10 speed derailleur on 9 speed cassette

[DJR]

http://sheldonbrown.com/searchResults.html?cx=partner-pub-1229949690989515%3A1174459614&cof=FORID%3A10&ie=UTF-8&q=compatibility+9+speed+10+speed&sa=Search&siteurl=www.sheldonbrown.com%2F&ref=www.google.co.za%2Furl%3Fsa%3Dt%26rct%3Dj%26q%3D%26esrc%3Ds%26source%3Dweb%26cd%3D1%26sqi%3D2%26ved%3D0ahUKEwjx97mR7-LLAhXJ1hQKHd4kA-8QFggaMAA%26url%3Dhttp%253A%252F%252Fwww.sheldonbrown.com%252F%26usg%3DAFQjCNHNAeyyOJ52wNFXvgFQfGMpSFMrqg%26bvm%3Dbv.117868183%2Cd.bGg&ss=12062j6391382j30

 

Here's the shortcut

[Goosebay]

You can use a sram shifter with a shimano 10spd der and 9spd cassette.  You will need to put a shim in.  Do a search.  Most recommend 6mm, I found a 10mm to be best (X7 shifter, XT 10spd der, 12-34 cassette).  Sharp and crisp - best of both worlds. 

 

The shimano pull is not quite 1:1 - therefore the need for the shim

 

Edit - this is for a mountain bike only (for clarity)

[Frana17]

Thanks so much for all the reply's much appreciated! I helped him today and managed to fix his old derailleur completely turns out it was only the cage that was bent.

[droo]

No amount of tweaking will make it work - despite what a few people have said here. The pull ratios are different. The end.

 

Glad to hear you got it sorted though.