Don't file it, you'll be there forever. Drill it:
-Drill out the back of the fork crown with 8mm bit -Drill out the whole of the rear brake bridge to 8mm (you won't be able to reach to just do the front of it). Job's a good'un
Honestly it's dead easy.
@fc9k started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
Don't file it, you'll be there forever. Drill it:
-Drill out the back of the fork crown with 8mm bit
-Drill out the whole of the rear brake bridge to 8mm (you won't be able to reach to just do the front of it). Job's a good'un
Honestly it's dead easy.