Wow, I just found this guy's website . . . that's a lot of work/money to spend on a Dahon but the end result is almost exactly what I was envisioning. Though I could skip the Di2 and the gold bling, the front derailler and drop bar conversion look great. I'd use clipless pedals.

http://handsonbike.blogspot.com/p/da...alk-x20-r.html

It also seems that this and other dropbar conversions for the Dahons are unnecessarily complicated. Why not simply cut the top off the stock handlepost and have the top of a fork steerer tube welded on, to accept a standard threadless stem. Or, if height and reach adjustment are not necessary, shim the stock handlepost clamp to fit a standard drop bar? I may be missing something here.