Will DuraAce shifters operate an Ultegra rear derailleur?

Father Faff

Will 11sp Dura Ace 9000 shifters operate Ultegra rear derailleurs ok? I'm thinking of changing an 11-28 casette to an Ultegra 11-32 but I think I will need to remove the DuraAce rear derailleur and fit an Ultegra long-cage rear derailleur.

ride_whenever

they should work the 6800 ones

Father Faff

Thanks ride-whenever, I was thinking the new 6800. Any idea who could confirm this?

ugo.santalucia

I would try without replacing the derailleur first. The cage length is unrelated to the sprockets size... it might work with the DA RD you've got

DiscoBoy

Father Faff wrote:

Thanks ride-whenever, I was thinking the new 6800. Any idea who could confirm this?

All 11 speed shimano components are completely interchangeable.

Stevie_gee

ugo.santalucia wrote:

The cage length is unrelated to the sprockets size...

bigger sprockets need longer chains, in order to be able to maintain correct tension when using harder gears, you need a RD with a longer cage

ugo.santalucia

Stevie_gee wrote:

ugo.santalucia wrote:

The cage length is unrelated to the sprockets size...

bigger sprockets need longer chains, in order to be able to maintain correct tension when using harder gears, you need a RD with a longer cage

Not necessarily... the problem with big cassettes is whether the jockey wheels clear the cassette rather than the cage length. Modern derailleurs can cope with a rather large range and if you don't use a 53 x32 or a 39 x 11 or similarly silly gears, you don't normally need long cage for a double

markhewitt1978

ugo.santalucia wrote:

I would try without replacing the derailleur first. The cage length is unrelated to the sprockets size... it might work with the DA RD you've got

Good advice, OP is going to have to replace the cassette anyway (obviously) so it doesn't hurt to try this first.

Matthewfalle

Shifters will work fine - you can swap basically any year shifters with any mechs (numbers of gears will obviously count on the shifter) but there will be brake pull ratio issues.

Stevie_gee

ugo.santalucia wrote:

Stevie_gee wrote:

ugo.santalucia wrote:

The cage length is unrelated to the sprockets size...

bigger sprockets need longer chains, in order to be able to maintain correct tension when using harder gears, you need a RD with a longer cage

Not necessarily... the problem with big cassettes is whether the jockey wheels clear the cassette rather than the cage length. Modern derailleurs can cope with a rather large range and if you don't use a 53 x32 or a 39 x 11 or similarly silly gears, you don't normally need long cage for a double

i must admit i've never tinkered with such setups, and I thought the difference was only in the gap between the jockey wheels, rather than between sprocket and top jockey wheel?

so what is the usual application of a long cage RD ?

ugo.santalucia

Stevie_gee wrote:

ugo.santalucia wrote:

Stevie_gee wrote:

ugo.santalucia wrote:

The cage length is unrelated to the sprockets size...

bigger sprockets need longer chains, in order to be able to maintain correct tension when using harder gears, you need a RD with a longer cage

Not necessarily... the problem with big cassettes is whether the jockey wheels clear the cassette rather than the cage length. Modern derailleurs can cope with a rather large range and if you don't use a 53 x32 or a 39 x 11 or similarly silly gears, you don't normally need long cage for a double

i must admit i've never tinkered with such setups, and I thought the difference was only in the gap between the jockey wheels, rather than between sprocket and top jockey wheel?

so what is the usual application of a long cage RD ?

Triple chainsets and any case where your setup exceeds the derailleur capacity. But in the latter case, you have to assess whether you actually need it.
If you avoid using the extreme gears (big-big and small small) you might not need it at all.

It works like this:

Determine Maximum Chainring Difference by subracting the number of teeth in the smallest chainring from the number of teeth in the largest chainring

Determine Maximum Cassette Cog Difference by subtracting the number of teeth on the smallest cassette cog from the number of teeth on the largest cassette cog

Determine Total Drivetrain Capacity by adding Maximum Chainring Difference to the Maximum Cassette Cog Difference

In the case of Shimano, only MTB derailleurs in theory are able to be paired with a 32 T sprocket

SS - Short Cage Road Double - Maximum Cassette Cog is 27 and Total Capacity is 29

GS - Medium Cage MTB/Road Triple - Maximum Cassette Cog is 34(MTB)/27(Road) and Total Capacity is 33(MTB)/37(Road)

SGS - Long MTB - Maximum Cassette Cog is 34 and Total Capacity is 45

mister p

The maximum rear sprocket size for an RD-9000 Dura Ace rear mech is 28T with a total difference of 33T. Running an 11-32 cassette with a 50/34 chainset give a total difference of 37T. So I would say it is very likely you are going to need an Ultegra 6800 GS rear mech as this is rated to 32T top and a maximum difference of 37T.

twgh

Has anyone successfully run an 11-32 with a DA9000 RD? I want one for the alps / dolomites next summer.

Pokerface

I currently run DuraAce shifters with 6770 rear mechs on all bikes - no problems there.

On all my own bikes, I use a special (Berner) cage which allows me to run 11-32 cassettes.

On my girlfriend's bike, I just put a long cage onto a 6770 mech and she is running 11-32 no problem (but with a 50-34 chainring).

There are 2 things you can go to help run a 32 cassette - one is to either get a longer B-screw, or turn the exiting one around and screw it in backwards - either of these will help move the mech further away from the cassette in the biggest gear.

I also usually swap out the top jockey wheel from an 11T to a 10T to give extra room.


Although the 6870 Di2 has a long-cage option as standard, you CAN just buy the long cage parts and put it on the 6770 mech if you prefer to run 10-speed.