11 Speed derailleur 9 speed Cassette

[roundisland]

Hi is it possible to use an 11 speed derailleur with a 9 speed cassette?

 

[raleighnut]

Hi is it possible to use an 11 speed derailleur with a 9 speed cassette?

Yep with friction shifters it'll be fine.

 

[DCBassman]

It will probably work with a 9-speed indexed shifter too. That is, after all, what determines the movement of the derailleur.

 

[winjim]

It will probably work with a 9-speed indexed shifter too. That is, after all, what determines the movement of the derailleur.

ITYFIABMCTT

 

[Racing roadkill]

Pull ratios will be different, so the answer is no, not with indexed shifters, possibly with friction shifters, but that takes a bit of practice.

 

[Ming the Merciless]

You’ll be fine with friction

 

[winjim]

This article explains it quite well. You need to consider cable pull (shifters), pull ratio (mech) and sprocket pitch (cassette). Basically for it to work, pull multiplied by ratio needs to equal pitch. The movement is not linear across the range, this is compensated for at the shifter or at the cassette, depending on manufacturer. You've also got chain compatibility to think about. The short answer is no, it won't.

http://blog.artscyclery.com/science...ce-behind-the-magic-drivetrain-compatibility/

 

[davidphilips]

7,8,9 and 10 speed (shimano) rear derailleurs are all the same ratio so if you need a rear derailleur it should be easy to pick up a used one for little money on Ebay.

 

[winjim]

7,8,9 and 10 speed (shimano) rear derailleurs are all the same ratio so if you need a rear derailleur it should be easy to pick up a used one for little money on Ebay.

Road or mountain? And what about the shifters? 10sp road mech with 11sp shifters and 9sp cassette puts you 1.4mm out at either end of the range. Which might be fine but I expect it would be a bit rattly.

 

[DCBassman]

I'd forgotten the ratio change at 11...
D'oh...

 

[davidphilips]

Road or mountain? And what about the shifters? 10sp road mech with 11sp shifters and 9sp cassette puts you 1.4mm out at either end of the range. Which might be fine but I expect it would be a bit rattly.

11 speed are different ratio.

 

[winjim]

11 speed are different ratio.

Shifters so we're talking cable pull, not ratio. And since we don't know what shifters the op has, it seems plausible that they may have 11sp. And if you're going to buy a used mech as you suggest, you might need to factor in shifters as well, by which time you might as well replace the lot and do it properly.

Still don't know if it's road or mountain either.

 

[Racing roadkill]

7,8,9 and 10 speed (shimano) rear derailleurs are all the same ratio so if you need a rear derailleur it should be easy to pick up a used one for little money on Ebay.

The 10 speed 4700 Tiagra RD is the same ratio as the 11 speeds.

 

[roundisland]

Sounds like a 9 speed derailleur will be the easiest option . I just didn’t want to buy one if it wasn’t necessary. Thanks for all the replies, most helpful.

 

[Ajax Bay]

Yes I’m changing bars , shifters, chain and derailleur. Hope that’s going to go without problems.

The OP said this on another thread about putting an 11 speed cassette on a hub that had had a 9 speed cassette on. These items (not the bars!) are called 'x' speed for a reason. There is some compatibility, sometimes, but you're wasting your time asking single item questions. Say what you've got. Say what you want to achieve, and the advice you'll get will be more useful, imo, (but with less 'chat' ).