Originally Posted by
LWaB
Front mechs can cope with a wider range than you think, if you are mechanically sympathetic as you change gears. After all, wide range double cranksets (e.g. 46 & 28t chainrings) used to be seen fairly often on touring bikes, as were half-step + granny set-ups with 20t jumps between small and middle chainrings.
That's encouraging LWaB, as I haven't seen those large doubles. I'll go hunting & see what I can find.
John