Ultegra RX road clutch RD for 2x11 and 2x10

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

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cycleboyco
Posts: 74
Joined: Sat Jan 30, 2010 1:19 am

by cycleboyco

FIJIGabe wrote:
Fri Jul 26, 2019 10:03 pm
Do you have access to the PC1 connector? You might want to plug it into the RD and the battery to see if there's anything wrong with the devices.
Actually turned out to just need a B-screw adjustment and all is well. Appreciate your suggestion.

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FIJIGabe
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Location: The Lone Star State

by FIJIGabe

Glad you were able to figure it out.

by Weenie


thefuzzycow
Posts: 95
Joined: Sun Aug 19, 2018 8:52 am

by thefuzzycow

MichaelB wrote:
Fri Jun 28, 2019 12:31 am
Hex wrote:
Thu Jun 27, 2019 12:24 pm
Is there an issue with the RX800 (mechanical) RD as well?

Would the tension need to be dialed down in order to shift properly?...
Haven't had to do any adjustments on mine and it shiifts fine with 36/46 & 10-42 cassette
A little thread revival here... It became a topic of discussion on the Cervelo Aspero thread in regards to the RX805 working with a 2x and 11-36 and up cassette.

I'm running 36/46 with an 11/34. I got the rx805 when it came out for my build and it's still working great. Trying to find out what my limits are with it. I'm building up my new Aspero and thought about throwing an 11-36 on the back but the limit says 11-34.

Michael, you say you're running a 36/46 with an 10-42 and having zero problems? Add a road link/goatlink?

Confused how that's working.
"moo"
Cervelo Aspero
Specialized Epic
Quintana Roo pr5

thefuzzycow
Posts: 95
Joined: Sun Aug 19, 2018 8:52 am

by thefuzzycow

Thread bump! 🤪
"moo"
Cervelo Aspero
Specialized Epic
Quintana Roo pr5

fourfa
Posts: 59
Joined: Mon Sep 26, 2011 3:04 am

by fourfa

I have RX800 and the stated 11-34 limit is typical conservative Shimano - 11-36 works like OEM. Obviously when you space out the big cog with the B-screw, you gain a little clearance at the small cogs - but shifting performance is terrific for me. I also don't bother bringing the B-screw down when I switch to my 11-32 road wheelset, and shifting is still great. I'm very happy with this setup.

thefuzzycow
Posts: 95
Joined: Sun Aug 19, 2018 8:52 am

by thefuzzycow

fourfa wrote:
Tue Apr 28, 2020 8:24 pm
I have RX800 and the stated 11-34 limit is typical conservative Shimano - 11-36 works like OEM. Obviously when you space out the big cog with the B-screw, you gain a little clearance at the small cogs - but shifting performance is terrific for me. I also don't bother bringing the B-screw down when I switch to my 11-32 road wheelset, and shifting is still great. I'm very happy with this setup.
Awesome!! Thanks fourfa

So if I put an 11-36 on my Aspero, will I have to adjust the B screw at all? Or wil it be pretty close to perfect as it is now?
"moo"
Cervelo Aspero
Specialized Epic
Quintana Roo pr5

fourfa
Posts: 59
Joined: Mon Sep 26, 2011 3:04 am

by fourfa

You'll probably need to turn the B screw inward a little.

MichaelB
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Joined: Tue Apr 22, 2008 4:31 am

by MichaelB

thefuzzycow wrote:
Sat Apr 25, 2020 4:03 am
...

Michael, you say you're running a 36/46 with an 10-42 and having zero problems? Add a road link/goatlink?

Confused how that's working.
Was on a Cannondale Slate frame, and if anything, it didn't like chnaging down from the 42T quickly. Did it, but wasn't happy, and really indicating that it's the upper limit. No roadlink etc fitted, direct onto frame.

40T however (Sunrace cassette) is fine, and now have a GT Xizang 9r (2012 Ti version) frame running 28/34 front and 11-40 rear, and all good.

Cheers

Michael

Theologian
Posts: 57
Joined: Sat Jun 23, 2018 3:34 am

by Theologian

Okay, so Rx-800 shifts up to 42t on the back. How about the total teeth difference though? The max specification is officially 16+23=39t in a 2x setup, has anyone tried to stretch the total teeth difference to 43 or beyond? How is the chain tension for setup that's over 39t for total t differential? I'm thinking of using 50/32t in the front (that's right, not the usual compact 50/34t) and 11-34t on the back for a total of 41 t differential, I know people have used 40t on the back, but with 28/34 in the front, the total t differential is only 35t, that's well within specs for chain tension. I use di2 synchro-shift, so I'm not worried about cross chaining. Thanks.

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pdlpsher1
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Location: CO

by pdlpsher1

I helped a friend setup her RX800 with 11-40 cassette and 50/34 chainrings. Di2 prevents 34-11 and 34-13. I left the chain at full length so she can run 50-40 without damaging anything. And on 34-15 the chain is still not too long. I can still shorten the chain a bit without compromising anything. Shifting is perfect.

Theologian
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Joined: Sat Jun 23, 2018 3:34 am

by Theologian

That's great, thanks. Then I'm to go ahead and get the 32t front chainring. I'll report back how everything works.

fourfa
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Joined: Mon Sep 26, 2011 3:04 am

by fourfa

my 46/30 crank (16t) and 11-36 cassette (25t) adds up to 41t total. I've got tension in 30-11 and the RD spring is slightly more extended than I'd prefer in 46-36; but even with my shortish 420mm chainstays, it backpedals just fine, shifts fine, still has some extension in the cage but any more and the tension starts to get too high IMHO. Big-big is a lot more important to me than small-small, as it seems more likely to end up there accidentally when bonked (small-small makes more noise so I'm more likely to wake up from a stupor when I hear it). I use 113 links on the chain. Also I tend to leave the RX800 clutch on at all times, I think that helps with the low tension situations.

If I had Di2 to lock out 30-11 I'd insert another link

Theologian
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Joined: Sat Jun 23, 2018 3:34 am

by Theologian

That's valuable info, wow. Thank you for sharing.

thefuzzycow
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Joined: Sun Aug 19, 2018 8:52 am

by thefuzzycow

I'm just wanting to go 46/36 with an 11-36 cassette. After reading everybody else's experiences, in trying to wrap my head around if my set up would be easier or more difficult... 🤔
"moo"
Cervelo Aspero
Specialized Epic
Quintana Roo pr5

by Weenie


MichaelB
Posts: 733
Joined: Tue Apr 22, 2008 4:31 am

by MichaelB

thefuzzycow wrote:
Tue May 05, 2020 10:57 pm
I'm just wanting to go 46/36 with an 11-36 cassette. After reading everybody else's experiences, in trying to wrap my head around if my set up would be easier or more difficult... 🤔
More difficult than what ?

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