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YZ400F
The Yamaha YZ450F is a four-stroke racing motocross bike built by Yamaha Motor Corporation. It was the successor to the previous YZ426F which was discontinued in 2003. It is credited by ''Cycle World'' and ''Dirt Rider'' magazines as the bike that started the four-stroke dirt bike revolution. The 2006 YZ250F and YZ450F were the first production motorcycles equipped with titanium suspension springs. The WR450F is the enduro version of the YZ450F. Introduction For many years, the motocross world almost exclusively used two-stroke engines. AMA racing classes had two classes: 125 cc and 250 cc two-strokes, with no provision for four strokes. Most riders considered four-stroke engine technology to be largely utilitarian and uncompetitive, relegated solely for trail riding. In 1996, the AMA changed racing rules to allow 450 cc four strokes to compete in the same racing class as 250 cc two-strokes. Yamaha engineer Yoshiharu Nakayama first came up with the idea of c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
YZ400F
The Yamaha YZ450F is a four-stroke racing motocross bike built by Yamaha Motor Corporation. It was the successor to the previous YZ426F which was discontinued in 2003. It is credited by ''Cycle World'' and ''Dirt Rider'' magazines as the bike that started the four-stroke dirt bike revolution. The 2006 YZ250F and YZ450F were the first production motorcycles equipped with titanium suspension springs. The WR450F is the enduro version of the YZ450F. Introduction For many years, the motocross world almost exclusively used two-stroke engines. AMA racing classes had two classes: 125 cc and 250 cc two-strokes, with no provision for four strokes. Most riders considered four-stroke engine technology to be largely utilitarian and uncompetitive, relegated solely for trail riding. In 1996, the AMA changed racing rules to allow 450 cc four strokes to compete in the same racing class as 250 cc two-strokes. Yamaha engineer Yoshiharu Nakayama first came up with the idea of c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yamaha WR450F
The Yamaha WR450F is an off-road motorcycle made by Yamaha Motor Company. It currently has a liquid-cooled single-cylinder engine. First offered in 1998 at 400cc, it shared many components and design concepts with the YZ400F motocross model. It is basically the racing YZ450F detuned slightly for more controllable power, with a headlight and lighting coil, softer suspension, a kickstand, lower noise specifications, larger radiators and lower emissions. The WR in the name indicates a wide-ratio gear box common to most enduro or trail bikes and stands in contrast to the close-ratio gearbox essential to a motocross racer. Over the years the WR has benefited from the advances made in the YZ motocross version gaining displacement and advancements such as an aluminum frame and improved suspension. Over much of its life the weight of the WR450F has remained fairly constant ranging from 244 to 249 pounds dry weight. First generation: WR400F - 1998-2000 Yamaha introduced the WR 400F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yamaha Motorcycles
List of motorcycles manufactured by Yamaha Motor Company. First bikes * YA-1 built August 1954, produced January 1955. The first bike manufactured by Yamaha was actually a copy of the German DKW RT 125; it had an air-cooled, two-stroke, single cylinder 125 cc engine *YC-1 (1956) was the second bike manufactured by Yamaha; it was a 175 cc single cylinder two-stroke. * YD-1 (1957) Yamaha began production of its first 250 cc, two-stroke twin, the YD1. *MF-1 (1958) 50 cc, two-stroke, single cylinder, step through street bike *YDS-3 (1964) 246 cc, two-stroke, parallel-twin, it used the world's first oil injection lubrication system in a 2-stroke engine. * DT-1 (1968) Yamaha's first true off-road motorcycle. * XS-1 (1970) Yamaha's first four-stroke engine motorcycle (650 cc twin).http://www.yamaha-motor.com/corporate/historytimeline.aspx , Yamaha website timeline, accessed October 2, 2011 * Yamaha YZ Monocross (1975) First production motocross bike with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motocross
