In the early days of the British motorcycle industry, it was common for small manufacturers to use “bought in” engines. Norton’s first TT winner of 1907 was powered by a Peugeot engine, and Royal Enfield started out with engines from Swiss manufacturer Motosacoche. The most popular proprietary 4-stroke engine of the 1920s by far, was made by the Tottenham, London, firm of John Prestwich & Co, sold under the brand name “JAP.” Hoping to capitalize on this market, in September 1930 the RudgeWhitworth Company announced that it would make its 4-valve engines — including the race-derived bronze head models — available to bike makers under the brand name Python. One of their first customers was the fledgling Vincent HRD Company.
During the 1870s, the licensee of the Tiger’s Head pub in Wolverhampton, near Birmingham in Britain’s industrial West Midlands, was one Daniel Rudge. A keen cyclist and innovator, Rudge’s key invention was the adjustable ball-bearing wheel hub, which rendered obsolete the plain bushings used to that date. It improved performance so much that racers using Rudge wheels had to start 10 yards back! After Rudge died in 1880, his company eventually merged with Charles Pugh’s Whitworth Cycle Company. Rudge-Whitworth was soon the most successful bike builder in Britain, building 75,000 bicycles in 1906 alone. Rudge-Whitworth introduced its first motorcycle in 1911, using an engine of its own design. The single-cylinder 500cc used roller bearings for the connecting rod and had an intake-over-exhaust (F-head) valve arrangement. The variable-speed “Multi” of 1912 established Rudge as a leading motorcycle manufacturer, but by the early 1920s, its design was obsolete. In response, John Vernon Pugh, then chief designer, decided to leapfrog the competition.
Many overhead valve engines of the day experienced valve issues. To achieve higher performance, valves were made larger. Unfortunately, these were more prone to breakage and the larger ports often led to cylinder head distortion. Four smaller valves meant lighter weight and less risk of a valve head separating, and smaller ports meant less cylinder head distortion. Engineer Harry Ricardo was working on a 4-valve engine for Triumph, and Pugh arrived at a similar solution. The 4-speed, 4-valve pent-roof cylinder head 350cc “Rudge Four” was introduced in 1924 — the same year that 16year old Philip Conrad Vincent bought his first motorcycle.
Vincent’s first foray into motorcycle manufacture is well recorded. After designing his cantilever rear suspension system while at Cambridge University, Vincent dropped out of school, and with financial support from his family purchased the trademark, goodwill and remaining component parts of the defunct HRD Motors Ltd, in 1928. HRD had a good racing pedigree, winning the 500cc Isle of Man TT in 1925, with five more top 10 finishes in the 500 and 350 TTs over the next two years. But in a failing economy, sales fell, and HRD ran out of money.
Having bought the brand, Vincent decided to cash in on the associated goodwill, naming his new company, The Vincent “HRD” Co. Ltd. Developing a new engine from scratch would have taken time and considerable investment, so the first Vincent HRDs used bought in JAP engines, though engines from Motosacoche and U.K. companies Blackburne and Villiers were also used. The engines went into a triangulated frame of Vincent’s own design, built from straight tubes welded together and with the Vincent cantilever rear suspension. Sales were disappointing, and the blame fell on the triangulated frame. The notoriously conservative British motorcyclist balked at the clever but unattractive frame, and treated the rear suspension with suspicion. While JAP engines were widely used (the Vtwins were even good enough for George Brough’s Superior), Vincent thought something more sporting than JAP’s ubiquitous 500cc overhead valve single would sell more bikes.
Though Rudge had stayed out of racing during the early 1920s, they returned for 1926 with a 500cc version of the 4-valve, pent-roof engine. Entries in that year’s senior TT yielded a 13th and 15th. Then in 1928, Graham Walker won the Ulster Grand Prix on the 500cc Rudge, repeating the feat in 1929 at an average speed of over 80mph. So impressive was this achievement, that Rudge renamed its 500cc Sports model “Ulster.” In 1930, Rudge introduced a new cylinder head design for its 350cc race bikes, with the four pushrodoperated valves set radially around the head; six rocker arms operated the exposed valves. 1930 was also Rudge’s best racing year, with a spectacular 1-2-3 finish in the Junior TT, and 1-2-6 and 7 in the Senior. For 1931, the 500cc race bike received a new valve arrangement, with parallel intake valves and radial exhaust valves, while the Special, Ulster and 500 Replica retained parallel valves. In the same year, Python 350cc and 500cc engines became available to other manufacturers.
1931 was also a pivotal year for Vincent HRD, with the arrival from Melbourne, Australia, of a talented young engineer: Philip E. Irving. The story famously goes that Irving travelled overland riding pillion on a 1929 600cc HRD motorcycle ridden by a John Gill of Bradford, England, who was completing a round-the-world ride.
Serendipitous or not, Vincent hired Irving, first to redesign the HRD frame and rear suspension layout. Irving came up with a more conventional open diamond frame of lug-and-braze construction, introduced as an option on 1932 models while the triangulated frame was phased out.
For the 1932 model year, Vincent HRD offered a choice of engines, 350cc or 500cc, with either single or dual-port JAP, and either Python or Python Sports engines. The Python Sports engine was a 499cc 4-stroke single of 85mm x 88mm bore and stroke with pushrod operated overhead valves. By 1932, Rudge had adopted the “semi-radial” 4valve layout for the 500 Sports on the basis that it was less complicated and more reliable than the full radial head, and performance differences were minimal.
Two factors contributed to Vincent’s decision in 1934 to develop his own engine. First, Rudge’s fortunes declined in the early 1930s. Metallurgy had moved on, and the 2-valve over-head cam Nortons and Velocettes were at least as reliable and were faster. In 1934, Rudge announced it would cease deliveries of the Python.
That left JAP as Vincent’s only viable source of proprietary engines. In 1934, Vincent HRD entered the Isle of Man Senior TT with motorcycles powered by a new JAP racing engine. Unfortunately, engine failures meant none of the Vincent- JAPs completed practice or the TT itself — not quite the result Vincent was looking for, and a serious blow to JAP’s reputation. So Vincent and Irving set to, and between the TT races in June of 1934 and the motorcycle show at London’s Olympia stadium in November, they completed their design. The 500cc Meteor and Comet were launched in 1935.
There were 106 Python Sports made between 1932 and 1934.