Hi All! I bought an interesting book at the Kop Hill Climb on Saturday, which was a fabulous event by the way! The book is called Classic Motorcycles: BSA by Don Morley and reading it last night I learnt a lot about the rise and fall of our famous marque. One bit that I wanted to share with you is about the move from plunger to swinging arms frames in the mid-1950’s. Now I always thought that plungers were retained until 1957 because people preferred them for sidecar usage and maybe the conservative (small ‘c’) Brits didn’t like change… This may be true, but Don Morley offered a different explanation behind this transition…
“Only the Gold Star and the export version of the Gold Flash were fitted with the new all-welded, swinging arm frame. This was because BSA had difficulty in adapting its volume manufacturing process from the old lug-and-braise method to lugless-and-welded. Consequently, with the exception of that headlight cowling and a new faired-in rear number plate, all the other models remained much as before.”
Now you probably knew this already, but I didn’t know the difference in frame building techniques or why the change took 3 to 4 years to make. Interesting stuff, for me anyway. By the way, I have nearly completed the restoration of a 1954 Plunger model, headlight cowling and faired-in rear number plate included! Cheers, Simon