Motocross is a form of off-road motorcycle racing held on enclosed off-road circuits. The sport evolved from motorcycle trials competitions held in the United Kingdom. History Motocross first evolved in Britain from motorcycle trials competitions, such as the Auto-Cycle Clubs's first quarterly trial in 1909 and the Scottish Six Days Trial that began in 1912. When organisers dispensed with delicate balancing and strict scoring of trials in favour of a race to become the fastest rider to the finish, the activity became known as "hare scrambles", said to have originated in the phrase, "a rare old scramble" describing one such early race. Though known as scrambles racing (or just scrambles) in the United Kingdom, the sport grew in popularity and the competitions became known internationally as "motocross racing", by combining the French word for motorcycle, ''motocyclette'', or ''moto'' for short, into a portmanteau with "cross country". The first known scramble race took place ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yamaha Motor Corporation
is a Japanese multinational manufacturer of motorcycles, marine products such as boats and outboard motors, and other motorized products. The company was established in 1955 upon separation from Yamaha Corporation (however, Yamaha Corporation is still the largest private company shareholder with 9.92%, as of 2019), and is headquartered in Iwata, Shizuoka, Japan. The company conducts development, production and marketing operations through 109 consolidated subsidiaries as of 2012. Led by Genichi Kawakami, the company's founder and first president, Yamaha Motor spun off from musical instrument manufacturer Yamaha Corporation in 1955 and began production of its first product, the YA-1 125cc motorcycle. It was quickly successful and won the 3rd Mount Fuji Ascent Race in its class. The company's products include motorcycles, scooters, motorized bicycles, boats, sail boats, personal water craft, swimming pools, utility boats, fishing boats, outboard motors, 4-wheel ATVs, recreat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doug Henry (motocross)
Douglas Howard “Doug” Henry (born September 6, 1969) is an American former professional motocross racer. He competed in the AMA Motocross Championships from 1988 to 2006. He is a three-time AMA motocross national champion. Henry was inducted into the AMA Motorcycle Hall of Fame in 2005. Early career Henry was born in Milford, Connecticut and grew up on his parents' farm in the White Hills section of Shelton, CT. The rural area with extensive winding dirt roads was conducive to him learning the sport he would master. He attended Shelton High School. Henry had his first major success in 1993 as a member of Team Honda, where he claimed the 125 East Supercross and the 125 National Championship. In 1994, he repeated as champion in the nationals, beating riders such as Steve Lamson and Ryan Hughes while battling a severe stomach ailment. He later appeared on Fox's first motocross movie Terrafirma. He moved to the premier 250cc division for 1995, where he was immediately compet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yamaha Motor Company
is a Japanese multinational manufacturer of motorcycles, marine products such as boats and outboard motors, and other motorized products. The company was established in 1955 upon separation from Yamaha Corporation (however, Yamaha Corporation is still the largest private company shareholder with 9.92%, as of 2019), and is headquartered in Iwata, Shizuoka, Japan. The company conducts development, production and marketing operations through 109 consolidated subsidiaries as of 2012. Led by Genichi Kawakami, the company's founder and first president, Yamaha Motor spun off from musical instrument manufacturer Yamaha Corporation in 1955 and began production of its first product, the YA-1 125cc motorcycle. It was quickly successful and won the 3rd Mount Fuji Ascent Race in its class. The company's products include motorcycles, scooters, motorized bicycles, boats, sail boats, personal water craft, swimming pools, utility boats, fishing boats, outboard motors, 4-wheel ATVs, recreat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-cylinder Engine
A single-cylinder engine, sometimes called a thumper, is a piston engine with one cylinder. This engine is often used for motorcycles, motor scooters, go-karts, all-terrain vehicles, radio-controlled vehicles, portable tools and garden machinery (such as lawnmowers, cultivators, and string trimmers). Single-cylinder engines are made both as 4-strokes and 2-strokes. Characteristics Compared with multi-cylinder engines, single-cylinder engines are usually simpler and compact. Due to the greater potential for airflow around all sides of the cylinder, air cooling is often more effective for single cylinder engines than multi-cylinder engines. This reduces the weight and complexity of air-cooled single-cylinder engines, compared with liquid-cooled engines. Drawbacks of single-cylinder engines include a more pulsating power delivery through each cycle and higher levels of vibration. The uneven power delivery means that often a single-cylinder engine requires a heavier flywheel than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Four-stroke
