Originally Posted by Loch
. . . My commute is 5.5-6 miles one-way and a slight uphill with a couple of pretty minor hills. I usually average 14-15 mph going to work (uphill). Should I be able to maintain this speed on a Curve?
On the way home I can average 19-22 mph or more depending on how hard I want to push it. Can a Curve handle those speeds? With the stock gearing? With modified gearing?
Maybe. I doubt if I could, but sounds like you're a stronger rider. I'd think other than gearing, a limiting factor would be that this isn't the most aerodynamic bike around. I don't have a bike computer on mine, but I did take my GPS unit on one 11 mile trip. Max speed was 28 mph (must have been down hill). Average showed as 13 mph. The GPS unit keeps computing average speed when you're not moving, so my moving average would have been a little faster. I suspect that this would have been fairly typical for me on this bike. I wasn't trying to go my fastest, and obviously, other people might go a lot faster anyway, but I wouldn't expect this to be your speediest bike. I definitely wouldn't think it would compete with the Speed Pro.
There's a thread on the Dahon forum by somebody who has just modified his Curve D3 with an 8 speed SA hub. Of course, if you wanted to go that route, there's also the Downtube Mini.
Something that would also be nice is to see a picture or video of a man about 5'11''-6' riding the bike, to get an overall idea of the fit and size of the bike. Dahon usually shows there bikes with small women on them that done even have the seat tubes properly extended, so it's really hard to get an idea of just how well it might fit. . .
I'm 5' 7", so can't help you there, but I did take some measurements that might give you an idea. I put the both the stem and the seatpost and the max height mark and measured the distance to the floor. Saddle (Brooks B67) 40 inches, top of handlebar, 38 inches to the floor. Saddle (from center of seatpost) to center of handlebars, 25.5 inches. Of course, I put both of these much lower for myself. Please take these measurements as rough approximations, but I hope it helps. I suspect a taller person might feel a little cramped, but I don't know. Not my problem.
Hopefully others will be able to help you more with the other questions. I don't plan to take this bike in a suitcase, and haven't yet had reason to remove either wheel.