The Yamaha XV1900A is a motorcycle manufactured by the Yamaha Motor Company and sold in the United States through Yamaha's Star Motorcycles division. It was the largest Yamaha motorcycle while in production.[3]

Development

The Yamaha XV1900A cruiser was developed to exploit the large displacement end of the market for large cruisers. Yamaha had a well established range of big "Star" cruisers which went up to the Wild Star 1600 cc but there was a need to redesign the engine to meet anticipated exhaust emissions regulations and the opportunity to update the styling, which had remained largely unchanged for a decade.[3]

Engine

2010 engine design

The 1,854 cc (113.1 cubic inches) four-stroke, air-cooled, 48 degree V-twin engine was purpose-built to deliver maximum torque at 2,500 rpm in the 55 to 75 mph (90 to 120 km/h) range used for motorcycle cruising. Each cylinder has four pushrod-activated valves and twin spark plugs.[4] To reduce friction, the forged pistons have an Alumite coating and travel in ceramic-composite-coated cylinder bores.[3]

With an undersquare bore and stroke of 100mm (3.937 in) x 118mm (4.646 in), the engine has a compression ratio of 9.5:1 and is the first Yamaha cruiser motorcycle to be equipped with the compact Exhaust Ultimate Power Valve (EXUP) four-stroke power valve system previously only found on their line of high performance sports motorcycles.[3]

An unusual feature of the new engine is a special 'Pent-roof combustion chamber', designed to increase the efficiency of gas flow. The engine also has counter-rotating balancers on both ends of the crankshaft to reduce the vibration typical of large V-Twins.[5]

Transmission

The engine's output is transmitted via a wide-ratio five-speed gearbox and compact new transfer case, with power delivery controlled by a hydraulic clutch, the XV1900A Midnight Star is equipped with a belt drive system.[3]

Frame

A lightweight long wheelbase (1,715 mm or 67.5 in) frame was designed using aluminum die casting to minimize weight, with a double cradle design to provide the strength. Suspension consists of a die cast aluminum swinging arm and a hidden single horizontal rear shock absorber and large diameter front forks.[3]

Raider version

Starting in 2008, a custom version was produced in limited numbers featuring a lowered seat, lengthened front forks, a wider 210 mm rear tyre, the widest on any Yamaha motorcycle,[6] and special black finish to the engine and a range of custom fittings.[4] The Raider was discontinued for 2018.

See also

References

  1. ^ a b Roderick, Tom (September 17, 2013). "2014 Star Roadliner S Review". Motorcycle.com. Retrieved June 8, 2014.
  2. ^ a b "Yamaha XV1900 (2006-current)". Motorcycle News. Retrieved 4 October 2010.
  3. ^ a b c d e f "XV1900 Midnight Star". Retrieved 23 September 2010.
  4. ^ a b "Yamaha Raider XV1900". Retrieved 23 September 2010.
  5. ^ "XV1900A Midnight Star". Retrieved 23 September 2010.
  6. ^ Bastien, Pascal (2007-10-29). "2008 Yamaha XV1900 Custom S Road Test". Retrieved 23 September 2010.
Allikas: https://en.wikipedia.org/wiki/Yamaha_XV1900A
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