The rear brake on my 1981 Interstate has always been weak in my opinion. I have replaced the pads and the rotor looks fine but you really have to push hard on the pedal to get much stop action. I don't think it would be possible to lock the rear wheel at running speed even if you wanted to. I have ridden newer wings and I feel much more stopping effect from the rear brake. The brake does work will stop the bike if pressed hard but most of the real stop is coming from the front. I have drained and bled the lines and the pedal is not soft. As I am thinking about selling the bike this is probably something I need to address. Could there be a glaze on the rotor or do if need to simply start replacing things like the caliper or MS? Any advice will be appreciated.