I recently purchased a second hand frame and un-drilled forks from a lovely user of this site with a view to getting the forks drilled to take a brake on the front end.
I took it to my LBS and they were reluctant to drill the forks for two reasons:
1) The forks don't have a flat surface for the brake to sit against (as in the face of the crown is curved). I think I could get round this with a recessed spacer (I have seen on older frames).
2) They weren't confident with amount of material which would be left in the crown once the forks were drilled.
Any thoughts with how much is not enough in terms of material?
All guidance appreciated.