5 Modifications to Increase a Motorcycle’s Speed

Whether it is a CRUISER, SPORTS bike, naked bike, DIRT bike, or touring bike, almost every rider wants to boost performance and increase the top speed without damaging the engine. Luckily, anyone can easily improve a motorcycle’s performance and speed by implementing the right modifications. The modifications discussed in this article can be implemented separately or simultaneously.

A lot of riders rely on mechanics to modify their motorbikes. However, it is possible for a knowledgeable rider who understands motorcycles and how to use tools to apply modifications themselves. As each modification has its pros and cons, it is best that riders understand the changes each modification has.

One of the most basic ways to increase a motorcycle’s speed is by reducing its overall weight. The motorcycle’s weight is inversely proportional to its speed and efficiency. The heavier a motorcycle is, the more power the engine must produce to be able to move the vehicle. By reducing the weight, a rider can improve handling and speed. Removing the following parts from the motorcycle can help reduce the motorcycle’s overall weight:

Fenders protect the rider and the upper body of the motorcycle from being splattered by mud. However, some motorcycles, mostly cruisers, and touring bikes have heavy fenders. Riders can either remove these fenders or replace them with lighter aftermarket fenders to reduce weight.

Cruiser, touring bikes, and sports motorcycles can be fitted with different types of FAIRINGS. Fairings on sports motorcycles are mostly lightweight, reduce air drag, and have good aerodynamics. On the other hand, cruisers and touring motorcycles have heavy and bulky fairings that look beautiful but lack good aerodynamics. Removing heavy fairings or replacing them with lightweight fairings can reduce weight.

Lighter tires offer good wheel travel when connected to suspensions that can handle bumpy terrain. For example, dirt motorcycles have light, sleek tires with less surface area, hence requiring less engine power, increasing fuel economy, and improving handling.

Because of lighter tires, if the motorcycle hits a bump at a higher speed there is a high chance that the rim may face a bend. Sleeker tires have less surface area and traction, therefore, more chances of slipping at high speed.

Mostly naked, cruiser, and touring motorcycles have bulky or dual SEATS that ensure soft and comfortable rides. Depending on the riders, they can change the dual seat with a solo seat instead. As a solo seat is more compact, this also helps reduce the motorcycle’s weight.

SADDLEBAGS, CRASH BARS, SISSY BARS, windshields, etc. add extra weight, so removing these parts will significantly reduce a motorcycle’s overall weight.

Increasing horsepower can also help increase a motorcycle’s speed. Speed is directly proportional to the rpm and horsepower. To increase the horsepower, you would have to modify the engine.

If the engine has a higher air intake, combustion will occur faster and the engine will rev up more quickly. Air intake can be increased by simply upgrading the air filter with a bigger version.

Increasing air intake not only increases horsepower but can also damage the engine if the fuel and air ratio is off-balance. If the engine takes in more air, it will also require more fuel for combustion to occur. If the fuel and air ratio is not maintained, the engine risks overheating and engine seizure.

If the engine has a high air intake but cannot properly emit fumes from the exhaust pipes, the engine cannot deliver adequate power. Therefore, changing the exhaust system may also be required. The pre-installed exhausts have mufflers that make it difficult to freely emit air. To improve airflow, it is recommended you change the exhaust system and air filter(s).

Replacing the stock heavy exhausts with lighter aftermarket exhausts reduces weight. Try to pick quality aftermarket exhausts with mufflers close to the pipes to improve airflow.

There is a risk of aftermarket exhausts being of poor quality, increasing air resistance reducing power output, or causing the engine to overheat.

There are two types of fuel control systems in motorcycles. The CDI (Capacitor Discharge Ignition) controls the amount of voltage directed to the ignition, igniting the fuel in the engine.

The ECU (Engine Control Unit) is used in motorcycles with a fuel injection system, which monitors rpm and speed, and controls the fuel pump. You can increase the ECU’s output by changing the ECU’s settings or switching out for a quality aftermarket ECU.

Changing the ECU or its setting will increase the overall speed at different rpm. The fuel pump will be able to keep up and provide the required fuel to the engine even at higher rpm.

Companies set a speed limit at specific rpms so that motorcycles will last longer and improve performance. Changing these fuel control settings means the engine can now exceed the safety limits. However, doing so can drastically shorten the engine’s lifespan if it is not regularly maintained.

One of the easiest and cheapest ways to increase speed is by changing out the sprockets. This method can only be implemented on motorcycles with a belt or chain drive train. These motorcycles have one small sprocket attached to the output shaft (countershaft) at the engine side while the big sprocket is attached to the rear wheel. The sprocket attached to the output shaft is smaller and has fewer teeth than the sprocket on the rear wheel.

Increasing the size or number of teeth on the output shaft sprocket or decreasing the size or number of teeth on the rear wheel sprocket helps the motorcycle travel at a higher speed at the cost of less acceleration. On the other hand, decreasing the size or number of teeth on the output shaft smaller sprocket or increasing the size or number of teeth on the rear wheel sprocket improves acceleration at the cost of less speed.

Increasing the output shaft sprocket’s size will improve speed but have less acceleration which will put stress on the engine. Increasing the size of the smaller sprocket also increases the tension in the chain/belt and reduces the overall life of the drivetrain.

Modifying the engine is the most expensive and risky method but can yield impressive results Modifying the engine means changing the engine’s stroke and bore size.

Most sports motorcycles have a bigger bore size than stroke size. Therefore, they can produce more horsepower and less torque than cruisers and touring motorcycles. Meanwhile, cruisers and touring motorcycle engines have bigger stroke sizes than bore sizes. Therefore, they can produce more torque but less horsepower than sports motorcycles.

By increasing the bore size and decreasing stroke size, the engine will have better fuel combustion, larger valve openings, and a shorter piston. This will ensure shorter wheel travel, increased speed, and increased horsepower. With a bigger bore and a smaller stroke, the engine can rev faster and generate more horsepower.

Increasing the bore size and decreasing the stroke size reduces wheel travel during combustion and reduces fuel economy. An engine with a bigger bore and smaller stroke does not perform as well at lower rpm.

The type of fuel can also affect a motorcycle’s performance. The higher the octane value of the fuel, the better combustion will occur in the engine. Low-octane fuel can cause knocking in the engine.

Knocking refers to premature combustion in the engine that causes stiff piston movements. Knocking can disrupt the overall performance of the engine as the throttle may not be as responsive. High-octane fuel will help reduce knocking in the engine.

However, high-octane fuel is not recommended for every motorcycle. It is mostly used for high-performance or supercharged engines. Long exposure to lower-octane fuel in such engines can damage the emission control system due to knocking.

Always use highly synthetic oil if the engine had its sprockets, bore size, stroke size, or fuel control system modified. Due to the rpm and speed limits being exceeded, the engine needs the best quality engine oil to ensure it works properly and has stable performance. Otherwise, the engine will overheat and its parts will wear out more quickly.

Research every aftermarket part that you want to install. Read the instructions from standard and aftermarket part manuals to check whether the parts are compatible with your motorcycle.

The safest way to increase your motorcycle’s speed is to reduce its overall weight, replace the stock motorcycle parts with lightweight aftermarket parts, or upgrade the air filter and exhaust system. Changing out the sprockets are easy modification but can put a load on the engine if it is not well-maintained. Changing the ECU or its setting can improve efficiency when producing power, but can be dangerous for the engine if the fuel pump is not properly tuned or the air intake/release is not properly balanced. Modifying the engine’s bore and stroke sizes is the riskiest way to increase speed since changing an engine’s design can be costly and requires proper research about the final outcome and dangers.