The Ultimate Guide to Motorcycle parts

The engine is the beating heart of a motorcycle, and the powerplant that makes all your two-wheeled dreams come true. All engines work on the concept of internal combustion, hence the name Internal Combustion Engine (ICE). 

The inside of an engine is surprisingly simple. It is essentially an enclosed chamber that gets a steady supply of air and fuel. This mixture of air and fuel is ignited by spark plugs, causing it to combust and expand rapidly. 

As the fuel expands inside the cylinder, it moves a piston. The piston (or pistons) is in turn connected to the crank that spins and moves the rear wheel. 

Once the crank develops momentum, it pushes back on the piston, causing any burnt gasses in the cylinder to be expelled via valves that lead to the exhaust system.

The performance of an engine can be increased by tweaking the air-fuel ratio, adding lighter parts that are easier to move with less effort, using different fuels that provide a better burn, or even adding aftermarket parts such as turbochargers and superchargers. These increase the amount of air being delivered to the engine, which allows more fuel to be ignited. 

More air + more fuel = more boom!

The next part of the equation is your motorcycle’s suspension setup. This setup is designed to give you enhanced control over the machine by managing the friction between the tires and the road. 

In fact, if you didn’t have any suspension on your motorcycle, it would lose its stability, going over even the smallest of bumps. 

Motorcycle suspension is usually made up of a spring and a dampener. These are designed to take most of the impact when you go over a bump, thus isolating the bike from the rider. 

All bikes have a front forks suspension and rear suspension in the form of either a swing arm or a hydraulic dampener. Some models allow you to adjust the amount of preload, which in turn lets you configure the settings to suit different terrains. 

Stock suspension parts can be swapped out for aftermarket setups that work to improve dampening capability, or give better feedback from the road, or just make the ride a bit more comfortable. 

The exhaust system starts at the engine and features various pipes, filters and valves that give your bike the unique sound it makes. 

But the primary function of an exhaust system is to transport exhaust gasses outside the engine. All modern exhaust systems have catalytic converters which reduce emissions by converting harmful greenhouse gasses to less damaging gasses. 

Your motorcycle’s exhaust system also plays a huge role in the performance and power figures iit puts out. Generally speaking, higher flow exhausts i.e. exhaust systems that support higher flow of exhaust gasses in a given amount of time result in higher power figures. 

Once again, exhaust systems made of lighter materials help reduce weight, which in turn improves your bikes power-weight ratio. Lighter weight also makes handling and maneuverability a lot easier. 

To understand why wheels are so important for your motorcycle’s (or any vehicle’s) performance and driving dynamics, we must first understand the concept of unsprung mass. 

Put simply, your motorcycle’s  unsprung mass is the mass of everything below the suspension. 

This includes the bottom part of the suspension (the part that moves), the wheels, the tires, brake discs and calipers, any drivetrain components such as the chain or shaft drive, and the various bolts or cables holding it all together. 

Since all of these parts are below the suspension, they are considered as one unit. And when your bike drives over a bump in the road, all of the unsprung mass moves in unison. 

Lower unsprung mass means the whole unit can move faster. Moving faster allows it to soak up bumps more efficiently and thus perform better to keep the bike and rider stable. 

Wheels tend to be the largest and heaviest components of unsprung mass. That is why getting wheels that weigh less improves the riding dynamics of the bike, by making the suspension more responsive. 

Tires are arguably the most important part of your motorcycle. They are the only parts of the bike that interact with the road and are responsible for keeping the whole thing planted on the road surface. 

Rubber tires ‘stick’ to the road surface, keeping your bike stable. Rubber grips the pavement, which also allows you to lean your bike further into a corner. 

Tires are also part of your motorcycle’s unsprung mass, which means they have a huge impact on the driving dynamics and feel of the bike. In fact, lighter tires can improve the ride quality and performance of your vehicle. 

Similarly, you can get tires made of different compounds of rubber or ones with different tread patterns. These will perform better in different conditions. 

For example, off-road tires have large knobs and thick tread to help them dig into loose dirt and gravel on the trail. However, these tires can make the ride very uncomfortable on pavement.  

Winter tires are made of a softer compound, which gives them better traction in cold conditions. The flip side is that they aren’t as good as summer tires at dispersing heat, so they may experience more blowouts in warm conditions. 

Another example is drag slicks. These types of tires are specifically designed for use on a ‘prepped’ drag strip or track. In these conditions, the tire can offer the highest amount of grip and traction. However, they are not recommended for use on the street, as they don’t have any tread which is used to evacuate water in wet conditions. 

All the ‘go’ in the world is useless if there isn’t just as much stopping power to back it up. 

Most modern bikes have a disc brake setup, where brake pads housed inside a caliper grip a brake rotor connected to the wheel in order to slow the bike down. 

Braking performance is usually dictated by how much braking force can be applied safely. When you brake, the friction between the brake pads and the rotor generates a lot of heat. Excess heat can cause the brakes to become ineffective. 

In normal conditions, this immense heat is dissipated into the surroundings and braking performance is preserved. However, in very hard braking scenarios, the brakes don’t get enough time to cool down, which can reduce the performance of the brakes. 

Here again, you can get different types of brakes made of higher quality materials. Normal steel brakes can only withstand a certain amount of heat and will experience ‘brake fade’ i.e. a loss in braking performance after that. 

However, get a set of carbon-ceramic brakes, which can withstand a lot more heat, and you can brake harder, longer, and more frequently before experiencing brake fade. 

The final drive components are the parts of the motorcycle that transfer power from the engine to the rear wheel of your motorcycle. They’re called ‘final drive’ because they’re literally the last step in the process before the motorcycle starts moving. 

The final drive can be a chain as in most motorcycles, a belt as in some cruisers such as Harley Davidsons, or shaft drive, which is also seen in a lot of larger motorcycles. 

We won’t go into too much detail about the different types of final drive setups, but chains are by far the most common one. 

Chains are easy to work on, customize, and offer a great strength-weight ratio. Still, they require a lot of regular maintenance and they can break over time.They are also the component-of-choice for high performance racers and sport bike riders. 

The second most common type of final drive is belt-drive. 

These have the benefit of being quieter than chain drive, while also requiring less adjustment and maintenance. Belts are mostly seen on bikes that are designed for long-haul use, so the cruisers and touring bikes of the world. Maintenance requirements are practically nonexistent. 

However, they aren’t as efficient at transferring power from the engine to the wheels as chains. Furthermore, they aren’t as easy to work on or replace, one the off chance that something goes wrong. 

And finally, we have shaft drive. These setups use a spinning steel rod to transfer power from engine to rear wheel. Shaft drive is even more reliable and long lasting than belt drive. In fact, a shaft drive setup is virtually indestructible. 

The drawbacks of shaft drive include heavier weight, more expensive initial cost, and a complicated design that is harder to work on. 

Still, there is next to no maintenance required, and the most you’ll have to do is replace the fluid in the differential housing every other year.