CFBikes
Documentation

Suspension glossary

The key suspension terms used across the calculator and the manuals, explained in plain language.

Suspension terms, defined

Definitions
SAG
Amount the suspension compresses under static weight. Free sag (unloaded bike): 0–10 mm — verifies the spring rate is appropriate. Rider sag (rider aboard in riding gear): 25–40 mm depending on riding style — adjusted by turning the spring preload. Correct sag keeps the chassis geometry balanced and ensures full suspension travel is available.
Spring preload
Sets initial spring tension. More preload raises the bike and stiffens early travel — suitable for heavier loads. Less preload lowers the bike and softens the first millimetres of travel. Depending on the adjuster it is set either in turns of a threaded collar, or in steps of a stepped (cam) collar moved with a hook spanner — in that case "position 3" means the 3rd step from the softest setting, not three full turns.
Compression
Controls how quickly the suspension compresses under a bump. More clicks = slower, firmer compression — limits dive under braking but can feel harsh. Less clicks = softer, more reactive fork or shock. Measured in clicks.
Rebound
Controls how quickly the suspension returns to neutral after being compressed. Too fast: bounces back before the wheel settles — chattering. Too slow: suspension stays compressed, packing down and losing grip. Measured in clicks.