Hi, I bought Shimano road calipers for an older steel frame. The rear brake bridge hole is smaller than the Shimano recessed nut, so the nut won’t seat and the center bolt ends up too short to tighten (pics).
What’s the best fix?
• swap the caliper center bolt for a longer M6 one?
• use a smaller recessed nut / different mounting hardware?
• drill/counterbore the bridge (hard to access) — safe or bad idea?
Thanks.
by Comfortable-Ice610