Yes, reducing preload on a motorcycle's suspension can make it feel more harsh. Preload refers to the amount of tension or compression applied to the suspension springs before the weight of the rider and other loads are added. By adjusting the preload, you can set the suspension to be more or less stiff.
When you decrease the preload, you are effectively loosening the suspension, allowing it to compress more easily. This can result in a softer and more comfortable ride over bumps and uneven surfaces. However, reducing the preload too much can lead to excessive sag and bottoming out, where the suspension fully compresses and reaches its limit.
Conversely, if you increase the preload, the suspension becomes stiffer and more resistant to compression. This can enhance the bike's handling and stability, especially during aggressive cornering or braking. However, excessive preload can make the ride feel harsher, transmitting more vibrations and impacts from the road surface to the rider.
Finding the right preload setting depends on factors such as rider weight, riding style, road conditions, and personal preference. It's important to strike a balance between comfort and performance. Adjusting preload is often done in conjunction with other suspension settings, such as damping, to achieve an optimal setup that suits your needs. It's recommended to consult your motorcycle's owner's manual or seek advice from a professional technician for guidance on suspension adjustments.