My son has been cruisin the hills of Denver on a single speed until now. He now has a 3 speed with custom Rat Fink shifter made from a Rat Fink bobble head and an old beer tap.
Thanks! The tires are Nirve 20x2.15" I had to use the wood plank and hammer approach to widen the frame, here's a link to Amazon
http://www.amazon.com/Nirve-......-2-12 ... m_sbs_sg_7