Decrease shock spring preload. Decrease shock compression damping Install softer spring. Rear shock kicks up during braking. Increase rebound damping. Increase shock rebound damping.
Rear shock feels soft on large bumps or jumps.
Increase shock compression damping. Decrease race sag. Install stiffer spring. Shock made need re-valving. Rear shock feels too hard over jumps, large bumps, or a series of small bumps.