I have long thought about doing this, and now that my wife crashed the Dahon and busted up the left shifter, I think I might as well have the thing apart and see what comes of it.
I have all the parts I need except the front canti hanger, and possibly a new lighter crankset. The handlebars I have ar 46cm, which is wider than I like, but I might make do.
Older Sora 8 speed STI's.
Old Shimano Cantis from my wife's bike (will give her bike the V-Brakes and re-set the pull on her adjustable brake levers.) New pads.
New 8 speed cassette to replace the 7-speed cassette I now have on the freehub.
Old rear brake cable hanger.
Old 8 speed "STX RC" RD.
Deore Top swing/Top pull RD (48T max)
much higher angle (but shorter) stem.
A 700c skinny conversion is also possible, especially with a new fork, but I think I still want fenders and my studded tires for winter.
Someone else's example:
Dahon Espresso Road Project - ready to go by schoccaland, on Flickr
Maybe I should go with bullhorns+ STI rather than drops... but the more I look at that skinny tire version... I have a 5500 105 9 speed set just waiting to be put on something.
Which way should I go? Part of the issue I face is being six foot four and needing to get the bike as "big" as possible.
Commute is 1 mile to train, 1.5 train to work. 16 work to home if I want to get the ride in. When I ride the whole way home on the bike as built, I'm beat by the end from the weight and lack of hand positions.