Hello,
The Dahon single speed look convertable. They have a lengthy warranty on the frame too =)
Having a BMX handle bar, the Puma looks good too. How customizable are these bikes? Can I add BMX gryos?
A BMX bike can probably fit in my trunk if taken apart. I would have to take it out to go snowboarding though. I would need a lock and the pegs would be available to thieves when left unattended. Someone took 2 lug nuts from my car at an attended parking lot. The wheel almost fell off on the freeway.
Most BMX frames are made of chromoly - chromium-molybdenum steel (wiki). Adding couplers might be possible. Placing them near the gears is popular. I doubt that area is slammed often while grinding, otherwise the gears would get deformed. Unless the threads get deformed, the couplers would still unscrew if dinged.
I’d like to keep everything under $600, including accessories like helmet and pegs. I think I could retrofit it for $200 or less. Silver brazing might cost $45 to $60 per hour for labor. Materials costs should be minimal. SS BTCs are only sold to professional frame makers but a professional machine shop might be able to get them. Regular steel couplers on the cheap might also. SS couplers look expensive because they’re a specialty and propriety part. If retrofitting myself or finding a suitable folder fails, I’ll get two bikes instead =)
~jw