Greetings, I am looking for a folding bike that would be appropriate for long-distance rides, such as centuries. I currently have a Downtube Mini that is absolutely perfect for commuting, taking aboard public transit, and storing in the office. However, even when I am really cranking on the bike, I don't seem to exceed 10-11 mph. Unfortunately, this means I can't participate in long-distance rides because 100 miles at 10 mph would equal 10 hours, and obviously no one rides for 10 hours straight at maximum speed with no rest or meal breaks.
Are there racing-type folding bikes available that I should investigate--ones that would support riding at an A (or at least B) pace? It would be even better if they were in the $500 range (that is, similar to a Downtube). I'd really like the bike to fold, so I can still store it in my closet and take on trains. It can have large wheels, though, as I'll continue to rely on my Mini for commuting.
Thanks for your suggestions and advice.