I am the original owner of a late 1980's Specialized Sequoia with Dia Comp Royal Grand Comp long reach nutted brake calipers. I am planning to do some touring and find the braking performance way below par--even without the extra weight of paniers on it. I have already tried many different brake pads through the years with little or no change.
In researching changing the calipers, I came across the problem most of you are familiar with--my nutted type calipers are not made anymore (at least I havent found any newly designed ones) although long reach modern calipers are made, but in recessed nut form only. I want to use these modern calipers to upgrade the braking performance of my bike.
I came across Sheldon Brown's cnversion procedures:
Because the trend toward recessed mounting and toward short reach calipers happened simultaneously, most short-reach calipers come set up for recessed mounting. Medium- and long-reach calipers usually come with longer centerbolts for conventional mounting.
Mounting recessed calipers on older frames
Rear: Front calipers for recessed mounting have bolts that are long enough to mount in back, if you substitute the appropriate washers and a 6 mm nut.
Front: Here are 3 options:
1. Drill out the back of the fork crown (8 mm or 5/16 drill bit). This is actually quite easy to do with a handheld electric drill, since you're only enlarging an existing hole.
That's it if you can get two front calipers. Sometimes, you may have to deal with a pair of brakes, with one long and one short bolt. If you used the long one in back, you can use the short one in front two different ways:
2. Drill out the back of the fork crown and use an extra-long recessed nut. These nuts are commonly available for use in carbon fiber forks.
3. Use the short recessed nut, but don't put it through the back of the fork. Instead, push it up into the inside of the steerer from the bottom. You can reach a 5 mm Allen wrench in through the hole in the back of the fork, and poke the short caliper bolt in from the front.
You may need to shorten the recessed nut slightly to get it to fit inside your steerer.
My questions are these: Have any of you used this procedure? Were there any difficulties in drilling out the fork crown as described or any other part of the procedure? Do you have any pictures of the finished product? Did you find the upgrade worthwhile--did you have significantly better stopping power?
Thanks in advance