Hi just found this site by pure accident ,I am in the process of rebuilding my TriBsa, I first built it in 1967/8 using a triumph 500 unit engine and a B31 BSA frame with Norton road holder forks, I tend to get carried away when working on the bike, what started as a tidy up progressed to a total rebuild I am now fitting a Grimeca 4 ls front brake and alloy yokes no doubt there will be other items to come , must admit it is easier to build a special /café racer now than it was 40 years ago as there are lots more parts made back then it was make it yourself .
John