Hi all
I’m going to be running 1 x 9 on my new HT build. I’m looking to use an 11-36 rear cassette and a 34T front ring. I’d like to use a GS (medium cage) rear mech. Would this work ok or would I need to drop to an 11-34?
Some mechs are listed as 34t max/11t min. Is this the same for all GS mechs?

I was running 1×9 with 32 tooth chainring and an an 11-34 cassette and a Medium SRAM caged derailleur.
I’ve since changed to a 2x setup 38-26 and it works fine.
I have a ‘need’ for 35 capacity ( 34 minus 11 + 38 minus 26 ) and the SRAM medium cage has a capacity of 37 so in theory I could run 11 – 36 in this set up.
You have no change on the front and only a need for 25 capacity ( 36 minus 11 ) so all should be good. I believe the 34 tooth is the capacity of the GS mech not the lagge cog size

http://singletrackworld.com/forum/topic/shimano-xt-gs-mech-with-36-11t-cassette

Excellent, thanks