Hi, I picked up a Dahon Dream on craigslist for *free*. It's in poor condition, stored outside for awhile. Needs some rehab. The seller gave it to me for free because the folding latch's pivot mechanism is broken. One of the tabs welded onto the frame (which the pivot goes through) broke off. I'll have a 3/4" square (by 1/8" thick) piece of steel welded on. I was excited to receive a project bike. I've wanted a folder for awhile. So, this works well. I get to make my own bike starting at zero cost. Learn more about components, repair, etc. in the process.
The biggest change I want to make is: replace the tourney derailer with an internally geared hub. The rear dropout is 126-127mm.
1. I see Sturmey Archer 3 and 5 speeds in that size.
2. Prowheelbuilder.com in Las Vegas sells custom length spokes. I can get really short ones.
I also want to get a hub with a coaster brake so I can remove the rear V-brake, cleaning up the appearance of the bike.
I'm inspired to do these changes because 1), I saw a KHS Manhattan iPed and liked its simplicity. It has a 3-speed IGH with coaster brake. Very clean look. The only thing I didn't like is that it's a bit small with 12 and 16" tires. It also doesn't fold. But, at that smaller size it doesn't have to. 2) When googling about the "Dream" model, I found a thread on this forum from a guy in Singapore who replaced his derailer with an Alfine 8-speed IGH. (See the footnote below.). That planted the seed too.
1. Are there any "gotchas" anyone can warn me about. I'm pretty good at working on bikes. I think I can re-lace the wheel. I'm just concerned whether an IGH and coaster brake are "drop-in" replacements.
2. My area is mostly flat. I think a 3-speed would be fine. Does a 5-speed IGH introduce greater maintenance/failure potential? (does the extra internal cogs and things come at a greater long-term cost?). If there aren't any significant downsides (beyond cost), I think I'd go with the 5-speed.
 It's a model which was (still is) sold in China, Singapore, etc. It has stickers saying "USA Technology" with red/white/blue flag decals. They really play it up as a USA brand. It seems to be identical to the Boardwalk. It's just not made for the US market. Perhaps it has differences like high-tensile steel instead of cromoly, cheaper components, etc. From what I can tell, a few were purchased by enterprising individuals and sold on eBay a few years back. The one I have was purchased by an American living in China who brought it back to the US. It seems like there's a few in the US. But, not many.
For photos of a Dahon Dream converted to 8-speed Alfine IGH, see this thread. He calls it a 16" wheel. But, my tires say 20".