Motorcycle Suspension Terminology Explained | The Shop Manual

Summary

This video provides an in-depth breakdown of motorcycle suspension terminology, helping riders understand crucial concepts like spring rate, preload, sag, and damping. The host explains how suspension components work together to enhance comfort, control, and handling. Key vocabulary terms such as compression, rebound, and the differences between hard/soft and fast/slow settings are explored in detail. By the end, viewers will have a solid understanding of suspension mechanics, ensuring better tuning for a smoother, more comfortable ride.

Takeaways

• 😀 Suspension is crucial for keeping your wheels in contact with the road and protecting your backside and spine from excessive impact.
• 😀 Understanding suspension lingo is essential for adjusting your bike for a comfortable and controlled ride.
• 😀 Spring rate refers to the stiffness of the springs, affecting how much force is required to compress them. It’s essential to match spring rates to your body weight.
• 😀 Spring preload is the amount of compression applied to the spring before any load is added. It affects how much force it takes to initiate suspension movement.
• 😀 Preload helps prevent bottoming out by altering the range of spring stroke used during riding.
• 😀 Sag is the measure of how much suspension compresses under load, with rider sag being particularly important to adjust for comfort and control.
• 😀 Ideal rider sag should be about one-quarter of total suspension travel, with free sag being one-third of rider sag.
• 😀 Damping regulates how quickly suspension compresses or extends, and it’s crucial to prevent suspension from behaving erratically (like a pogo stick).
• 😀 Compression damping slows down suspension movement during compression, while rebound damping controls the rate of extension after compression.
• 😀 Suspension can be described using terms like hard/soft and fast/slow, where 'hard/soft' refers to spring or damping settings, and 'fast/slow' refers to the rate of damping.
• 😀 Mastering suspension lingo, including terms like spring rate, preload, sag, and damping, is key to fine-tuning your suspension for optimal performance and comfort.

Q & A

What is suspension, and why is it important for motorcycles?

Suspension allows the wheels to follow the road, keeping the rider comfortable by isolating the body from road jolts. It also ensures that the wheels maintain proper contact with the road, which is essential for handling and safety.

What does 'spring rate' refer to in suspension terminology?

Spring rate refers to the stiffness of the spring in the suspension system, measured in pounds per inch or kilograms per millimeter. It indicates how much force is required to compress the spring a given distance, helping to ensure the right balance of comfort and control.

How does spring rate affect suspension performance?

The correct spring rate ensures that the suspension is soft enough to absorb bumps but stiff enough to prevent bottoming out and excessive chassis movement during braking and acceleration. If the spring rate is too low or too high for the rider’s weight, it can lead to poor ride quality.

What is spring preload, and how does it affect suspension performance?

Spring preload refers to the amount a spring is compressed from its free length when the suspension is fully extended. It alters how much force is needed to initiate suspension movement and affects the total available range of spring stroke. Preload is mainly used to adjust sag and prevent bottoming out.

What is the difference between 'free sag' and 'rider sag'?

Free sag is the amount the suspension compresses under the weight of the bike alone, while rider sag (laden sag) is how much the suspension compresses with the rider on board, wearing all gear. Rider sag is the more important figure for tuning suspension for optimal comfort and performance.

What is the ideal amount of rider sag for street bikes?

For street bikes, rider sag should be about one-quarter of the total suspension travel. This ensures that the suspension is neither too stiff nor too soft and is able to absorb road dips and bumps effectively.

What is damping in suspension systems, and why is it important?

Damping controls the speed at which suspension components compress and extend. It is essential to prevent the suspension from behaving like a pogo stick, ensuring better control, comfort, and traction. Without damping, the suspension could oscillate uncontrollably after hitting a bump.

What is the difference between compression damping and rebound damping?

Compression damping controls the speed at which the suspension compresses when the bike hits a bump or when load is transferred. Rebound damping, on the other hand, regulates the speed at which the suspension returns to its extended position after compression.

What do the terms 'fast' and 'slow' refer to in suspension settings?

'Fast' and 'slow' describe the speed at which the suspension components move during compression or rebound, not the speed of the rider. A 'fast' setting means the suspension reacts quickly, while a 'slow' setting means the suspension responds more gradually.

How do 'hard' and 'soft' settings affect suspension performance?

'Hard' and 'soft' settings can refer to either the spring rate or the damping settings. A 'hard' setting makes the suspension feel stiffer and less forgiving, while a 'soft' setting allows more movement, providing a smoother ride over bumps. The right balance depends on the rider's weight and riding conditions.