The number of spokes should be divisable by the number of holes in your sprocket. The Chineese bikes that these motors were originally made for had 40 spoke wheels so the kits came with 5 hole sprockets. The standard American hub is a 36 spoke, the five hole drive sprocket didn't fit well so hence the nine hole sprocket. I'm thinking that the nine hole won't have a proper fit but probably could be finessed into place...Kelly