I have a Surly Long Haul Trucker frame and I am moving to a 9 speed cassete and a Sugino double crankset. I was looking at an XT but don't know if I need a down or up swing.
It's based on what your frame is wired for. If the cable comes down from the top you need a top pull. If it routes under the BB you need a bottom pull.
Beyond that it doesn't really matter. The quality difference in most derailluers is nill and it's not really a precision item anyways.
OK. My cable is routed under the bottom bracket. Thanks for the clarification.
Problem Solver also makes a bolt on bracket thingy that you can use to convert a top pull to a bottom pull.
There's also a German company that makes a similar conversion piece. I hope Alan Lucas still has the link because I don't.
IMO the bottom pull designs are superior. Less prone to clogging and seem to have a bit better actuation.
I'm thinking XT might not be rated up to 48 teeth.
Just checked, it isn't. If you are running a compact double, your best bet is a road front derailluer.
What matters most is your shifter, I am guessing you are running a bar end shifter if it is a LHT. If it were me I would go with a bottom swing bottom pull 105. It should work great with a bar end shifter and a double road crank (compact or standard drive). Make sure you get a 9 speed derailleur, 10 speed ones are narrower.
if its friction and bottom pull, nearly any road derailleur (other than a ten speed), provided it fits around your seat tube, should work for you. I found an old suntour at free ride and have been pretty happy with it.
