12 Innovations For Which Royal Enfield Deserves Credit

Royal Enfield was one of the original and classic English motorcycle manufacturers. The company built its first bike in 1901 and ceased operations in 1970. Present-day Royal Enfield is entirely separate and operates in India as part of the Eicher Motors Limited group.

In 1954, when the Indian army ordered 800 Bullet 350cc singles, a relationship began that gradually morphed from importing whole bikes to assembling knocked-down kits to more and more actual manufacturing in India. Finally, the Bullet became 100-percent Indian-made.

Royal Enfield in England ended in the usual way; longtime leader Frank Walker Smith died. He and his successful network of personal business relationships were replaced by “numbers men” who knew little about the motorcycle business.

They played mergers and acquisitions with what was left until nothing remained. India actually began to export the Bullet to Britain in 1977. To this day, it remains a 1955 model, updated with AC electrics.

1901 Today, reverse-rotating engines are appearing on sportbikes like Ducati's Panigale V4, but Royal Enfield's 1901 prototype had that very feature just by crossing its drive belt. What was Enfield's reason for doing this? Not to speed up roll maneuvers, as in MotoGP. Almost certainly its reason was to get more "wrap" on the engine pulley—to stop slippage.

1911 Normally we honor Indian for bringing a two-speed countershaft gearbox and all-chain drive to the Isle of Man TT races, but Royal Enfield had those features on a production model in the same year.

1912 This one is with us today, but Royal Enfield was the first to build a vanes-and-rubber-blocks cush drive to protect its Model 180's drive chain from roller-splitting engine firing impulses.

1913 Royal Enfield became the first British motorcycle maker to adopt a pumped recirculating lubrication system. One pump supplied oil to the big-end bearing through drillings in the crankshaft, supplied from an external tank. The other pump picked up oil in the crankcase and returned it to the tank. Yet most other makers persisted right through the 1920s with total-loss systems that relied on splash. All modern bike engines have pumped recirculating oil systems.

1934 Having reservations about the fatigue life of roller connecting rod big-end bearings, engineer Tony Wilson-Jones made a white-metal-coated floating plain big-end bearing for Cecil Barrow's TT racer. It worked. Today the vast majority of bike engines have plain rod and main bearings. Normally we credit Triumph's Edward Turner for his adoption of plain rod bearings on his 1937 Speed Twin, and Honda for use of plain bearings on all crank journals of its 1969 CB750 inline-four.

Royal Enfield Continental GT 650 Twin Combines Classic Looks With Latest Tech

1935 Harley-Davidson's EL of 1937 featured partial enclosure of its OHV valve gear, but Royal Enfield's three-valve Model LO had full enclosure in 1935.

1938 Normally I credit Velocette with adopting Y alloy for the cylinder head of its KTT roadracer in 1937, but Royal Enfield put such heads on its 70.0mm x 90.0mm 350cc Bullet production bike just a year later. Y alloy's extraordinary hot strength made it possible for the first time to retain valve-seat inserts in air-cooled aluminum heads that cooled much better and weighed one-third to one-half what previous iron or bronze heads had weighed.

1939 Floating plain big-end bearing became standard on Royal Enfields.

1946 Royal Enfield engineer Tony Wilson-Jones designed the company's telescopic fork with hydraulic two-way damping. Its design was very similar to what I found on Japanese roadrace forks of the 1970s.

1948 In November, Royal Enfield's 500cc parallel twin was given a highly fatigue-resistant hollow crankshaft of nodular iron only a year after the material had been commercially introduced in Detroit. Nodular iron became the standard material for mass-produced automotive crankshafts.

1948 Late in the year, the Royal Enfield Bullet 350 appeared with swingarm rear suspension. Yes, Velocette pioneered a swingarm on racebikes of the late 1930s, but Enfield put it into production at a time when other English production bikes had crude, stiff sliding-pillar or spring-hub rear suspension.

1950 Wilson-Jones delivered a paper to the Institution of Mechanical Engineers on the subject of wobble and weave, the two major forms of motorcycle instability. This was one of the earliest formal treatments of motorcycle stability.