Ultegra r8000 with an 11-40 cassette?

Anyone tried this? Internet says it is workable.  If not anyone done 11-36?

What size front chain rings?

50-34.

I know the mech isn’t rated to take more than a 34 but I’ve seen internet videos…

you could always buy a roadlink-type thing

What dat?

RoadLink

dis ^

Ta.  It’s an option cheers.

11-36 is fine with a medium cage mech and 34/50 in my experience.

Hanger length is usually key, which is where the roadlink comes in. You could probably make 11-40 work one way or another.

Oh, and there are much cheaper ways of experimenting than a road link. e.g. https://www.ebay.co.uk/itm/Bicycle-Rear-Derailleur-Hanger-Extension-Bike-Frame-Gear-Tail-Hook-Extend-UK-CNC/232681711515?var=532169841005

R8000 needs a Goatlink 10 doesn’t it?

Yep, I have done this and it works fine on my bike with 48-32 up front and on my wife’s bike running 34-50.  Didn’t have to do anything special to the derailleur.

Now that you can get hydraulic disc brakes for road/cross bikes, using that and an 11-40 cassette opens the bike up to lots of offload riding

John_key 34/50 and 11/40. Short or medium cage please?

Not going to be short surely!

Thanks all. That’s really helpful.

Running an R 8000 set up. 34 46 at the front with an 11 42 at the back by using the direct mount roadlink. Shifting is perfect. No issues whatsoever. I would recommend it to anyone.

Chain wrap doesn’t exactly look ideal with the link. Wonder if there is any impact on drivetrain life.

@john_key – what is the part number of the cassette that your wife uses on her 50-34 setup, and do you use a goatlink or similar, to get it to work?

To handle chain length and wrap it around those big cogs , if running 50/34 front and 11-40 (11sp) at the back , then a Road Link (or chinese copy) coupled to Deore RD-M591-SGS is a perfect fix , don’t worry that it’s 9sp or MTB, it works with 11sp Ultegra shifters and 10sp 105 shifters ,and changes faultlessly in every front to back combination, big to big and small to small, notwithstanding the naysayers about chainlines, I used Ultegra RD but found it was too ‘compact’, to handle the big rise and fall consistently, plus the huge amount of chain needed .PS, Sunrace cassettes 11-40 in 10 and 11sp versions.

@jamesco yeah I’m doing 34/50 11-40 with 105 SGS and Roadlink but am interested in the extra capacity of the R8000 derailleur as I have one on another boik.

I find it’s useful to read the spec sheets , then bin them and get the bike up on a stand where you can tinker about with different set ups and combinations before taking them out on the road or in the woods to promptly fall flat on your face as everything locks up and tips you off !

I’ve done 11-36 with 46/33. just about.

It will all come down to your mech hanger and how much B screw you have to play with

This^^…but if you exert too much B screw to get below the bigger (40T) sprockets you can lose chain wrap and shift shape of some derailleurs.I agree 36T is easily doable though.

What’s this a 36 or 40 on the rear of a road bike ?  Oh my days. :-)

For cyclists of a certain age and/or with health issues, then it’s a cheaper and purer fix than going e-bike, please don’t get all high-brow about cycling and getting out in the fresh air.

I’ve got a clutch R8000 mech on one bike with 30/44 and and 11-36 cassette and the b-screw is barely halfway in. I’d put good money on it taking a 40 or 42 no problem.

Didnt know a 9 speed shimano MTB mech would work with an 11 speed shimano road shifter

Yup that deore mech works perfectly. Plenty of cage for winding chain, super spring strength for keeping it tight and lots of side to side movement to cover the cassette spread plus the mech itself has long levers to keep it under the sprockets, and it works direct like a road mech. I have to admit that I have tried all kinds of bodges, mixes and fixes mostly to satisfy my own curiosity as to what will and will not work, it’s often surprising what can be done ‘off spec’, or as they call it in my industry ‘off licence’!  I quite enjoy the perplexed looks from ‘bike snobs’ as they peruse my mix and match set ups.

@LS, sure you are right, it only needs to be tried………….

Excellent, thanks, Jamesco. Will give it a go..

Well damn it all to hell. Just sold a 9 speed deore mech and would have loved to try that combo just for the hell of it

It was a medium cage rear mech and a XT 11-40 cassette.  No problems at all and no modifications needs.

Sifting works fine.

I do like the look of the new clutch road derailliuers Shimano has some out with too

Just a quick note to thank you all for your input.

R8000 medium cafe derailleur and CS-M8000 11-40 cassette working just fine on the workstand (once I remembered to install the spacer onto the freehub, before the cassette)
Will be heading out for a gentle shakedown ride, one evening, this week, to be sure it’s tuned correctly.

Managed a long enough ride to assess correct operation of the gears, before a split in the front tyre forced an early shower.
Gear changing was lovely and smooth, and I now feel like I could ride up walls (although the hills along the Jurassic coast may prove me wrong)

This is exactly what the new GRX mech is designed for.

R8000 medium cafe derailleur and CS-M8000 11-40 cassette working just fine

Is that a single ring up front or a double?

I’m fitting an RX800 mech and 11-40 next week, hoping it’s all going to work but this thread sounds positive. Will add a post once it’s tested

R8000 medium cafe derailleur and CS-M8000 11-40 cassette working just fine

Is that a single ring up front or a double?

Double 50-34

This is exactly what the new GRX mech is designed for.

Quite possibly true, but I already had the r8000 mech, and was following this thread before the GRX range was announced, so had gone and bought the cassette.

Would be interesting to hear if folks (@jameso, probably) have been investigate the options that GRX presents

Ok – feedback time.
Just got home from our week long ride, starting at Plymouth and pretty much following the coast back home to Crawley (hopping onto and off of the Isle of Wight), covering 320 miles.
The r8000 mech, paired with the CS-M8000 11-40 cassette worked perfectly, never missing a beat, always shifting cleanly, and shrugging off what, at times, was biblical weather.
To sum it up…

• If you’re super-fit, you don’t need this
• If you’re moderately fit, then it will get you up some stuff that may have previously beaten you
• If you’re not very fit, it’ll get you further up the hills that you managed before
• Some hills just seem impossible ‘Salcombe Hill Rd‘ and ‘The hill that shall not be named, out of Branscombe‘

…I’m glad I had it.