The following list contains many of the terms you come across when talking about a motocross bike’s suspension systems. For more information on suspension see suspension setup tips.
Acceleration Headshake When the front of the bike starts to shake while accelerating. Not as common as deceleration headshake and generally occurs when existing corners under power or on long straight-aways.
Bottoming When the front or rear suspension systems use ALL available travel to absorb an impact. Forks or shock have completely collapsed.
Compression Means to press or squeeze together. The front and rear suspension systems compress when landing off a jump, hitting a bump, or braking for corners.
Compression Adjuster Used to adjust the front or rear compression setting. The rear compression adjuster is located on the rear shock at the top of the reservoir. The front compression adjuster could be on the top or bottom of the forks depending on your bike. Check your owner’s manual for correct location.
Deceleration Headshake When the front of the bike starts to shake under braking or when you let off on the throttle. Most common form of headshake.
Diving When the forks compress very quickly. Mostly occurs when braking hard for a corner.
Headshake When the front end of the motorcycle oscillates back and forth. Headshake can occur during acceleration or deceleration.
Hopping When the front or rear wheel bounds off the ground when landing from a jump or hitting bumps.
Over Steer When corning, the front end of the bike “washes out” or “knifes inward."
Pogo When the shock or forks rebound so quickly that the rear or front wheel leaves the ground.
Preload Refers to how much tension is applied to a spring. You use preload to adjust the sag. More preload increases the tension on the spring and decreases the sag. Less preload decreases the tension on the spring and increases the sag.
Rebound Means to “spring back.” The front and rear suspension rebound after being compressed from an impact.
Rebound Adjuster Used to adjust the front and rear rebound setting. The rear rebound adjuster is located at the bottom of the shock by the rear shock linkage. The front rebound adjuster could be on the top of bottom of the forks depending on your bike. Check your owner’s manual for correct location.
Revalve Revalving is the process of changing the internal compression and rebound shims to change the flow of oil throughout passages in the front forks and rear shock. A suspension specialist should revalve your bike’s suspension.
Sag Refers to how much the rear suspension compresses when a rider in full gear sits on the bike. Sag is measured in millimeters. For big bikes, 100mm is generally the standard sag setting. For mini bikes, 85 mm is generally the standard sag setting. Check owner’s manual for the manufacture's recommended setting.
Spring Rate Refers to the strength of a spring. Measured in kilograms per millimeter or pounds per inch.
Static Sag Refers to how much the rear suspension sags under only the bike’s weight (no rider aboard).
Swapping When the rear end jumps quickly from one side to the other.
Top Out When the rear shock fully extends.
Under Steer When corning, the front end of the bike refuses to turn or turns outward.
Unstableness When the bike feels uncontrolled, unpredictable and inconsistent. The bike does not feel steady or balanced. The front and rear are not working together.
Washes Out Front end of the motorcycle turns inward, especially when cornering. Same as Over Steer.