As the sign on the bike said... :
"BSA 500 cc Square Four
Made of 2 Sunbeam 250 c Scooters welded together,
the front one is turned around.
And the empty gearbo used as a mounting point.
Linked with a chain, and 4 ignition points at one plate.
2 Carburettors, the front a little camouflaged for the look."
Shown at the BSA Summercamp 2023 in Earnewald, NL
regards
Joergen M
( I was there ;o)
