Engineering Magazines

Motorcycles have been around for more than ten decades. During this time, motorcycle engines have developed through tweaking and reworking items to get the best performance. There have been more than one dozen engines, but some never met with success. Cost efficiency and customer satisfaction brought failure to a number of motorcycle engines.

All motorcycle engines are fueled by gasoline. To best understand engine types, it is important to understand how an engine works.

A pole called a rod cranks inside the engine and creates a draft that pulls both gasoline and air into a chamber called the cylinder. Inside the cylinder, a piston and rod quickly move up to push the gasoline and air into a smaller space where it meets the spark plug. The spark plug produces a spark between its two metal pieces.

Once the spark plug gives off a spark, the gasoline and air explode. This pushes the piston down, which in turn drives the belt or chain. This action is called torque. The movement of the belt or chain causes the rear wheel of the motorcycle to revolve. A motorcycle’s performance is determined by how many cylinders are inside the engine and how they are arranged.

Single cylinder engine:

A single cylinder engine has one cylinder and one piston. Single cylinder engines are used in all off road motorcycles. The single cylinder provides a lot of torque, but also a load of vibration. The vibration is loud and one of the qualities that dirt bike race fans crave during a race.

Twin cylinder engine:

Logically, twin cylinder engines have two cylinders. The cylinders are placed together at an angle. Usually the cylinders are positioned at a 90 degree angle, but there are exclusions to that standard. A twin cylinder engine produces more power because there is more torque and more fuel used. Twin cylinder engines do not vibrate as much as a single cylinder engine.

Now, as stated above, there are exceptions. The boxed or boxer design finds cylinders placed side by side. This produces even less vibration, but adds a new issue. The cylinders tend to jut out the side of the bike, which makes it hard to take sharp corners. Another issue is the tremendous heat that the cylinders project; it makes leg protection a necessary evil.

Triple Cylinder Engines

A three cylinder engine finds the cylinders included in a head. This type of engine offers a load of power, but it also requires more parts. Each cylinder requires an additional fuel injector and carburetor. The more cylinders included on an engine, the higher the engine RPM. More RPM means more power. Triumph makes motorcycles using three cylinders and boy can they fly!

Four Cylinder Engines

The four cylinder engine is just like the three cylinder engine only it has the additional cylinder and therefore weighs more. As is true of any engine, more cylinders equal more power and smoother sailing.

It is important to consider how much size and power you require in your motorcycle. If you are taking your bike off road, you need a bike with plenty of torque and a low rpm to make it up hills and quickly navigate corners. For off roading, stick with a single cylinder. A double cylinder is your second choice.

If your main purpose for riding a motorcycle is riding through traffic and along roads, do not purchase a bike with less than a twin cylinder engine, although a three or four cylinder engine is a better idea.

A decade ago motorcycles had speed, looks, and style. They have certainly improved with each passing year. Year after year motorcycle manufacturers get more innovative, produce faster, lighter and more comfortable motorcycles, and learn what works and what doesn’t. What are the favorites from 2007?

- Yamaha V Star 1300 Tourer.

These motorcycles have a V2 engine with an electric starter and a liquid cooling system. The seat was 28.1 inches and the dry weight was 668 pounds. It was made with a double cradle frame and a telescopic fork front suspension with a swingarm rear suspension. These motorcycles had single disc rear brakes and double disc front brakes. They have a fuel capacity of 4.88 gallons.

- BMW R1200GS

These motorcycles have a two cylinder boxer engine. They also have an electronic fuel injection with an electric starter. These motorcycles had oil and air cooled engines and a 6-speed gearbox. At 438 pounds, they were meant for speed. These off road motorcycles came in desert yellow metallic, rock red metallic, ocean blue metallic, or granite gray metallic. Though the fuel capacity is a whopping 5.28 gallons, the consumption is 1.45 gallons for every 6.2 miles.

- Yamaha WR 450 F

These are also off road motorcycles. They have a single cylinder engine, with a liquid cooling system. At just 246 pounds, it is nearly two-thirds the weight of the BMW R1200GS motorcycles. The front suspension is a telescopic fork, the rear a swingarm. The fuel capacity on these motorcycles is a mere 2.10 gallons. These motorcycles had single disc brake systems for both front and rear.

- Yamaha FZ1 Fazer

These naked motorcycles had in line four engines with an electric starter. They also had a liquid cooling system, a final drive chain transmission, and digital ignition. Like the BMW R1200GS, these Yamaha motorcycles weighed 438 pounds. The frame was aluminum die cast and the front suspension was telescopic upside down forks. The rear a swingarm suspension. These motorcycles had double disc front brakes and single disc rear brakes. Fuel capacity on these motorcycles is 4.76 gallons.

- Harley Davidson VRSCX

These custom or cruiser motorcycles have a V2 engine. They have an electronic sequential port fuel injection system and liquid cooling system. The seat is a mere 27.1 inches high and the weight 637 pounds. These motorcycles are 5-speed with a final drive belt transmission. The front and rear brakes are both single disc four piston. These motorcycles came in two tone mirage orange pearl or brilliant silver pearl. It has a 5 gallon fuel capacity.

- Victory Vegas Jackpot

Like the Harley Davidson VRSCX, these motorcycles are also custom or cruiser motorcycles. With a V2 engine, an air cooling system, and final drive belt transmission, it has many of the same features as the Harley Davidson VRSCX motorcycles. It has an electronic fuel injection system and a 6-speed gearbox. These motorcycles had an even shorter seat at 25.7 inches high. Though the seat was lower, they were a bit heavier weighing 659 pounds. The fuel capacity was 4.5 gallons and colors included black, orange crush, or sunset red.

