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Worked for the GPO
1888 Commenced cycle racing
1893 He became the first rider to exceed 25 miles of riding in one hour.
1897. On the Crystal Palace track he broke all the cycle records from six to 32 miles inclusive. In one hour he cycles 32 miles 448 yards. 
1897 August 3rd. 'The first race which has taken place between a motor-bicycle and a safety pedalled in the ordinary way was decided at Coventry last evening. J. W. Stocks, on the safety, which experienced two punctures, covered 27 miles 210 yards in an hour. The motor was 300 yards behind.'
1904 'STOCKS, J. W., 28, Brook Street, London W. Alter ten years of successful racing on the cycle path, turned his attention to motoring, in the autumn of 1897. His first cycle race was at Hull, in 1888, and from 1896 and 1897 he held all records from one mile to one hour, and in the latter, his final year on the path, won the 100 kilometre championship, at Glasgow. On the occasion of his last appearance on the track, he covered 32.75 miles in the hour (then the world's record). In 1899 covered 434 miles on an Ariel tricycle inside twenty-four hours, a record which he has not yet beaten. Took up the management of the de Dion business in 1902. Drove a Napier car in the 1903 Gordon Bennett race, but mistook the road, and ran into a wire fence, disabling the car.' 
1907 Director of De Dion-Bouton
1907. "Stocks J. W. 10 Gt. Marlborough St, London W. Car 24 h.p. de Dion. Has driven nearly 150,000 miles. Hobby; Shooting. After ten years of successful racing on the cycle path turned his attention to motoring in 1897.
His first cycle race was at Hull in 1888, and in 1896 and 1897 he held all records from one mile to one hour, and in the latter, his final year on the path, won the 100 km championship, at Glasgow. On his last appearance on the track, he covered 32 miles in the hour (then the world record).
In 1899 covered 434 miles on an Ariel tricycle inside 24 hours.
In 1902 journeyed from Land's End to John o' Groats on an 8hp de Dion in 2 days 14 hours, including all stoppages.
In 1906 drove a de Dion car from London to Edinburgh, without stopping the engine, in 20 hours. Took up the management of the de Dion business in 1902. Drove a Napier car in the 1903 Gordon Bennett race. Also drove a Napier car in the Gordon Bennett eliminating trials in the Isle of Man (1904). Club: ACGBI" 
1910 Biographical information and image at Automotor Journal 19100205