Driver Magazine - 2025 - issue 1 of 3 - Magazine - Page 31
BACKGROUND
At 22 years old, Percy Riley (1880–1941) started his own engine company,
supplying single-cylinder engines.
These were initially fitted to bicycles before evolving into V-twin engines
for Tricars. However, as engine performance improved, it started to
outpace the capabilities of early pneumatic tyres.
A rear-wheel blowout on a Tricar could be a serious issue. The best case
scenario was it taking two men a few hours to fix; at worst, it could flip the
entire vehicle. There seemed to be an obvious solution… a car with a
wheel on each corner.
Tricars remained popular, but by 1905, they had started using transversemounted V-twin engines.
While the exact timeline of the four-wheeled Riley’s development isn’t
entirely clear, we do know that it was designed in response to the
growing demand for side-by-side motoring and improved safety.
Riley’s first model made its public debut at the Motor Show in October
1906, announced as a 1907 model. However, prototypes would have been
built and tested throughout 1906.
Riley’s usual approach involved rigorous chassis testing to iron out issues
with suspension, steering, braking etc before finalising the body design.
Once the chassis was deemed fit for purpose, prototype bodies would
have been mounted for further trials, including visual assessment. Only
after this stage was the final design approved for production.
Around the same time, the Stepney wheel made its appearance.
Patented in 1904, this was an early form of a spare wheel.
It was basically a rim fitted with an oversized tyre that clamped onto the
car’s existing wheel, allowing drivers to limp home. It quickly became so
popular that a dedicated factory was set up in 1906.
Percy Riley, however, dismissed the Stepney wheel as "not an
engineering job" and set about designing a more advanced detachable
wheel system.
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