The Shelsley Walsh Speed Hill Climb is a hillclimb in Shelsley Walsh, Worcestershire, England, organised by the Midland Automobile Club (MAC). It is one of the oldest motorsport events in the world, and is the oldest to have been staged continuously (wartime excepted) on its original course, first having been run in 1905. On that first occasion, the course was 907 m in length, but in 1907 it was standardized at 914 m, the length it remains today.
Shelsley Walsh is a notably steep course by the standards of today's hillclimbs held in the United Kingdom. It rises 100 m during its length, for an average gradient of 1 in 9.14 (10.9%), with the steepest section being as much as 1 in 6.24 (16%). This makes Shelsley a hill on which power is important, and on which the gap in times between the most powerful cars and the rest is greater than at many other venues. It is also narrow, being no more than 3.66 m wide at some points.
The winner of the first event, held on Saturday 12 August 1905, was Ernest Instone (35 hp Daimler), who established the hill record by recording a time of 77.6 seconds for an average speed of 42.08 km/h. However, at that time hill climbs were not strictly speed events at all, performances being rated in terms of a formula based on power and cars of 20 hp or more being required to be four-seaters and to carry passengers.
All cars were required to carry full touring trim and a full load of passengers. The winner was calculated by multiplying the car's time in seconds by the horsepower, and then divided by the total weight (including the weight of the driver and passengers and any ballast).
According to Wikipedia