Has anyone ever tried to weld/braze sliding disc brake mounts on to a steel frame with a 120mm rear end, e.g. a Pompino? I'm considering buying the frame and parts I'd need to give it a go, but was wondering if anyone has done it and can give advice.
Thinking of running an ISO / 6-bolt flip-flop 120mm hub, with a disc rotor screwed to the ISO side, and a freewheel screwed on to the threaded side.
My reasoning is that I want a bike I can run single-speed when I want to, but I hate caliper and v-brakes, and I'm not a fan of any disc single speeds on the market, plus they are hard to find for cheap 2nd hand and their 135mm rear ends make running them fixed a pain.
The only issue I can foresee is a chainstay-mounted caliper clearing the seatstay (see attached), as track-ends rule out seatstay mounted calipers since you'd have to remove the brake to take the wheel out.