A couple of years ago I bought someone's project bike. It is a Nirve Sidewinder Chopper with a 80cc engine. It has a Shimano Nexus internal 3 speed hub with coaster brake. The hub has failed. I have read that the coaster brake hubs are not good for motorized bikes. So I am looking for a replacement hub assembly and would like to upgrade to disc brake. Should I look for a geared hub or just go with a direct drive hub with brake?