Indian track racing machine

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Indian track racing machine from 1915

The Indian track racing machine (1911–1926) was a racing motorcycle made by the American manufacturer Indian . It was one of the first motorcycles with four valves per cylinder.

Development and technology

Oskar Hedström, the designer and co-owner of Indian, felt compelled, despite the triple success at the Isle of Man TT in 1911, to develop an engine for a track racing machine that performed better and was technically ahead of the competition. He wanted to be one of the first to build a motorcycle with a four-valve cylinder head. The four-valve cylinder head was well known through a 1906 patent from Hotchkiss ; the drawing of the patent already showed a hemispherical cylinder head and four radially arranged valves. In 1912, an Alycon racing engine with four valves was used in car races in France; the Peugeot 500 Sport with a four-valve engine designed by Ernest Henry was not raced until 1913.

For the existing Indian two-cylinder V-engine with 60.92 cubic inches (998 cm³) displacement, a bore of 3 1/4, a stroke of 3 43/64 inches and a cylinder angle of 42 degrees, Hedström designed a cylinder head with four valves . They were operated via bumpers and fork rocker arms and hung parallel to the cylinder axis in the combustion chamber. The carburetor, developed by Hedström himself, provided the mixture supply and the combustion was initiated by a Bosch magneto ignition. The motorcycle had no brakes, the speed was reduced by cutting the ignition; the circuit breaker was on the left end of the handlebar. The engine was started by pedaling.

Races and records

Already ready for use at the end of 1911, the Indian track racing machine won the championship on the oval course the following year . Numerous championships followed, the Indian was almost unbeatable in track races for the next few years. From 1916 to 1919, the eight-valve engine called the “big base” was also available in a series version with a three-speed gearbox in the “1916 H” model. On April 14, 1920, Ernest Walker achieved the official speed record for motorcycles over one mile with an Indian in Daytona with a speed of 167.670 km / h. The track record for the 1¼ mile, which still exists today, was set in 1922 by Curley Fredrichs on an Indian in New Hampshire . He reached 193.6 km / h during his record lap. In 1926 a revised model with the cylinder head of the "Chief" achieved 132 mph (212.43 km / h).

  • Paul-Derkum-Indian.jpg
  • 1915 Indian 8-valve board track racer (2) - The Art of the Motorcycle - Memphis.jpg

Web links

Individual evidence

  1. ↑ a b c The Art Of The Motorcycle. Guggenheim Museum, Las Vegas. ISBN 0-89207-207-5 . P. 126
  2. ↑ Helmut Krackowizer: Milestones in motorcycle history. Motorbuch Verlag Stuttgart. ISBN 3-613-01141-7 . P. 25
  3. ↑ a b Classic Motorbike No. 6/2011. P. 31
  4. ↑ Ludwig Apfelbeck: Paths to the high-performance four-stroke engine. ISBN 3-87943-578-2 . P. 13
  5. ^ Christian Rey and Harry Louis: Famous Motorcycles. ISBN 3-453-52062-9 . P. 47
  6. ↑ Classic motorcycle No. 6/2011. P. 27
  7. ↑ Jerry Hatfield: Standard Catalog of American Motorcycles. 1898-1981. Krause Publications, ISBN 978-0-89689-949-0 , p. 287
  8. ^ LJK Setright: The Guinness Book of Motorcycling. Facts and Feats. 1982, ISBN 0-85112-255-8 , p. 180
  9. ↑ Jerry Hatfield: Standard Catalog of American Motorcycles. 1898-1981. Krause Publications, ISBN 978-0-89689-949-0 , p. 320