Spanner sizes? On British bikes? Arcane is the best word I can think of.
Best to use the correct spanner if you don't want to round the heads off.
For my Triumph TR6, acquired new and s/h spanners and sockets in Whitworth (aka BSW), BS (British Standard), BSF (British Standard Fine), UNC (Unified Course), UNF (Unified Fine), CEI (Cycle Engineer's Institute). There are others. Each of these has different sizes for nuts & bolt heads and different threads-per-inch.To simplify matters (!) Triumph made an attempt to move towards standardised thread sizes in the late 60's which means parts from one year might not fit a different year.
Working on that Triumph, I spent a lot of time trying to identify correct thread sizes and also parts in general. The company had a policy of 'improving the breed' which meant that they kept on changing things. Where possible, the changes were brought in annually as each new year-model was introduced but sometimes things were changed within a year too.To add to the confusion, part numbers were sometimes changed although the part remained the same. And sometimes a part made to a new spec kept the same part number as the superseded item. Doh!
One notorious instance is the oil pressure switch on the twin cylinder bikes. The thread was changed, from a tapered fitting to parallel (or it might be the other way round) but the part number is the same. Result is that a lot of timing covers were busted by people fitting the wrong oil pressure switch.
Fortunately, there is a lot of information about all this on't internet. Unfortunately, much of the information on't internet is contradictory. One person's firm opinion or memory against another's.
My advice would be to find a good supplier - one you can trust. LP Williams are very good and I think they specialise in the triples. The search facility on their website is a good place for identifying superseded/new parts numbers and equivalent parts. And I found they gave good advice by email. There are no doubt other good companies and probably some Stateside.
I have lots of spanners and sockets in all the above denominations and would happily give you them - if only you were closer.
They are just such an iconic bike.
so I'm going to trim a front fender (for the front, naturally), and use addition front fenders to fab up a rear fender. I'm not worried about it, 'cuz they're going to be painted, not chrome.
