I'm having trouble with the sliding dropouts on my '06 Kona A. The serrated washers have dug into the frame and now the bolts won't slide freely in the slot. I can file out the slot to fix this but I don't want the problem to recur again. I'm thinking of using larger flat washers but am worried that they won't hold the dropouts in place.
The ideal solution would be to have a screw through the dropout which seems to be the norm these days. Do you think it would be safe to get this done by a local machine shop? Is there a better solution?