Indian 841
Type of motorcycle
From Wikipedia, the free encyclopedia
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 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) |
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]