We first ran into the problem when we got our boat's firts modern main. North said that the current slugs they use for the clew are slightly smaller than they were 20 years ago, whent he booms were made. We cut an old clew slug off a 1979 Ulmer main, had north stick it on our 1999 main, and the problem went away. (We still keep a OS line through the clew, in case, but it's never taken load) Food for thought.
- David