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2550-06-12

American Iron Horse Motorcycles

American Iron Horse MotorcyclesAmerican Ironhorse Motorcycle Company has recalled certain 2005 Legend, Slammer, and Texas Chopper models equipped with Progressive suspension. The shock absorbers have a spring plate assembly that was installed upside down. 199 units are affected.

Models:American iron horse motorcycles texas chopperAmerican iron horse motorcycles legendAmerican iron horse motorcycles slammerAmerican iron horse motorcycles lscAmerican iron horse motorcycles tejasAmerican iron horse motorcycles outlawMotorcycle MakeupThe chassis (or frame) of a motorcycle is typically made from welded aluminium or steel (or an alloy) struts, with the rear suspension being an integral component in the design. Carbon-fiber and titanium are used in a few very expensive custom frames.Some motorcycles include the engine as a load-bearing (or stressed) member; this has been used all through bike history but is now becoming more common.Oil-in-Frame (OIF) chassis, where the lubricating oil is stored in the frame of the motorcycle, was used for Vincent motorcycles of the fifties, and for a while during the 1970s on some NVT British motorcycles. It was widely unpopular and generally regarded as a bad idea at the time. Today it is a widely used idea on "thumpers" (single-cylinder four-strokes) that usually have a dry-sump lubrication requiring an external oil tank. It has since gained some cache in modern (2006) custom bike world too because of the space saving it can afford and the reference to an earlier era. Buell motorcycles employ a similar design - the oil is held in the swingarm, while the fuel to power the motorcycle is held in the frame.Front ForkA motorcycle fork is the portion of a motorcycle that holds the front wheel and allows one to steer. For handling, the front fork is the most critical part of a motorcycle. The angle of rake determines how stable the motorcycle feels.EngineAlmost all commercially available motorcycles are driven by conventional gasoline internal combustion engines, but some small scooter-type models use an electric motor, and a very small number of diesel models exist (e.g., the USMC M1030 M1 version of the Kawasaki KLR650).The Displacement is defined as the total volume of air/fuel mixture an engine can draw in during one complete engine cycle. In a piston engine, this is the volume that is swept as the pistons are moved from top dead center to bottom dead center. To the layperson this is the "size" of the engine. Motorcycle engines range from 50 cc (cubic centimetres), commonly found in many small scooters, to 2294 cc, the largest production engine, currently made by Triumph for its Rocket III cruiser-style motorcycle.Motorcycles have mostly, but not exclusively, been produced with one to four cylinders, and designers have tried virtually every imaginable layout. The most common engine configurations today are the vertical single and twin, the V-twin, the opposed twin (or boxer), and the in-line triple and in-line four. A number of others designs have reached mass production, including the V-4, the flat 6-cylinder, the flat 4-cylinder, the in-line 6-cylinder, and the Wankel engine. Exotic engines, such as a radial piston engine, sometimes appear in custom built motorcycles.Engines with more cylinders provide more power for the same displacement, and feel smoother to ride. Engines with fewer cylinders are cheaper, lighter, and easier to maintain. Liquid-cooled motorcycles have a radiator (exactly like the radiator on a car) which is the primary way their heat is dispersed. Coolant or oil is constantly circulated between this radiator and the cylinder when the engine is running. Air-cooled motorcycles rely on air blowing past fins on the engine case to disperse heat. Liquid cooled motorcycles have the potential for greater power at a given displacement, tighter tolerances, and longer operating life, whereas air cooled motorcycles are potentially cheaper to purchase, less mechanically complex and lighter weight.An air cooled engine contracts and expands with its wider temperature range, requiring looser tolerances, and giving shorter engine life. The temperature range of an air cooled two stroke is even more extreme, and component life even shorter than in an air cooled four stroke.As applied to motorcycles, two-stroke engines have some advantages over equivalent four-strokes: they are lighter, mechanically much simpler, and produce more power when operating at their best. But four-stroke engines are cleaner, more reliable, and deliver power over a much broader range of engine speeds. In developed countries, two-stroke road-bikes are rare, because - in addition to the reasons above - modifying them to meet contemporary emissions standards is prohibitively expensive. Almost all modern two-strokes are single-cylinder, liquid-cooled, and under 600 cc.TransmissionModern motorcycles normally have five or six forward gears. Only the largest touring motorcycles (most prominently, the Honda Goldwing) and a few models that are routinely used with a sidecar or converted to tricycle configuration are fitted with a reverse gear. On some, it is not really a reverse gear, but a feature