Living in Elkhart, Indiana; have built three center-frame "60-cc" motorbikes from kits bought from a nice guy in Phoenix. I work out of my home office, but I find myself thinking up little useless errands so I can ride them every day -- even in mid-January! In my experience, a 1960s- or 1970s-vintage Schwinn cantilever frame (Typhoon, if possible) is an easy install with very little metal-bending required. Anyway, these things are a hoot! Not very speedy, but the looks you get are priceless.