I'm building up my new Pista and attempting to install the front brakes. Unluckily for me, the bolt that holds the brake on to the fork (the 5mm allen) is too long. I compared against my road bike, which has a carbon fork and the roadie has a thicker cross section. So the brakes I bought doesn't fit on the Pista's fork (the chrome unicrown fork.)
Here is a photo for reference - not mine.
The brakes I tried were $30 Shimano 550s. Suggestions for another brake caliper or alternate installation options?