something to keep in mind, I switched to bmx chains on both my 2 & 4 stroke bikes & works much better. I have no more chain streching, much smoother & quieter. also allows for more clearance at rear tire & frame. I have about 500 miles on one of my bikes since switch & still has not streched. bmx chain fits with no mods. 415 chain doesn't fit sprokets that great anyway!