Yamaha XV1900A

Yamaha XV1900A

Manufacturer	Yamaha Motor Company
Also called	Star Roadliner (US) Star Stratoliner (US) Yamaha Midnight Star (UK)
Production	since 2006
Class	Cruiser
Engine	1,854 cc (113.1 cu in) 4-stroke air-cooled V-twin
Bore / stroke	100mm x 118mm (3.937 in x 4.646 in)
Compression ratio	9.5:1
Power	89.04 hp (66.40 kW) @ 4,500 rpm
Torque	155.10 N·m (114.40 lbf·ft) @ 4100 rpm
Transmission	5-speed gearbox to belt drive
Frame type	Aluminium double cradle
Suspension	Telescopic forks front, rear swingarm (Link-type monocross suspension)
Brakes	298 mm (11.7 in) double disc front, single rear
Wheelbase	1,715 mm (67.5 in)
Dimensions	L: 2,580 mm (102 in) W: 1,100 mm (43 in) H: 1,125 mm (44.3 in)
Seat height	705 mm (27.8 in)
Weight	329 kg (725 lb)[1] (dry)
Fuel capacity	17 litres (3.7 imp gal; 4.5 US gal)[1]

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 is the largest Yamaha motorcycle in production.^[2]

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.^[2]

Engine

2010 engine design

The 1,854 cc (113.1 cubic inches) four-stroke air-cooled 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. Set at 48 degrees, the cylinders have a four pushrod valves, twin spark plug cylinder heads,^[3] with forged pistons having an Alumite coating to reduce friction and ceramic-composite-coated cylinders.^[2]

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.^[2]

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.^[4]

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 featuring a four-step adjustable lever. For quiet operation together with low maintenance requirements, the Midnight Star is equipped with a belt drive system.^[2]

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.^[2]

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,^[5] and special black finish to the engine and a range of custom fittings.^[3]

See also

• Yamaha DragStar

References

1. "Yamaha XV1900 (2006-current)". Motorcycle News. Retrieved 4 October 2010.
2. "XV1900 Midnight Star". Retrieved 23 September 2010.
3. "Yamaha Raider XV1900". Retrieved 23 September 2010.
4. "XV1900A Midnight Star". Retrieved 23 September 2010.
5. Bastien, Pascal (2007-10-29). "2008 Yamaha XV1900 Custom S Road Test". Retrieved 23 September 2010.

External links

• Official Yamaha XV1900A web site
• Yamaha XV 1900A Midnight Star - Engine Sound on YouTube