My apologies for radio silence, been busy working on motor vehicles and just yesterday started modifying the brake mount. The drag brake is for a single person bike, not a tandem. Weight load will be significantly less than a tandem. Hoping a 160 rotor will do the job as it is as large as the frame will accept. Doing this more for winter fun project than for actual application on a touring rig, however if it works out as envisioned, then I will keep it on the bike.

As for the Suntour chain stay mounted brakes, they work exceptionally well, better than cantis or V-brakes. Coupled with the Can Creek EC5 brake levers they are remarkably easy to apply, as in power brakes in a car vs the old non-power brakes (first car had 4 wheel drums and they were a handful in panic stops). Love the modulation. I have the KoolStop salmon pads on them and will put these things up against any rim brake out there including hyro rim brakes. Yes, they are that good. Road use only, off road the position collects crud and makes them less effective.