Shock springs are one of the most commonly-used tuning options for RC cars. Most cars have a selection of alternate springs, from a couple to a few dozen!
The springs you choose for your car will usually have a different stiffness rating in the front and the rear, particularly for off-road cars. For on-road cars, all 4 springs will often have the same length, but for off-road the rear springs are usually longer.
Also see our article on damping to learn how shock oil and pistons affect handling.
Front springs
Lighter front springs
- More chassis roll / traction
- Less responsive
- Better handling of bumps
Stiffer front springs
- More responsive
- More corner speed if traction allows
- Less chassis roll / traction
- Better jumping and landing
- Ideal for high-grip tracks
Rear springs
Lighter rear springs
- More chassis roll / traction
- More traction
- Less responsive
- Better handling of bumps
Stiffer rear springs
- More responsive
- More corner speed if traction allows
- Less chassis roll / traction
- Better jumping and landing
Center springs (pan car)
Lighter center spring
- Car takes longer to come back to ride height after bumps
Stiffer center spring
- Car stabilizes more quickly after bumps
Side springs (pan car)
Lighter side springs
- More chassis roll
- More consistent on bumpy tracks
Stiffer side springs
- Less chassis roll
- More stable on smooth surfaces
Note that the shock collar (upper spring limiter which sets the spring's pre-load,) should only be used to change the car’s ride height - adjusting it will not change the stiffness of the spring. If you want to change the spring stiffness, you need to change the spring itself.
Spring types
Some manufacturers offer different types of springs with unique qualities that can help under specific track conditions.
Low frequency
Low frequency springs have a higher coil count and less progressive (more linear) feel, i.e. their resistance does not increase as quickly as they compress. They reduce chassis oscillation on rough surfaces, improving overall stability, grip, and corner speed.
Progressive
Progressive springs actually change their spring constant (resistance) based on how far they've been compressed. This allows the car to be free and responsive under normal driving conditions, but in hard corners or over large bumps the springs will resist more and help the car stay stable.
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