Clamp on brakes are not a great solution. The fitting moves all the time (as some people in this forum has experienced)
Also don't even think of drilling. The bridge in those stays has thin walls, it will provably loose all resistance when you brake a couple of times. It will end up bending and you will ruin the frame.
Invest on a cheap road frame with horizontal dropouts or even a VISP as CasaEsteve said. Something that you can use as winter bike.
Clamp on brakes are not a great solution. The fitting moves all the time (as some people in this forum has experienced)
Also don't even think of drilling. The bridge in those stays has thin walls, it will provably loose all resistance when you brake a couple of times. It will end up bending and you will ruin the frame.
Invest on a cheap road frame with horizontal dropouts or even a VISP as CasaEsteve said. Something that you can use as winter bike.