re: multispeed BMX.
I've done it before. I welded my own derailleur hanger, but you can buy them from -- Bicycles, Bike parts, Mountain Bikes, BMX, Road Bikes, Haro Bikes, KHS Bikes, Felt Bikes at Niagara Cycle Works for $5 or less for BMX and other bikes. The problem with BMX is the short chainstays cause some chain friction, but it works. http://motorbicycling.com/f26/my-700c-single-speed-2-stroke-5480-3.html#post90292
I've done it before. I welded my own derailleur hanger, but you can buy them from -- Bicycles, Bike parts, Mountain Bikes, BMX, Road Bikes, Haro Bikes, KHS Bikes, Felt Bikes at Niagara Cycle Works for $5 or less for BMX and other bikes. The problem with BMX is the short chainstays cause some chain friction, but it works. http://motorbicycling.com/f26/my-700c-single-speed-2-stroke-5480-3.html#post90292