R8000 Rear Derailleur: A Word to the Wise

[mpemburn]

Skip this thread if you already know enough to follow the directions in the box.
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Okay, for the rest of us who plunge right in and do what our manly sense tells us is right and after-all-I've-done-this-a-million-times-before:

A few months ago, I destroyed my beautiful old Trek. Please don't ask me how. I was able to salvage most of the parts, but the rear mech was shot. It was an Ultegra 6800 long cage, but I'd heard that the new RD-R8000's were the hot thing, so I bought one.

As I say, I had a lot of the old parts, including the cable housings. Being the frugal sort, I kept the housing for the RD. It was the right length, wasn't it?

So, bike's all set up and, after clearing up a problem with hanger alignment (done by LBS), I whizzed off into the countryside, grinning from ear to ear.

Then, one morning, I go out the the barn (where the bike lives) and get set for a ride...except for that flat on the rear. A short time later, I've replaced the tube and I'm set to stick the wheel back on. Following the usual procedure, I place the chain on the small cog and pull up...pull UP...PULL UP!!! but the @#$%!! thing won't pull! After some further fiddling, I was able muscle it in and only got a few dents in my fingers pinching them between cog and chain.

Now, I could pray that I never have another rear flat, but that's not practical. I posted the question on another bike forum (Brand-X, I believe) and got nothing useful. Eventually, I found the answer: the RD R8000 comes with a special cable housing that is more flexible than the standard issue type. It makes shifting easier—and eases the tension on the cage enough to make it possible to get the wheel in and out!

Thus, I leave this warning unto ye: RTFM! I will from now on read the forsaken manual on any advanced bike product because they deserve it. Boy, do they.

 

[fossyant]

So it comes with it's special cable and you didn't use it....

Shimano have done that for years. My 7400 Series came with a really special shifter cable, super fine threads for a down tube shifter, and special outer cables. Fitted it, still looks like new, and works, 30 years later. Anything else, on other bikes with Ultegra level, didn't last.... Magic...

Don't scrimp on cables....👅

 

[mpemburn]

So it comes with it's special cable and you didn't use it....

Shimano have done that for years. My 7400 Series came with a really special shifter cable, super fine threads for a down tube shifter, and special outer cables. Fitted it, still looks like new, and works, 30 years later. Anything else, on other bikes with Ultegra level, didn't last.... Magic...

Don't scrimp on cables....👅

Not the cable, just the housing that goes between the chain stay and the mech.

 

[fossyant]

Not the cable, just the housing that goes between the chain stay and the mech.

I know, but read the distructions.... especially if there are 'extra 'bits'..

 

[fossyant]

Don't get SRAM Eagle 12 speed on MTB's - that is fussy on set up..... works great when done, but if not...

 

[mpemburn]

The thing that has hobbled me is that I cut my teeth on bike setup decades ago with Campagnolo equipment. It was much more forgiving. Comparing a five or six speed “block” with friction shifters to an 11 speed indexed setup is like night and day.

 

[itboffin]

Ultegra R8000 total ball ache

 

[mpemburn]

Ultegra R8000 total ball ache

Have you had other problems with this besides what I've mentioned? {braces self}

 

[itboffin]

Have you had other problems with this besides what I've mentioned? {braces self}

Its just so fussy to setup especially the front, i will give it this once setup its a dream but my what a PITA. I've given up on my Cannondale CAAD12 after weeks of me trying and two LBS totally failing as well, i'm going with not compatible.

 

[wonderloaf]

Its just so fussy to setup especially the front, i will give it this once setup its a dream but my what a PITA. I've given up on my Cannondale CAAD12 after weeks of me trying and two LBS totally failing as well, i'm going with not compatible.

Interesting you say this, I've just transferred the R8000 groupset form my old (broken) frame to a new one and didn't have any problems at all with setting up the FD, actually found it easier than the 6800 on another bike , I've actually had more problems with the RD which I think come down to the internal cable routing being slightly different on the new frame.
My problem with the RD is that I can't get the gear changes to be quite as snappy as on the old frame so I've purchased the 'special' cable as suggested upthread, hopefully this will improve matters!

 

[T4tomo]

There are a few things at work meaning it harder to set up gears on "newer" bikes vs the good old days (see also the mech hanger tool thread)

• more gears, meaning finer tolerances
• internal gear routing, in the old days you ran your outer to get a nice smooth bend, internal routed cables follow suboptimal curves
• shifter units are more complex, so more to go wrong and cables are also sub-optimally routed within them
• less compatibility between brands and group-sets / series within brands

The fact that a RD needs specialist outer cable housing to work properly is really quite something

 

[mpemburn]

Its just so fussy to setup especially the front, i will give it this once setup its a dream but my what a PITA. I've given up on my Cannondale CAAD12 after weeks of me trying and two LBS totally failing as well, i'm going with not compatible.

Ooh—okay. I only have the rear mech since the front was still good after the disaster with the old bike. Good to know.

 

[Bike Tyson]

Sidenote, I use Sora 9 speed rear mech with 4600 shifters (10 speed) as it has same cable pull ratio, I think 4700 rear mech (10 speed) has same cable pull ratio as 11 speed Shimano shifters.

 

[itboffin]

Interesting you say this, I've just transferred the R8000 groupset form my old (broken) frame to a new one and didn't have any problems at all with setting up the FD, actually found it easier than the 6800 on another bike , I've actually had more problems with the RD which I think come down to the internal cable routing being slightly different on the new frame.
My problem with the RD is that I can't get the gear changes to be quite as snappy as on the old frame so I've purchased the 'special' cable as suggested upthread, hopefully this will improve matters!

yep the softer cable is a must

 

[chriswoody]

Don't get SRAM Eagle 12 speed on MTB's - that is fussy on set up..... works great when done, but if not...

Alternatively, fight like mad with a SRAM Rival one derailleur (or any clutched SRAM derailleur) to get the rear wheel in, all the while wondering what that button with a padlock on it does.

Only after several fights do you finally check Google and discover what said padlock button does! Dohh!