The BSA B50 was produced in 3 different variants – the SS (Street Scrambler), T (Victor Trail), and the MX (Motocross) that you see in front of you today. Designed to compete off-road, the MX was built between ’71 and ’73, though some were also rebadged and offered as the Triumph TR5MX after BSA went out of business.
Expect 34 horsepower out of the out of the 499cc single, to motivate 240 pounds of bike. For more on the B50 line, check out this buying guide from Sump Publishing.
This example has some surface scratches but it’s claimed to run and sound great, having spent the last 40 years(!) in display in a private collection. Though everything is said to be original, the bike had new seals and gaskets installed in 2012. Find this B50MX for sale in Huntington Beach, California with bidding up to $4,300 and the reserve not yet met