11 speed upgrade, indexing problem

djcozzer

I've upgraded my bike to 11 speed Shimano from 10spd Shimano. Have upgraded shifters,cassette but kept crank set and rear mech. LBS says this should work okay, but indexing proving difficult. Setting up on the big ring and smallest ring on the cassette, I can get it set to drop only 2 gears before it chatters and wont go any further. Resetting from that gear only allows it to drop 2 gears again but wont go back up. Cable tensions are good. Do I need to change the rear mech/crank set or is there something else. Any useful advice gratefully received.

Ta

Colin

trailflow

Do I need to change the rear mech

Yes. 10 spd mechs are not compatible with 11 speed. Cable pull and geometry are different. You're LBS is talking rubbish.

You're old crank will work fine.

djcozzer

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19711807#p19711807]trailflow[/url] wrote:

Do I need to change the rear mech

Yes. 10 spd mechs are not compatible with 11 speed. Cable pull and geometry are different. You're LBS is talking rubbish.

You're old crank will work fine.

Thanks mate

svetty

Have you changed the cables too - excessive cable friction won't help indexing

kwozzymodo

I am not sure. You will definitely need the 11-speed shifter. It's the shifter that determines the amount of cable travel for the rear derailleur to shift up or down the cassette. You would need to change the upper and lower limits of the derailleur, and possibly the B screw setting depending on how the cage sits against the cassette. Other than that, the spring tension and movement of the existing 10-speed derailleur should work with 11 speed.

There's a fair amount of info on various wensites regarding 10/11 speed compatability and, for example, Leonard Zinn suggests that you can use a Shimano 10 speed derailleur with Shimano 11 speed shifters.

southdownswolf

10 speed rear is not compatible with 11 speed shifters.

have a look at the old thread and the links provided...

viewtopic.php?f=40004&t=13015074

StillGoing

One area where SRAM has an edge then. Their rear 10 speed mech is adaptable with 11 speed shifters. Strange that Shimano don't have similar thinking?

kwozzymodo

Don't SRAM have the same pull ratios across their road and mtb transmissions as well?

StillGoing

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19714930#p19714930]kwozzymodo[/url] wrote:

Don't SRAM have the same pull ratios across their road and mtb transmissions as well?

No idea; I don't have anything to do with MTBs. But the road groupsets are downwards compatible so to upgrade from a 10 speed set up, the user only needs to change the shifters, chain and cassette. 10 speed derailleurs (front and back) work with 11 speed shifters, although a Yaw 22 front makes front shifting smoother even with 10 speed.