Hi, I have a vintage one speed coaster brake Rollfast bicycle that I am motorizing. Being that the spokes are old I wanted to use a sprocket adapter to keep the tension off of them. However, all of the sprocket adapters I find require a 1.5" diameter rear hub while my rear hub is a 2" diameter. I know this sounds like a large rear hub, but I double checked against other bikes and it is 2". Am I stuck with having to use the ragjoint or do I have other options. Any help is greatly appreciated!! Thank you.