of the starter motor which when reversed, performs the same function. These motorcycles' weight (in the region of 300 kg) means they cannot effectively be pushed without the motor engaged.The clutch is typically an arrangement of plates stacked in alternating fashion, one geared on the inside to the engine and the next geared on the outside to the transmission input shaft. Whether wet (rotating in engine oil) or dry, the plates are squeezed together by a spring, causing friction buildup between the plates until they rotate as a single unit, driving the transmission directly. A lever on the handlebar exploits mechanical advantage through a cable or hydraulic arrangement to release the clutch spring, allowing the engine to freewheel with respect to the transmission.The most commonly used transmission is a sequential gearbox. From neutral, either first or second gear can be selected, but higher gears may only be accessed in order - it is not possible to shift from second gear to fourth gear without shifting through third gear. A five-speed of this configuration is commonly said to be "one down, four up," and a six-speed is said to be "one down, five up" due to the placement of the gears with relation to neutral.Scooters normally have a continuously variable transmission (CVT). CVT is a type of automatic transmission (also occasionally used in cars) that can change the "gear ratio" (gears are not generally involved) to any one of infinite arbitrary settings within the limits. The CVT is not constrained to a small number of gear ratios, such as the 4 to 6 forward ratios in typical automotive transmissions. CVTs are ideally suited to 2-wheeled vehicles because of the lack of shift shock. A conventional automatic transmission might shift shock at an unexpected moment and upset the vehicle.Final drivePower transfer from the gearbox to the rear wheel is typically accomplished with a chain, which requires both lubrication and adjustment for elongation (stretch) that occurs through wear. The lubricant is subject to being thrown off the fast-moving chain and results in grime and dirt buildup. Chains do deteriorate, and excessive wear on the front and rear sprockets can be dangerous. Many manufacturers offer cruiser models with final drive options of a belt or a shaft. A belt drive is still subject to stretch, but operates very quietly, cleanly, and efficiently. However, belt drives are limited in the amount of power they can transmit. A gilmer belt is frequently used. A shaft drive is completely enclosed; the visual cue is a tube extending from the rear of the transmission to a bell housing on the rear wheel. Inside the bell housing a bevelled gear on the shaft mates with another on the wheel mount. This arrangement is superior in terms of noise and cleanliness, and is virtually maintenance free. However, the additional gearsets are a source of power loss and add weight.WheelsThe wheel rims are usually steel or aluminum (generally with steel spokes and an aluminium hub) or 'mag' type cast or machined aluminum. At one time, motorcycles all used spoke wheels built up from separate components (see wheelbuilding), but, except for dirtbikes, one-piece wheels are more common now. Performance racing motorcycles often use carbon-fiber wheels, but the expense of these wheels is prohibitively high for general usage.TiresMotorcycles mainly use pneumatic tires. However, in some cases where punctures are common (some enduros), the tires are filled with a "mousse" which is unpunctureable. Both types of tires come in many configurations. The most important characteristic of any tire is the contact patch. That is the small area that is in contact with the road surface while riding. There are tires designed for dirtbikes, touring, sport and cruiser bikes.Dirtbike tires have knobby, deep treads for maximum grip on loose dirt, mud, or gravel; such tires tend to be less stable on paved surfaces. Touring tires are usually made of harder rubber for greater durability. They may last longer, but they tend to provide less outright grip than sports tyres at optimal operating temperatures. The payoff is that touring tires typically offer more grip at lower temperatures, meaning they can be more suitable for riding in cold or winter conditions where a sport tire may never reach the optimal operating temperature. Sport/performance tires provide amazing grip but may last 1,000 miles (1,600 km) or less. Cruiser and "sport touring" tires try to find the best compromise between grip and durability. There is also a type of tire developed specifically for racing. These tires offer the highest of levels of grip for cornering. Due to the high temperatures at which these tires typically operate, use on the street is unsafe because the tires will typically not reach optimum temperature before a rider arrives, thus providing almost no grip en route. In racing situations, racing tires would normally be brought up to temperature in advance by the use of tire warmers.BrakesThere are generally two independent brakes on a motorcycle, one set on the front wheel and one on the rear. However, some models have "linked brakes" whereby both can be applied at the same time using only one control. Front brakes are generally much more powerful than