BSA Parts List 1970, A50, A65

Information

BSA Parts Catalogue for 1970 Twin Cylinder Models
Re-printed coil bound copy of the factory publication, A4 page size.

Covering Frame and Engine Numbers (at start of production year)

500cc models
1970: A50 Royal Star: A50R-

650cc models
1970: A65 Thunderbolt: A65T-
          A65 Lightning: A65L-
          A65 Firebird Scrambler: A65F-

In 1969 a new numbering system was introduced using a two letter prefix for the month and model season year. 

The first letter designates months as follows:
A: January  B: February  C: March  D: April  E: May  G: June  H: July
J: August  K: September  N: October  P: November  X:  December

The second letter is the year code:

D: July 1969 to July 1970 for bikes made for 1970 selling season.

Numbering started at 00101 and carried across all models.