Ever since 1932 BMW has been making motorcycles that fall in the high-end class and that are regarded as being amongst the highest quality motorcycles.

They are known for excellence and for providing some of the most enjoyable motorcycle rides around.

BMW first introduced the R32 BMW motorcycle in 1932 and have been developing that particular style of motorcycle into something that has fan clubs all over the world.

This first BMW motorcycle had a peculiar engine, known as the “boxer twin” engine. It was designed for air cooling and its two cylinders protruded from opposite sides of the motorcycle.

Later during the BMW motorcycle development they also developed more traditional four cylinder motorcycle models.

Not only did BMW manufacture road bikes, they also branched out into off-road motorcycles and have made a name for themselves there as well.

Apart from the association with quality through the BMW logo and name, BMW motorcycles also attract loyal fans because the motorcycles give comfortable rides without sacrificing sportiness and performance.

Apart from some of its off-road models, the BMW motorcycle generally is a big motorcycle. However, drivers of these motorcycles will tell you that they handle like a dream.

Today they are four different series of BMW motorcycles. These are the F, G, R, and K series.

The F series has a four stroke, four valve engine and has a chain drive to the back wheel. The G series is an off-road motorcycle that BMW developed in conjunction with Aprilia. The R series motorcycles still have their trademark protruding cylinder heads but they have been improved upon over earlier models. The K series has also been developed into a motorcycle technological wonder. Both the R and K motorcycle series come with powerful engines that can drive a small car.

If comfort, style, technology, and stylishness appeal to you in motorcycles, then the BMW motorcycle will definitely be on your shopping list. On the one hand they come with a high price tag, but on the other hand you know that you are buying BMW quality, comfort, and style.

A motorcycle is typically a two-wheeled vehicle run by a small, loud engine. These vehicles are basically motorized bicycles, but are structured with heavier, sturdier and more complex parts, implying that a motorcycle is more machine than bicycle.

Motorcycles have various uses, but the obvious primary use is to ride, to serve as a form quick transportation. Other uses: military and law enforcement, sports/racing, touring, and serving as a symbol of freedom, depending on who is riding it. Motorcycle conventions also allude to yet another purpose for the motorcycle: a show piece! Motorcycles, like automobiles, are also works of art for those who are mechanically inclined or like to showcase their unique and innovative machines (concept bikes).

Motorcycles: Types

Road Motorcycles: motorcycles built for riding on paved and public roads. These motorcycles have shallow treads and 125cc engines capable of reaching 100 mph (160km/h). Some can go over 125 mph (200 km/h). These aren’t designed for racing, but merely for public transportation. They have license plates, blinkers, and other accessories necessary for riding on public roads.

Cruiser—reminiscent of the style of American machines during the 1930s through the 1960s. These motorcycles are designed for long distance riding and provide some comfort. Harley Davidson, Excelsior, Henderson, and the Chopper are cruisers.

Sports bike—performance bikes that are usually lighter and smaller in structure than the cruiser. These motorcycles are racing bikes and have four-cylinder engines ranging 600cc to 750cc. “Super bikes” can also provide up to 1,000cc.

Touring bike—these motorcycles offer large displacement parts, to protect from inclement weather and heavy winds; high-torque engines; comfortable, upright seating positions; and large capacity fuel tanks for long-range mileage. Types of tour bikes include: Full-dress Tourers, Standard Tourers, Global On off Road Tourers, and Sports Tourers.

Naked bike—reduced in parts to its essentials, this bike emphasized function, performance, and ergonomics over the appearance that is a preferred feature of the sports and tour bikes. These motorcycles are also referred to as “street” bikes. The Yamaha Seca II is a fine example.

Scooter—Motor Scooters are short-distance motorcycles with small wheels (357 mm or 14 in. in diameter) and engines in the swing arm. Typically, these run less than 125cc, but some larger scooters exceed 250cc. One popular scooter is the Honda Lead 80.

Moped—a bicycle/motorcycle hybrid with a two-stroke engine that goes up to 50cc. These have demanding licensing in some localities. Their popularity dropped in mid-1980s, but they are still used today.

Off-road bikes—these include dirt bikes and are built for rougher terrain. They have larger, deeper-treaded tires, small engine, long suspension travel and high ground clearance, and no street accessories. These motorcycles have engines that comprise two-strokes at a single cylinder or four-strokes at a single cylinder, and can go as low as 50cc or as high as 750cc, depending on age of the riders and the size and style of the engine. Trial bikes, which go no more than 250cc, are off-road motorcycles. These are used for Motocross and Enduros.

“Dual-Sport” and Adventure-Touring—these are “on-off road” bikes. They are similar as the “off-road” motorcycles, but they are equipped to ride on public roadways as well.

Farm bike—a variant of the trial bike, this motorcycle was used by dairy farmers in New Zealand during the early 1960s. These are low-pressure motorcycles used for easy transportation.

Derny bike—a specialized motorcycle used in track cycling for blocking air-resistance for racing bicycles.

Towing bike—designed by a Swedish company, this motorcycle has a high-torque engine and retractable trailer for towing cars and light trucks. The only one in existence is the Retriever, an altered form of the Honda GL 1800 old Wing.

Concept bike—these are prototypes created to measure the response to innovative designs, new and unique technologies, cost effectiveness, and other factors. Most are never realized, but a small few are released in compromised combination form, taking into consideration marketing realities, public reaction and preference, and manufacturing capabilities.

Motorcycles are the rage of the road—and off the road. These machines are as inspirational as they are dangerous, and they require as much respect as they do training and practice to operate. If treated well, motorcycles will treat riders well.