Spacers are different. Disk mag caliper mount acts a a pacer on one side, (factory frame),. That wont make a difference if your putting on a hard tail, (you have to make spacers anyways). Also the MC mount for the rear disk would have to be reconfigured for a hard tail, not the same but you have to reconfigure the Drum brake pivot to suit a hard tail frame. Jut an extra bracket or 2 to make up for the MC and Reservoir