the 5/16" is the one on TOP of the banjo - I'm asking about the one underneath the banjoSimply bearings have them at nearly £2 for two -5/16" id good luck with your search prices seem to have gone up a tad...
Not sure what to say about the YP250. I assume it is a beer fetcher strapped to the back of a motorhome and you didn't want oil dripping on your nice chrome bumper.
.
Actually the YP250 was an inner city daily ride - saw over 50,000 miles before I sold it on.