Thanks to everyone for your replys. Kevin,I was suspicious of some sort of kit or option because the application seemed kind of random and really didn't follow a pattern. Like two bikes,same year same model,one with the drum and the other with a disc. I like the drum simply for the appearance. Unless a person is racing,the drum will suffice just fine. As long as you realize you limitations and ride accordingly,all will be fine. I've put thousands of miles on choppers with a drum rear and a spool on the front with no problems.