Rubber Tyre 20x12mm New Shore 30 for Wheels ø15/17mm.

Scaleauto Rear Tyres in Soft Compound for Maximum Track Performance

When it comes to fine-tuning the performance on the rear axle of a 1/32 slot car, the choice of tyre is one of the most important decisions we make in the preparation bench. These Scaleauto SC-4721SH30 rubber tyres combine a specific size of 20x12mm with a Shore hardness of 30 —soft compound— to provide a generous contact patch and progressive grip from the start.

Function and Performance

The Shore hardness of 30 places these tyres in the soft range of the Scaleauto catalogue. A softer compound slightly deforms under load, increasing the contact surface with the track and translating that deformation into real traction. The result is a cleaner corner exit and greater stability on fast sections, especially on plastic or resin tracks where natural grip is more demanding.

The size 20x12mm is suitable for rear configurations of GT and touring cars in 1/32 scale, where a generous profile is sought without compromising chassis height.

Compatibility

These tyres are designed to fit on ø15mm and ø17mm rims, two of the most common diameters in the Scaleauto universe and much of the 1/32 spare parts market. It is advisable to always check the exact size of the rims installed on the car before proceeding with the fitting, to ensure a correct fit and avoid unwanted stresses on the rubber.

Fitting and Preparation

• Before fitting, clean the rims with a dry cloth to remove any grease or dust that may compromise the tyre adhesion.
• Stretch the tyre evenly around the rim, starting from one side and working symmetrically to avoid deformations.
• Once fitted, truing is the best way to ensure a perfectly concentric circumference, especially in club or federated competition.
• Store any leftover tyres in a cool place away from direct light to preserve the properties of the compound.

Common Mistakes

• Mixing hardness on the same axle: always use tyres of the same Shore on both rear wheels to maintain the car's symmetrical behaviour.
• Not truing after fitting: even with new tyres, it is common to have slight eccentricities. Truing eliminates vibrations and improves contact.
• Ignoring rim diameter: fitting a tyre on a rim outside the indicated tolerance (ø15/17mm) can deform the profile and alter the car's height.

Ideal for…

Club competitors looking for a reliable soft compound for indoor tracks, preparers who want to always have a spare set on hand, and enthusiasts who are taking their first steps in tuning the rear axle. The pack includes 4 units, enough to equip a complete car and maintain another set in reserve.

Frequently Asked Questions

What does Shore 30 mean in a slot tyre?

Shore is the scale that measures the hardness of elastomers. A value of 30 indicates a relatively soft compound, which deforms more under load and offers greater grip, at the cost of slightly faster wear than harder compounds.

How many units are included in this pack?

The pack contains 4 units, sufficient to equip the rear axle of a 1/32 slot car with an additional spare pair.

Are they compatible with rims from other brands?

Compatibility is indicated for rims of ø15mm and ø17mm. As long as a rim from another brand respects those diameters and its width is compatible with the 12mm of the tyre, the fitting should work correctly. Still, we recommend verifying the measurements before fitting.

Do I need to true these tyres before using them on track?

It is not strictly mandatory for recreational use, but it is highly recommended in competition. Truing ensures that all tyres are at the same height and eliminates any eccentricity from the fitting, resulting in a more stable and predictable car.

How should I store the tyres that I do not use?

Store them in a sealed bag, in a cool, dry place away from direct sunlight and sources of ozone (electric motors, fluorescent lights). Heat and light degrade the compound and reduce its elasticity over time.

Scaleauto SC-4721SH30 slot car tyres, 20x12mm soft compound Shore 30, compatible with ø15mm and ø17mm rims for 1/32 scale rear axle. Four-piece pack ideal for club racing and track preparation. Available at Ministry of Hobby, your specialist in slot car parts and accessories.