An Early and Rare British Military Machine

With the return of BSA and the debut of their beautiful 650 Gold Star, we thought a brief look back at the history of the brand would be in order, and specifically one of their limited-run machines from the 1930s, the 1935 J35-12 Twin. Our model in photos is the beautifully restored edition on display at the Throttlestop Museum in Elkhart Lake, Wisconsin, USA.

By the early 1900s, Birmingham Small Arms Company LTD (BSA) had become a major British industrial powerhouse, a group of companies that manufactured everything from military and civilian firearms, automobiles and parts, steel and iron castings, even hand, power and machine tools, as well as bicycles.  In 1910, BSA ventured into motorized bicycles with the debut of their BSA 3 1/2 H.P. at the Olympia Show in London. They sold out of every one they produced for the next three years. BSA Cycles LTD was off and running.

In the years between the World Wars, BSA Cycles saw explosive growth in military, commercial and civilian sales, marketed as affordable motorcycles with reasonable performance. With solid reliability, an abundance of parts and wide dealer support, BSA would soon claim of motorcycles in England, “One in Four is a BSA”. Their bikes were a mixture of sidevalve and OHV engines, offering a wide range of performance options for varying roles.

By the 1933 Olympia Expo, BSA displayed a 14-model motorcycle range, with over 60 bikes brought to the show. One of them was the J34-11, an attractive 498cc OHV twin. The bike drew great interest and enthusiasm at the show among the civilian as well as military show attendees, and the British War Office placed an order for some 700 machines between 1933-36.

In 1935 BSA tweaked a few elements on the J34-11, introducing redesigned forks, a new foot shifter mechanism, a speedometer atop the front forks instead of in the tank panel, and dubbed the new machine the J35-12 Twin. The bike was 20 per cent more expensive than a comparable OHV single of the day, yet only slightly more powerful. Only about 126 of this specific model were produced, all for the British Army War Office from 1935-36.

These beautiful machines are extremely rare, both in J34 and J35 trim, and highly prized. This particular bike, with its E15 frame number prefix and 3-speed gearbox, began life as a British Army contract machine, and was originally equipped with a sidecar. The motorbike was diligently restored without the sidecar and featured in England’s Classic Bike magazine, Winter 1978/79 issue.

Once the most dominant motorcycle manufacturer in the world, we were thrilled to learn of BSA’s resurrection. And now with the debut of their all-new 650 single Gold Star, we hope renewed interest in the brand’s illustrious history will accompany their rebirth, there are so many fascinating machines in their antiquity. For more on this particular BSA J35-12 model, click below, then follow their simple instructions to get a code and enter their virtual museum:

Throttlestop Museum


*photos by Throttlestop Museum, info sourced from Throttlestop,, and Wikipedia.


Submit a Comment

Your email address will not be published. Required fields are marked *