Upgrading Brake Calipers

I have a 1983 Bianchi which has single pull Modolo brake calipers. These a less expensive knock off of Campagnolo Nuovo Record/ Grand Sport calipers of that era. I would like to upgrade the calipers to a more modern double pull variety. The Modolos are mounted to the fork or seat stay cross brace with a threaded end shaft, which is the same diameter as the hole in the fork/brace. It extends through an is held by a regular hex nut and a washer on the outside.

The modern calipers use an internal threaded insert collar with a hex key (allen) end which extends into the fork/brace and screws on to the caliper shaft to take the place of the nut. The shaft has a shoulder on the caliper side the same diameter as the hole in the fork/brace, and a reduced sized threaded area which accepts the insert collar.

Will the modern brake calipers work on the vintage frame without drilling out the holes in the fork/brace? I'm sure going to forget about this upgrade if enlarging the holes is the only way to do it. I could potentially ruin the frame and or fork if I screw up! Any advice would be appreciated

 

Not without enlarging at least the rear hole of the fork. You can use a modern front brake on the rear and use a nut to secure it but modern front brakes 'shaft' isn't as long as the older brakes. PLUS you need to measure 'reach', the distance from the center of the frame/fork mounting hole and the rim to ensure if you do et 'modern' brakes, they reach the rim.

It really is no big deal to enlarge the rear hole of the fork. I have done it many times. Many brakes are sold as singles as well, so you can buy 2 fronts, use one on the rear(reverse the pads tho!!).