A four-stroke (also four-cycle) engine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either direction. The four separate strokes are termed: #Intake: Also known as induction or suction. This stroke of the piston begins at top dead center (T.D.C.) and ends at bottom dead center (B.D.C.). In this stroke the intake valve must be in the open position while the piston pulls an air-fuel mixture into the cylinder by producing vacuum pressure into the cylinder through its downward motion. The piston is moving down as air is being sucked in by the downward motion against the piston. #Compression: This stroke begins at B.D.C, or just at the end of the suction stroke, and ends at T.D.C. In this stroke the piston compresses the air-fuel mixture in preparation for ignition during the power stroke (below). Both the intake and exhaust valves are close ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycle World
''Cycle World'' is a motorcycling magazine in the United States. It was founded in 1962 by Joe Parkhurst, who was inducted to the Motorcycle Hall of Fame as "the person responsible for bringing a new era of objective journalism" to the US. ''Cycle World'' was the largest motorcycling magazine in the world. The magazine is headquartered in Irvine, California. Regular contributors include Peter Egan and Nick Ienatsch. Previous or occasional contributors have included gonzo journalist and author Hunter S. Thompson, journalist and correspondent Henry N. Manney III, and professional riding coach Ken Hill. Parkhurst sold ''Cycle World'' to CBS in 1971. CBS executive Peter G. Diamandis and his associates bought CBS Magazines from CBS in 1987, forming Diamandis Communications, which was acquired by Hachette Magazines the following year, 1988. In 2011, Hachette sold the magazine to Hearst Corporation, which in turn sold ''Cycle World'' to Bonnier Corporation Bonnier LLC (formerl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorcycle Suspension
A motorcycle's suspension serves a dual purpose: contributing to the vehicle's handling and braking, and providing safety and comfort by keeping the vehicle's passengers comfortably isolated from road noise, bumps and vibrations. The typical motorcycle has a pair of fork tubes for the front suspension, and a swingarm with one or two shock absorbers for the rear suspension. Front suspension The most common form of front suspension for a modern motorcycle is the telescopic fork. Other fork designs are girder forks, suspended on sprung parallel links (not common since the 1940s) and bottom leading link designs, not common since the 1960s. Some manufacturers (e.g. Greeves) used a version of the swinging arm for front suspension on their motocross designs. A single-sided version of the idea is also used in motor scooters such as the Vespa. The hub-center steering as developed by Ascanio Rodorigo, on a concept associated to Massimo Tamburini is a complex front swingarm alternat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yamaha YZ250
The Yamaha YZ250 is a two-stroke motocross race bike made by Yamaha. The model was launched in 1974 and has been regularly updated and is still in production with new releases every year. Engine The original YZ250 of 1974 used an air-cooled 250cc two-stroke engine of 70 mm bore and a 64 mm stroke, which was improved semi-annually. The air-cooled motor was replaced in 1982 with a 249 cc liquid-cooled two-stroke reed-valved engine with a YPVS exhaust valve for a wider spread of power. The bore on the water-cooled engine was reduced to 68 mm and the stroke was increased to 68 mm producing a displacement of 247 cc. In 1999, the bore was further reduced to 66.4 mm and the stroke lengthened to 72 mm producing a displacement of 249 cc. The longer stroke engine resulted in a lower redline, slightly less top end power and greatly improved torque at lower RPM. The engine produces a peak at 8,800 rpm and of torque at 7,500 rpm, with a 9,000 rpm r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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