Indian 841

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.

Indian 841
Indian 841 at Barber Vintage Motorsports Museum, Battleground, Birmingham, AL USA
ManufacturerIndian Motocycle Manufacturing Co.
Production1941[1]–1943[2]
1 056 produced[2]
Classmilitary
Engine45 cu. in. (737 cc) 90° air-cooled side-valve V-twin [3][4]
Bore / stroke2.87 in × 3.50 in (73 mm × 89 mm)
Top speed70 mph (113 km/h)[5]
Power25 bhp[3]
TransmissionFour speed, foot shift; shaft drive[2][4]
SuspensionFront: Girder fork with coil springs and shock absorber
Rear: Plunger-type with coil springs[6]
BrakesFront and rear: Drum[6]
Weight528 lbs. (240 kg)[7] (wet)
Fuel capacity5 gal.[7]
RelatedIndian Sport Scout (engine internals)

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. "Motorcycle Hall of Fame Museum: 1941 Indian Military Model 841: The Wigwam's desert warfare bike". Motorcyclemuseum.org. Archived from the original on 2012-07-27. Retrieved 2011-02-26.
  2. 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. 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. 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 (2 October 2006). Motorcycle: Evolution, Design, Passion. The Johns Hopkins University Press. p. 40. ISBN 0801885302.
  6. Mitchel, Doug (1995). Motorcycle Classics. Lincolnwood, IL USA: Publications International. pp. 56–57. ISBN 0-7853-0889-X.
  7. Tooth, Phillip (November–December 2012). "War Horse: Indian Model 841". Motorcycle Classics. 8 (2): 61–64. ISSN 1556-0880.
  8. "Motorcycle Hall of Fame Museum: 1942 Harley-Davidson XA". Motorcyclemuseum.org. Archived from the original on 2012-07-27. Retrieved 2011-02-25.
  9. 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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