Spring preload refers to the amount of adjusted tension applied to the fork springs and rear shock spring(s). The adjustable preload feature gives the rider the ability to apply more tension to the springs if the ride feels too soft, or less tension if the ride feels too stiff. On most models spring preload is adjustable on either the front forks or the rear shock absorber or both. The springs of the front and rear suspension support the weight of the motorcycle and rider while cushioning the ride as the bike travels over the irregularities in the road or track. Spring rates are based on the type of riding a model is intended for and average rider weight. The preload adjustment provides some variation for rider weight and road and track surface variation.