How do you grind rod bearings to fit large filets?

Most Chinese cranks need the bearings tweaked. A few (the better ones) don't. I use a utility knife and remove material a little at a time. You have to be very careful because the bearing material will squish and push up the bearing surface if you're not careful and patient. Make sure you remove enough to get the true rod side clearance. The bearing should not be the part that sets that clearance.