.225 is about .008", taking that much off w/ abrasive is no doubt do-able but doing so uniformly by hand over the width of the 2 clamps seems like a really tall order. Possible to remove the clamping halves & have some one with a mill or lathe to bore out the .008" required? Seems like a big pita either way. May also try setting up a 'turning' arrangement by making clamping block (wood gobbled up with grease) that fits loosely enough to rotate bars around axis of motorcycle clamping bolt then carefully grinding down with abrasive tool of some type. Would aid in more uniform material removal, but still pretty hokey.
Live while you're alive.