with road di2 FD
both compatible with cassette range 11-28 to 11-34

https://www.youtube.com/results?search_ ... egra+rx%22
As road bike riding diversifies towards multiple road surfaces such as adventure and off-road riding Shimano introduces Ultegra RX, an off-shoot of Ultegra, with a rear clutch derailleur (RD-RX800/RX805) for mechanical and Di2 drivetrains.

Riders have been pushing the limits of what a road bike is capable of riding for many years, evolving the sport from racing to encompass greater adventure. In recent years we’ve seen a broader definition of what a drop handlebar bike can look like; road wheels followed that by accommodating wider tyres. Now in a natural evolutionary step it’s time for drivetrains to evolve too.

The new RX800/805 rear derailleurs shares many characteristics with the Ultegra R8000/R8050 derailleur, such as precise accurate shifting and SHIMANO SHADOW RD derailleur positioning, but with the added chain stabilizing switch (known as SHIMANO SHADOW RD+ technology) to control the drivetrain over rough/uneven ground or off-road surfaces. Much like Shimano’s MTB derailleurs the On/Off switch can be found next to the upper pulley. When activated the rear derailleur pivot takes a firm hold to reduce excessive movement, noise and general ‘chain chatter’.

The RX800/805 rear derailleurs are compatible with road dual control levers (mechanical or Di2) and will accommodate cassettes with low gears from 28T to 34T, making them a very necessary addition for all types of adventure and off-road riding including cyclocross and compact styles with 46T-36T up to 50T-34T chainrings.

Consumers can expect the new components to be available in stores from mid-June 2018 onwards.
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Last edited by ooo on Wed Jul 04, 2018 5:46 pm, edited 3 times in total.
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wheelsONfire
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by wheelsONfire

I heard clutch RD's have more drag?
With that said, i am still interested in the RX.

I drilled a new hole at my 6870 RD for tension spring to have more tension.
Now the RD easily accept a Sram PG-1170, 11-36
I think it works better now, than what it did with WT Roadlink.

Truth be told, chain jumped quite alot throwing chain inwards.
But that was probably due to the chainline using 6800 crank.
I changed the 6800 crank to Easton EC90SL, Kent Eriksens custom Spider and Wickwerks 44/34 CX chainring combo.
Now i have close to 47mm chainline instead of 43.5mm.
Shifting is flawless!
No more jumping chain.

I also lowered my FD using Sugino MT-OX adapter, allowing FD to be positioned in the correct height from the chainrings.
https://www.suginoltd.co.jp/us/products ... Parts.html
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Ax Lightness Vial EVO D
Paduano Racing Fidia
Open *UP*
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Multebear
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by Multebear

This is very good news. Finally some competion for Srams force/rival 1 groupsets. Only thing bothering me is max 11-36 cassette. I want to ride it with 11-42 like srams offerings. Can it be done?

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

by ooo

this is for double, not 1x group, max cassette is 11-34
to use 11-42 (and loose 2x compatibility) you have to change cage (like it was on 10sp shadow+ mtb derailleurs)
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Multebear
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by Multebear

Does that fit ultegra rear mech? I mean I have no problem running 1x11 if 11-42 is possible.

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

by ooo

we have to see it first... I have send you pm with some more details

I think It will be possible to fit other cage, but it may need extra steps/diy
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motorapido
Posts: 264
Joined: Fri Jul 30, 2010 7:08 pm

by motorapido

Shimano tend to keep parts common to reduce cost, so based on their MTB clutch mechs it probably uses the same one way roller clutch bearing locking spring and main spindle, so it should be possible to mount any MTB cage directly to it, for the MTB bits from Deore to XT these clutch parts are all the same, only XTR differs slightly. The MTB mechs can easily be stripped down and cage changed with only a set of allen keys and a cross head screwdriver. I wouldn't expect the road version to be any more complicated. They certainly look identical to the MTB parts from the photos.

The only thing i found when i made my clutched ultegra mech a few years ago is that the derailleur pulley centreline to the mounting face of the cage on to the B knuckle is about 1.5mm greater on the road mech to the MTB.
It mean't that i had to add a spacer to get things lined up properly or you couldn't get the largest cog on the cassette.

Ghost234
Posts: 423
Joined: Sun Apr 24, 2011 2:21 am

by Ghost234

I don't really understand why people would not just use the XT RDR. Di2 is fully compatible, and previous generation mech (I assume newer as well) worked perfectly.

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

by ooo

for single chainring setup ultegra rx and xt covers different types of cassettes (11-40..46 and 11-28..34)
for double chainring setup, it was fast from perfect...

mtb di2 rd requires 2 hardware mods to make it work fast on road cassette with single chainring
mtb di2 rd requires 4+ hardware mods to make it work fast on road cassette with double chainring

mtb fd sometimes impossible to mount on road frame because non round seat tube with braze on fd mount
mtb fd limit crankset choice or requires some road crankset mods (i.e. octalink road crank with longer bb axle)

road di2 fd requires software mod to make it work with mtb di2 rd, and this setup will never support synchroshift
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NickJHP
Posts: 106
Joined: Wed Feb 14, 2018 2:22 am

by NickJHP

Multebear wrote:
Wed Apr 04, 2018 6:18 pm
Does that fit ultegra rear mech? I mean I have no problem running 1x11 if 11-42 is possible.
For 1x with road shifters, why not use SRAM instead? They have a 1x road group that comes with an 11-42 cassette (https://www.sram.com/sram/road/family/sram-apex-1), or alternatively all their exact actuation components are compatible, so you can use road shifters and MTB RDs. I have a couple of bikes using Force 22 shifters and X9 MTB RDs, though these are two chainring and not 1x.

ooo
Posts: 570
Joined: Sat May 21, 2016 12:59 pm

by ooo

Shimano catalog weight

info posted 01.04.2018:
RD-RX800-GS 248 g

info posted 14.05.2018:
RD-RX805-GS 280 g

(XTR RD-M9050-GS 290 g)
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Nefarious86
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by Nefarious86

Ghost234 wrote:I don't really understand why people would not just use the XT RDR. Di2 is fully compatible, and previous generation mech (I assume newer as well) worked perfectly.
Can't pair an XTR mech with a road front Derailleur.

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rainerhq
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by rainerhq

Somebody here have inside information, when RX-805 will be available?
Domane
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ultimobici
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by ultimobici

rainerhq wrote:Somebody here have inside information, when RX-805 will be available?
Due in to us later today


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rainerhq
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by rainerhq

us= some shop?
Could you please specify.
Domane
"Nothing compares to the simple pleasure of a bike ride"

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