Engineering: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
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
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 "Motorcycle Hall of Fame Museum: 1941 Indian Military Model 841: The Wigwam's desert warfare bike". Motorcyclemuseum.org. http://www.motorcyclemuseum.org/asp/classics/bike.asp?id=72.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Tharp, Dave. "The Soldier that Never Was – Indian Military Model 841". Motorcycle Online. http://www.motorcycle.com/mo/mcmuseum/i841.html.
- ↑ 3.0 3.1 3.2 Wilson, Hugo (1995). "The A-Z of Motorcycles". The Encyclopedia of the Motorcycle. London UK: Dorling-Kindersley. p. 108. ISBN 0-7513-0206-6. https://archive.org/details/encyclopediaofmo00wils_1.
- ↑ 4.0 4.1 4.2 4.3 4.4 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.
- ↑ Walker, Mick (2 October 2006). Motorcycle: Evolution, Design, Passion. The Johns Hopkins University Press. p. 40. ISBN 0801885302.
- ↑ 6.0 6.1 6.2 Mitchel, Doug (1995). Motorcycle Classics. Lincolnwood, IL USA: Publications International. pp. 56–57. ISBN 0-7853-0889-X. https://archive.org/details/motorcycleclassi0000mitc/page/56.
- ↑ 7.0 7.1 7.2 7.3 Tooth, Phillip (November–December 2012). "War Horse: Indian Model 841". Motorcycle Classics 8 (2): 61–64. ISSN 1556-0880.
- ↑ 8.0 8.1 "Motorcycle Hall of Fame Museum: 1942 Harley-Davidson XA". Motorcyclemuseum.org. http://www.motorcyclemuseum.org/asp/classics/bike.asp?id=71.
- ↑ 9.0 9.1 9.2 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. https://books.google.com/books?id=Ljdma-SYU0gC. Retrieved July 24, 2012. "Unfortunately, the gearbox was hard to shift and trouble prone."
- ↑ Margie Siegal (September–October 2007). "Sammy Pierce's P-61 American Rocket". Motorcycle Classics. http://www.motorcycleclassics.com/legendary-riders/2007-09-01/indian-hot-rod.aspx.
- ↑ Wilson, Hugo (1995). "The A-Z of Motorcycles". The Encyclopedia of the Motorcycle. London UK: Dorling-Kindersley. p. 191. ISBN 0-7513-0206-6. https://archive.org/details/encyclopediaofmo00wils_1.
 |  |
