Spring Preload & Ride Height
What Preload Is
- The load on the spring before the vehicle's weight is on it.
- It determines where the shock sits in its stroke.
- It is not the same adjustment as ride height, though on many shocks one control changes both.
Where It Puts the Shock
- More preload — the spring pushes harder, so the shock settles further extended, nearer the end of its rebound travel. Less droop left before it tops out.
- Less preload — the shock settles further compressed, nearer the bump stop. Less compression travel left before it bottoms.
What You Feel
- Topping out — not enough rebound travel, so the chassis falls into undulations in the road.
- Bottoming out — not enough compression travel, so you feel it every time you hit a pothole.
- One spring rate can give two completely different ride qualities depending on where the shock is sitting.
- If the car rides badly on good coilovers, check this before changing spring rates.
Two Types of Shock
- Preload adjustment only. Ride height can only be changed with preload, so the height you want may compromise your shock travel. You are choosing between the two.
- Preload plus a separate length adjuster. The two are independent — set the shock where you want it in its stroke and set ride height separately.
Left to Right
- Uneven preload side to side puts uneven load into the chassis.
- The car will behave differently turning left than right.
- If you are corner weighting, preload is one of the things you are adjusting.
If You Run Out of Adjustment
- Usually means the wrong spring rate or spring length for the height you want.
- Contact us before forcing it.
More detail and photos to follow. If you have a question this does not answer, contact us and we can help guide you.