'B' series girders

[militaryron]

I'd say definitely like those fitted to at least the B2 for 1934/5/6.  Ron

[Steve.S]

I've just had another thought. If you scrape away the paint from the outside of the links, you should be able to see the BSA piled arms stamping of 3 rifles leaning up against each other. Above this should be a letter. This will indicate the year of manufacture. Hope this helps.

[Greenfield]

Looking through old parts books, these links were fitted to a number of bikes, mainly lightweights, around the mid 30s.
I can't make out the piled arms, but above the part number is E1-3 if that makes sense to anyone.
Someone in the past has spent time and money on the bike, but when it came to sourcing hard to find parts, they gave up. These links are clearly hard to find.
I started checking the electrics and found a new voltage regulator. Instead of attaching the wires with hollow bullets, they were jammed in place with bits of wood! I'll say no more.
Happy days