Hi Bikerbob, it could still be that your bike left bsa in 56 but was a 57
I say this as there are a few grey areas, my bike being one of them.
This has just come up for me as I am going through the re registering for a b31, on the form I had to put year of manufacture, which would technically be 48 according to the Vmcc uk, but it is a 49 model according to the published bsa numbering system, this being cos bsa introduced new models some time around August the "year before". So I decided to register as a 49.
The practice of making new models prior to the calendar year is still common practice for many car and bike makers today. Maybe so the new models are in the showrooms in plenty of time for the calendar year to start.
I've also read bsa used a July summer holiday factory shut down to change over production lines to new models, but also conversely sometimes used up previous years parts on the new models. My A10 frame is an oddball in that respect having still got an extra lug for a 55 style rear rod brake
that later 56 bikes did not have
My A10 (engine and frame) left bsa in dec 1955 according to the bsa despatch records, but is a 56 model so with Ariel hubs.
Using year of registration confuses things even further, if a bike sat in a showroom for a year it could very well become a 57 that was made in 55!
These kind of post remind me of my very first restoration project which was over 20 years ago. I bought a BSA basket case which I assumed was A10 I recieved with it a dating certificate issued by the Vintage Motorcycle Club which stated that the engine and frame numbers were from 1957. The engine although in bits was 1957 as I thought the frame was but when I started the restoration I found that certain parts were from different years ie it had the ariel hubs but the front forks were earlier. On completion of the restoration I got an age related plate and it is registered as a 1957 A10 Gold Flash. Some time later I applied through the BSA owners club when I became a member for a dating certificate, I then learned that the engine was 1957 but the frame left the factory in 1956 and had a 500cc Shooting Star engine fitted. Now the BSA owners club will only recognise a model by it's frame regardless of what engine is fitted I relayed all this info to the person I sold it too but he was not concerned he just liked the bike as it was. I seen him last year and he has had the bike about 4 years now and is well pleased with it but has now fitted an electric start to it of his own design, works great. I learnt a lot from that first restoration particularly when buying a basket case.
