UNIVERSAL spring for suspension L7/3-S20

The soft spring that makes a difference in tuning your slot suspension

When working on the suspension of a slot car, choosing the right spring is not a minor detail: the hardness and length of the spring define how the chassis absorbs track irregularities, how the load is distributed over the tyres, and ultimately, how much real grip is achieved in corners. The UNIVERSAL Spring for L7/3-S20 Suspension from Sloting Plus (reference SP117023) is designed for those who approach the preparation of their car with technical criteria.

Main features

• Material: stainless steel, resistant to corrosion and fatigue from repeated compression cycles.
• Inner diameter: 3 mm.
• Length: 7 mm.
• Hardness: SOFT — ideal for configurations that prioritise constant tyre contact with the track on surfaces with variations or technical profiles.
• Contents: pack of 6 units.
• Compatibility: universal, suitable for various suspension systems in prepared slot cars.

Function and performance

A soft spring allows the suspension to work with greater travel over the same irregularities, keeping the tyres in contact with the track for longer. This translates into more stable driving on tracks with profile variations, greater consistency in corners, and better power transmission to the ground. The S20 hardness of this reference places it in the soft range of the Sloting Plus catalogue, designed for setups where a smooth response is sought over rigidity.

Compatibilities and installation

Its condition as a universal spring makes it compatible with the most common suspension systems in prepared slot cars that accept springs with a 3 mm inner diameter. Before installation, check that the spring housing in your chassis accommodates this measurement and that the 7 mm length fits the desired suspension travel. If you seek a firmer response, Sloting Plus offers equivalent springs in higher hardnesses for comparison and fine-tuning the setup.

Common mistakes when choosing a suspension spring

• Confusing inner diameter with outer diameter: always check the full reference before ordering.
• Using a spring that is too stiff on tracks with a lot of profile: the car loses contact and grip falls. For those conditions, a soft spring like this is the right choice.
• Not replacing the spring after many sessions: stainless steel holds up well, but any spring subjected to intense compression eventually fatigues. Having 6 units in a pack allows for replacement without waiting for a new order.

Ideal for…

Preparers and club drivers who work on their slot cars with dedication, looking to fine-tune track behaviour and wanting to have a stock of suspension consumables to keep the workshop running. It is also practical for those testing different spring hardnesses and needing several identical units for controlled comparison.

Frequently asked questions

What does the designation L7/3-S20 mean?

The nomenclature indicates the characteristics of the spring: L7 refers to the length of 7 mm, /3 to the inner diameter of 3 mm, and S20 to the soft hardness (S for soft) on the Sloting Plus scale.

Which suspension systems is it compatible with?

It is a universal specification spring valid for slot suspension systems that use springs with a 3 mm inner diameter. Check the measurements of your chassis before installation to confirm exact compatibility.

How many units does the pack include?

Each pack contains 6 identical springs, allowing for spare availability for several preparation sessions or to equip more than one car.

When is it advisable to use a soft spring versus a stiffer one?

The soft spring is recommended when the track presents irregularities, profile variations, or surfaces where constant tyre contact is a priority. A stiffer spring provides greater stability on smooth, fast tracks where minimising chassis movement is sought.

Does stainless steel offer advantages over other materials?

Yes: stainless steel is more resistant to oxidation from environmental moisture or frequent handling, and maintains its elastic properties better after many compression cycles compared to untreated carbon steel.

The Sloting Plus SP117023 is a universal soft suspension spring for slot car preparation, featuring a 3 mm inner diameter and 7 mm length, made from stainless steel. Sold in a pack of 6 units, it is compatible with the most common slot car suspension systems and is ideal for setups requiring smooth, consistent tyre contact on technical or uneven track surfaces. A must-have consumable for club racers and serious slot car builders looking to fine-tune their chassis behaviour.