Brazing Disk Tabs to a Vintage MTB Frame
 

Is this a bad idea? If I mitered and brazed an extra tube from the seat-stay to the chain-stay under the disk braze on would that be sufficient reinforcement? I know that many coaster brakes and drum brakes attach to the chain-stays of bikes designed for use only with use rim brakes without problem.

Seems to me that disk brakes are the only difference between a new Surly Troll and a vintage MTB that costs 1/10th the price. I'm assuming I'd also have to spread the rear triangle.

the brace seems common for seat stay mount,
top of the chainstay mount wouldn't need it,
but those tab parts are not as common..
got the jig built up to keep its placement in ISO specs?

troll has sliding brake mounts as the caliper has to chase the axle when the chain tension
requires adjusting moving it.

of course Paragon sliding mounts move them both together..