Motorized bicycle sprocket alignment tool

I designed this tool in order to properly center the rear sprocket on my motorized bicycle conversion. This is a typical chinese 2 stroke kit where the sprocket is bolted to the non-drive side spokes of your bicycle wheel.

I'm not sure of the consistency of these conversion kits and just as well each bicycle may be different. Take a look at the design and compare measurements to your own bicycle. I've included a picture of the interface on my particular bike, a cruiser with a 3/8" axle and a coaster brake.

OD: 1.465"
ID: 1.133
center diameter (axle): .370"
Internal height: .290"
Overall height: .4"