hi all. as title realy .

if by twin you mean double chainring then a "normal" front mech works fine, you just use the high/low adjust screws to stop the mech shifting the chain up and off the larger ring. works fine for me on both my bikes using a SRAM X.9 front mech on one and a deore on t'other, both running truvativ stylo AM 2.2 double&bash.

The only MTB one is the SRAM XX, most of which are due into the country on the 6th January at the fairly eye watering cost of £106.

Road double mechs are available from anywhere.

i've got a hone double mech that would disagree with the above post, i believe slx is also available as a double.

or of course there is the shimano SLX, bought mine for 23 quid from merlin. dont know what they cost now though…

Damn, of course there is. I tend to think of double as big/middle, as opposed to middle/inner.

The SLX one will only do up to 36t, so it depends what double you're running.

thanks all.
yep njee20 36 middle.slx it is then.

is this the one
http://www.chainreactioncycles.com/Models.aspx?ModelID=27692

the problem is my deore keeps dropping the cain.22/36 on a fsa gap megaexo.any thoughts gang.

May be the right one, that's a bottom swing(cage below the clamp)and may or may not fit your frame depending on suspension design etc.

http://www.merlincycles.co.uk/mountain-bike-front-derailleurs/shimano-slx-front-mech-double.html

thats the top swing version for £23 on merlin as i said. However if its your chain that keeps dropping it probs isnt because of the mech. Is your chain too long? Have you tried a chain tensioner such as the blackspire stinger???