... -arc welding/co2 welding.4.Chainwheel&crank:12"-24T*89,16"-28T*102,the crank length we can make as your ... .the treatment is ED,CP,UCP.11.Freewheel:12"-16T,16"-16T,20"-18T,single speed.heat treatment.finish:black or ... is ED.15.Kickstand: Φ8.5 ,treatment is ED.16.Handle bar and handle stem:the treatment is CP,argon-arc welding ... three pcs.18.Tyre and inner tube:12"-1.75,16"-1.75,20"-1.75 and so on.Air tyre ...