Australian Cycling Forums - Bicycles Network Australia

Shimano Ultegra 9 speed shifter with 9 speed cassette ( 12-27 ) and chain but 10 speed Ultegra derailleur.... OK?
or
Shimano Ultegra 9 speed shifter with 9 speed cassette ( 11 - 34 ) and chain but 9 speed XTR derailleur.... OK?

All should be fine. Internal size on 9 & 10 speed chains are the same; & Shimano 9 speed road & MTB have the same pull ratio I believe.

Ta, not worried about the chain... just wasn't 100% sure a 10 speed derailleur would work with 9 speed shifter.
... or that 9 speed Shifter would work with ( old school ) XTR derailleur... the question being do I go 11-34 or 12-27 .

The third page down would indicate that you should be fine:
http://www.shimano.com/publish/content/ ... 0Chart.pdf
ie Shimano 9 speed shifters (Tiagra) will work with 10 speed RD's (5600,6600,7800) with.9 speed cassettes. The assumption being your shifters pull the same as the Tiagra ones.

Cheers for that, in the end I have gone the full climbing machine... 9 speed Ultegra shifter with 9 speed mtb cassette ( 11 - 34 ) and XTR longcage rear, 9 speed chain and 38 / 48 front.
Was a bit worried that the 38 / 27 wouldn't get me up some of the real steep stuff... in last weekends race we had one pinch that I wasn't finding too easy in the 38 / 28 ... but now I will have plenty to play with.
It will be a bit more agricultural but considering most of the time it will be covered in mud and grass that is fine .