Sram/Shimano front derailleur compatibility
Are X-7 Sram thumb shifters compatible with Shimano front derailleurs? I know that with rear derailleurs Sram X-7 are 1:1 and Shimano 2:1, but is that also true for the front? I assumed they were incompatible, but then I noticed bikes such as the Cannondale Adventure Headshock use X-7s with a Deore front derailleur.
I'd like to use a Shimano 105 front mech with an X-7, so I can use a 52tooth triple crankset on my commuting bike (Specialized Sequoia, flat handlbars) which the Sram X-Gen front derailleur won't accommodate (44tooth max).
Answers appreciated - the bozos down my London Islington local bike shop argued amongst themselves.