Indian 841

Indian 841

Indian 841 at Barber Vintage Motorsports Museum, Battleground, Birmingham, AL USA
Manufacturer Indian Motocycle Manufacturing Co.
Production 1941[1]–1943[2]
1 056 produced[2]
Class military
Engine 45 cu. in. (737 cc) 90° air-cooled side-valve V-twin [3][4]
Bore / stroke 2.87 in × 3.50 in (73 mm × 89 mm)
Top speed 70 mph (113 km/h)[5]
Power 25 bhp[3]
Transmission Four speed, foot shift; shaft drive[2][4]
Suspension Front: Girder fork with coil springs and shock absorber
Rear: Plunger-type with coil springs[6]
Brakes Front and rear: Drum[6]
Weight 528 lbs. (240 kg)[7] (wet)
Fuel capacity 5 gal.[7]
Related Indian Sport Scout (engine internals)

The Indian 841 was a motorcycle designed by the Indian Motocycle Manufacturing Co. for desert warfare. It pioneered the drivetrain configuration later popularized by Moto Guzzi, having a longitudinally mounted air-cooled 90-degree V-twin with shaft drive to the rear wheel.

History

Close-up of Indian 841, showing girder forks and cylinder layout

During World War II, the US Army requested experimental motorcycle designs suitable for desert fighting[1] and offered Indian $350,000 in exchange for 1,000 shaft-drive, side-valve, twin-cylinder test motorcycles. In response to this request, Indian designed and built the 841 (8 for the new engine design and 41 for the year).[7]

The Indian 841 was heavily inspired by the BMW R71 motorcycle, as was its competitor, the Harley-Davidson XA.[2] However, unlike the XA, the 841 was not a copy of the R71. Although its tubular frame, plunger rear suspension, four speed transmission, foot operated shifter, hand operated clutch and shaft drive were similar to the BMW's, the 841 was different from the BMW in several aspects, most noticeably so with its 90-degree longitudinal-crankshaft V-twin engine and girder fork.[1][2][4] Also unlike the R71 and the XA, the 841 used a heel-and-toe shift pedal with heel-operated upshifts and toe-operated downshifts.[4] The bike also had a low compression ratio of 5.1:1, meaning that it could be run on low-octane fuel, crash bars to protect the cylinders, 18-inch wheels, two separate gas tanks for a total of 5 gallons of available fuel and newly designed girder forks for better shock absorption.[7] In order to reduce costs, the new V-twin shared several internal components with the existing Indian Sport Scout, resulting in the same bore and stroke of 2.87 in × 3.50 in (73 mm × 89 mm).[3][6]

The Indian 841 and the Harley-Davidson XA were both tested by the Army,[1][4][8] but neither motorcycle was adopted for wider military use. It was determined that the Jeep was more suitable for the roles and missions for which these motorcycles had been intended.[1][8] The 841 had also been found to have gearbox problems.[9] Surplus 841s were eventually sold from the corporate warehouse in Springfield.[2][9]

Indian enthusiast Sammy Pierce used the tank and frame of his 841 along with the case and cylinders of an Indian Chief to make his P-61 American Rocket, featured on the cover of the May 1952 issue of Cycle magazine.[10]

Drivetrain configuration

Similar drivetrain configurations, using wide-angle longitudinally mounted V-twins with shaft drive, were later used on the 1953-1956 Victoria Bergmeister motorcycle, the Honda CX series, and, most notably, on medium- and large-sized Moto Guzzi motorcycles.[1][2][11]

See also

References

  1. 1 2 3 4 5 6 "Motorcycle Hall of Fame Museum: 1941 Indian Military Model 841: The Wigwam's desert warfare bike". Motorcyclemuseum.org. Archived from the original on 2012-07-26. Retrieved 2011-02-26.
  2. 1 2 3 4 5 6 7 Tharp, Dave. "The Soldier that Never Was – Indian Military Model 841". Motorcycle Online. Archived from the original on 1996-12-19. Retrieved 2007-05-10.
  3. 1 2 3 Wilson, Hugo (1995). "The A-Z of Motorcycles". The Encyclopedia of the Motorcycle. London UK: Dorling-Kindersley. p. 108. ISBN 0-7513-0206-6.
  4. 1 2 3 4 5 Charles McLendon, ed. (September 1942). "Motorcycles for Combat". Popular Science. New York, NY, USA: Popular Science Publishing. 141 (3): 118–121, 212, 214. ISSN 0161-7370.
  5. ↑ Walker, Mick. Motorcycle: Evolution, Design, Passion. The Johns Hopkins University Press. p. 40. ISBN 0801885302.
  6. 1 2 3 Mitchel, Doug (1995). Motorcycle Classics. Lincolnwood, IL USA: Publications International. pp. 56 57. ISBN 0-7853-0889-X.
  7. 1 2 3 4 Tooth, Phillip (November–December 2012). "War Horse: Indian Model 841". Motorcycle Classics. 8 (2): 61–64. ISSN 1556-0880.
  8. 1 2 "Motorcycle Hall of Fame Museum: 1942 Harley-Davidson XA". Motorcyclemuseum.org. Archived from the original on 2012-07-26. Retrieved 2011-02-25.
  9. 1 2 3 Doyle, David (Feb 28, 2011). Standard Catalog of U.S. Military Vehicles (2nd ed.). Krause Publications. pp. 17–18. ISBN 978-1-44022-799-8. Retrieved July 24, 2012. Unfortunately, the gearbox was hard to shift and trouble prone.
  10. ↑ Margie Siegal (September–October 2007). "Sammy Pierce's P-61 American Rocket". Motorcycle Classics. Retrieved 2009-08-11.
  11. ↑ Wilson, Hugo (1995). "The A-Z of Motorcycles". The Encyclopedia of the Motorcycle. London UK: Dorling-Kindersley. p. 191. ISBN 0-7513-0206-6.
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