rear brakes: roughly two thirds of stopping power comes from the front brake - mainly a result of weight transfer being much more pronounced compared to larger vehicles, due to the very short wheelbase . Brakes can either be drum or disc based, with disc brakes being more common on large, modern or expensive motorcycles for their far superior stopping power, particularly in wet conditions. There are many brake-performance-enhancing aftermarket parts available for most motorcycles including brake pads of varying compounds and steel braided brake lines.In the 1980s, BMW introduced the antilock braking system (ABS) to the world of motorcycling. This life-saving advance has since been adopted for civilian motorcycles by some other manufacturers, including Honda, Suzuki, Yamaha, Kawasaki and Ducati. Some larger scooters also offer ABS brakes.SuspensionModern designs have the two wheels of a motorcycle connected to the chassis by a suspension arrangement, however 'chopper' style motorcycles often elect to forgo rear suspension, using a rigid frame.The front suspension is usually built into the front fork and may consist of telescoping tubes called fork tubes which contain the suspension inside or some multibar linkage that incorporate the suspension externally.The rear suspension supports the swingarm, which is attached via the swingarm pivot bolt to the frame and holds the axle of the rear wheel. The rear suspension can consist of several shock arrangements:* Dual shocks, which are placed at the far ends of the swingarm* Traditional monoshock, which is placed at the front of the swingarm, above the swingarm pivot bolt* Softail style monoshock, which is mounted horizontally in front of the swingarm, below the swingarm pivot boltInstrumentsWith dirtbikes excluded, almost all motorcycles have a speedometer, an odometer and a tachometer. Fuel gauges are becoming more common, but traditionally a reserve tank arrangement is used with a petcock (petrol tap) on the side of the motorcycle allowing the rider to switch to a reserve fuel supply when the main fuel supply is exhausted. There is not actually a separate reserve tank: The intake for the petcock has two pipes, one extending higher into the fuel tank than the other. When fuel no longer covers the short pipe, the rider switches the petcock to the "reserve" setting, which accesses the shorter pipe. Riders whose bikes lack a fuel gauge (most machines prior to the past few years) usually learn how many miles/km they can go with a full tank of fuel, and then use a trip meter if available to judge when they must refill the tank.AdditionsVarious additions may be attached to a motorcycle or come as an integral part of a motorcycle from the factory.FairingA plastic or fiberglass shell, known as a fairing, is placed over the frame on some models to shield the rider from the wind. Drag is the major factor that limits motorcycle speed, as it increases at the square of the velocity, with the resultant required power increasing with the cube of velocity. As can be seen from the streamlined appearance of new performance motorcycles, there is much aerodynamic technology included in the design. Unfortunately, since the 1958 FIM ban on "dustbin" fairings no major manufacturer has been bold enough to overcome the effect of the turbulence caused by the spinning front wheel, which prevents the motorcycle from cutting a clean path through the air. The "dustbin" fairing can improve aerodynamic performance without unacceptably compromising the rider's ability to control the machine, although with a weight penalty. In the absence of a fairing or windshield, a phenomenon known as the windsock effect occurs at speeds above 100 km/h, where the rider becomes a major source of drag and is pushed back from the handlebars, tiring the rider. However, these motorcycles still effectively push their way through the atmosphere with brute force.Cabin cycle solved the problem of aerodynamics by isolating driver from outside air.Modern fairings on touring and sport-touring motorcycles dramatically improve a rider's comfort and attention on long rides by reducing the effect of the wind and rain on the body. They also help keep a rider warm in cold weather, reducing hypothermia. Heated hand grips, and even heated seats, also improve rider comfort in cold weather. Some fairings now have electric windshields, which raise and lower the windshield with the push of a button to the optimum height for conditions. Originated by BMW, such windshields are now available as well on selected models from Honda, Yamaha, Kawasaki, and Moto Guzzi.Fuel efficiencyMotorcycle fuel efficiency benefits from the relatively small mass of the vehicle, compared to its passengers and to other motor vehicles, and subsequent small engine displacement. However, poor aerodynamics of exposed passengers and engines designed for goals other than fuel economy can work to reduce these benefits.Fuel effiency varies greatly with engine displacement from a low of 29 mpg U.S. (8.1 L/100km) reported by a Honda VTR1000F rider[1] to 107 mpg U.S. (2.2 L/100km) reported for the Verucci Nitro 50cc Scooter. A specially designed Matzu Matsuzawa Honda XL125 achieved 470 mpg U.S. (0.5 L/100km) "on real highways - in real conditions."