Originally Posted by
pinholecam
A bi-fold Dahon/Tern (and all the various good quality clones like Fnhon, Rifle, Crius, etc) will be good enough.
As for upgrades.
1. Assuming the bike comes with a 9speed RD, then add a cheap FD and fd-shifter and the chainring to a 2x; worth considering will be to swap out the usual stock square taper BB while changing the crank.
Thats about it actually.
A bike as such has high utility and is inexpensive.
Spend the rest of the money on bags that mount on the bike and a rear rack.
I just built another such bike for my son for a trip at the end of the year. (Will share some photos when I have the chance to take some)
Yep. The only tricky part is, there's no standard clamp-style FDs for the large diameter Dahon seat tube (I think 40mm?), so you need an adaptor for a braze-on style FD. My adaptor is sturdy, some of the later adaptor designs are simpler but not as strong. And because of the fat seat tube and thick adaptor, I couldn't get the FD inboard far enough for the inner chainring on my new hollow-spindle crank, so had to grind off the inboard cage top lip/flange (overkill wide and strong) at the very front where the adaptor interfered, worked great. However the Microshift FD has too stiff a spring for me, a road Shimano is better, but the linkage is larger so won't mount properly on my adaptor. For now, my setup works. Everything else was pretty straighforward.
Would have been way easier if the frame came with a FD "braze-on" (now welded) mount. Some bi-folds do.
EDIT: With 3500 feet of daily climbs, unless you are a TdF quality climber, I'd recommend having a low gear no higher than 21 gear inches in case you run out of steam and need to spin your way up. (I'd say 15 if you were loaded touring, but you said not. I may need that if I do that kind of elevation.) The bike above ranges from 21-85 gear inches, with 50/34 crank and 11-30 cogs on 20"/406 x 1.75"/44mm tires. Also, bike weight may be critical, mine is 28 lbs empty, no racks or accessories. With all the stuff I have added, it's now 55 lbs, and that's before a lot of cargo. With all the competition now in the 20" space, I think you can easily find one 28lbs or even less at moderate cost.