Hi. A friend of mine has a frame which to all looks to be M20. However instead of a normal frame number there is nothing on the headstock, but on the lug under the seat is stamped 66-4035. Anybody got any ideas please ???
Bsa provided spares for all parts of the WM20. It is a army spare front frame section.I have one hanging in my shed that came of a M20 built up of army surplus parts in 1947.BSA only put the part No on the frame if it was a spare,not if it left the factory as a complete bike.
66-4035 is the part number for the front frame section of early war machines later ones are 66-4037.
Interestingly there is one machine listed in the post war key cards with frame number 664035 (card 413b) and three with 664037, presumably they were spare frames at some point to have these numbers stamped on, and when they were issued they should have had the correct number for the machine added, either way when a return was made someone recorded any old number they found, it also seems likely that many of the key cards record the engine number because it was easier to find.
Could we see some pictures of the frame and number please.
There are many weird numbers in the matchless Key Cards too, hundreds and hundreds, but I don't think many engine numbers were noted down as frame numbers, for BSA or Matchless.