The word “venerable” is often used to describe certain types of motorcycles. But if ever that adjective was well placed, it was for the BSA C15. 

The 250 C15 was introduced in 1958 (in Europe, then it came to the US a year later). Three versions were available: Trials, Scrambles and Street.  A super sport (the Sports Star or SS) version was made available in 1961 which, besides lots of extra chrome for the American market, had competition cams, a high-compression piston, a large bore carb and a beefed-up crankshaft assembly (roller-bearing big end with heavy-duty flywheels).

The C15, in its various guises, was produced from 1958 to 1967.

Heritage

The C15 can trace its heritage back to the C11 C12 and even the Triumph Terrier designed by  Edward Turner. Noticeable differences over the C15’s predecessors were the gearbox location - the C15 now deployed ever increasing design trend to use unit construction engine/gearbox cases – and the cylinder which was now vertical. 

The rest of the C15’s design was conventional for the time, albeit the bike came fitted with a swing-arm and dual shocks. 

The brakes were not a strong point of the early C15’s.The bike had 6” diameter single leading shoe brakes front and rear with just 7/8” of shoe width! Later models had a full width brake and the competition machines enjoyed 7” x 1?” items.

The suspension was again typical for the period with hydraulic front forks and internal oil damped rear shocks giving 5” and 2?” respectively.

Fuel Consumption

Performance for a learner bike, as they were called in the UK, was good. The bike had a fuel consumption of around 90 mpg and a top speed of around 75 mph.

However, most riders kept to the recommended 55 to 60 mph for touring use. 

The versatility of the design is obvious from its use as a street bike, a scrambler, and a trials bike. Interestingly, the C15 won national level motorcycle competitions in both Scrambles and Trials, with riders like former world champion Jeff Smith taking honors. 

Considering how long the C15 was in production, and how many were subsequently sold, classic buyers should not be put off by early reports that the C15 had a vulnerable bottom end. In truth, the reports of crankshaft and gearbox problems on those early machines was limited to a few machines. 

These early reports were primarily created by young riders (UK riders were restricted to a max. of 250-cc when the C15 was introduced, which resulted in the C15 being ridden to, and beyond, its limit on a daily basis).  However, the early crank types were not as strong/reliable as the later caged roller bearing versions. Besides early crank problems, the gearboxes were prone to issues with the layshaft bearing. An improved gearbox was fitted from 1960 on, and a redesigned unit was introduced for 1966 which incorporated a needle roller bearing for the layshaft. 

As one owner was quoted in 1965 as saying: “I covered 20,000 miles and the bike was off the road a mere two days in 21 years. “

Prices

For early (1959) examples of the C15, in excellent condition, the following represents typical prices in today’s market in the US:

Street version $4100

Trials $5,000

Scrambles $11,500

 

Further reading: 

Classic Motorcycle Values, Conditions