Shimano Sora: indexed front triple to friction front double?
I've done a lot of searching on this topic, but have found no answers. If a thread already exists, please forgive me. (And provide the link!)
I'd like to swap out the heavy triple crank on my girlfriend's roadbike with a nicer, lighter compact double. I'm mechanically experienced and can do the BB and crank swap no problem. Only issue is the front brifter (Shimano Sora). It's indexed for a triple, and I don't know if it can be modified to be either: (a) friction, which I'd prefer; or (b) indexed for a double. Anyone know?
Knowing Shimano, I'm guessing the answer is no, the shifter can't be modified. If this is indeed the case, has anyone used the triple brifter with a double crank successfully? Is it possible, through proper set-screw adjustment and cable tensioning, to use only two of the brifter's three index positions?
Thanks a lot in advance for any assistance.