I guess I need to elaborate a little more. I don't offer a lot of advice 'cause my knowledge on these bikes is fairly limited. I mostly read. I am an old metal worker in a machine shop so I forget sometimes that some things aren't that simple. I had a 2-3/4 inch 15 tooth #41 sprocket laying around and also a bearing for it. I had to bore out the sprocket and press in the bearing. You might want to try out the roller. From some of the past posts I've read, a lot of the fellas are real happy with the roller. It already has a bearing in it and it's quiet. If I remember correctly, some have gone to the hardware store and bought a small stiff "helper" spring. You should be able to attach it to one of the mounting bolts and you may have to drill a small hole in the arm to attach the other end. I will see if my wife can show me how to post a picture of what I did. It's not fancy, but works well.