4 Classic Tyres 21x6 Smooth

Classic tyres 21x6 smooth: the foundation of a good slot setup

The tyre is one of the elements that most influences the behaviour of a slot car, and it is often the first component that the preparer checks when something is off. These classic tyres with a size of 21x6 and smooth profile come in a pack of 4 units, covering all four wheels of the car in a single purchase and ensuring uniformity among the four contact points with the track.

Product features

• Size: 21x6 mm (diameter x width)
• Profile: smooth, no tread
• Contents: 4 tyres per pack
• Reference: CXM071
• Type: classic tyre

Function and performance

The smooth profile offers the largest possible contact surface with the rail, resulting in homogeneous grip and controlled sliding. It is the usual choice on wooden tracks or smooth surfaces, where tread on the tyre does not provide an advantage and can even hinder stability.

The size 21x6 is one of the most common in the classic slot world and fits a wide variety of standard wheels. Keeping all four tyres in good condition and with the same actual diameter is essential for the car to run straight and respond predictably to directional changes.

Installation and preparation

Before mounting the tyres, it is advisable to clean the wheels of any adhesive or previous rubber residue. Once fitted, it is recommended to lightly turn the tyres on a slot lathe to equalise the exact diameter of all four and correct any possible eccentricities. This step makes a noticeable difference in stability, especially on high-speed straights.

If they are to be glued, a minimal amount of glue on the inner area of the tyre is sufficient, ensuring it does not protrude onto the sides.

Ideal for…

• Preparers looking to replace all four tyres at once while maintaining uniformity.
• Club racing on smooth or wooden tracks.
• Classic builds where stability is prioritised over aggressive grip.
• Enthusiasts wanting to have spare tyres on hand to avoid interrupting sessions.

Considerations

Always check that the inner diameter of the tyre is compatible with the outer diameter of the wheel you are using. The size 21x6 is indicative of the unmounted tyre; once on the wheel, the effective diameter may vary slightly depending on the fit. Subsequent turning ensures the desired final measurement.

Frequently asked questions

How many tyres are included in this pack?

The pack contains 4 tyres, sufficient to equip all four wheels of a slot car.

What advantage does the smooth profile have over the treaded one?

The smooth profile maximises the contact surface with the track, providing more uniform grip. It is the most common option on smooth or wooden tracks, where tread does not offer tactical benefit.

Is it necessary to turn these tyres before using them?

It is not strictly mandatory, but it is highly recommended. Turning equalises the actual diameter of all four tyres and eliminates eccentricities, significantly improving the car's stability on track.

What track systems are these tyres compatible with?

Compatibility depends on the car's wheels, not the track system. Ensure that the inner diameter of the tyre fits the outer diameter of your wheels before mounting.

Can they be used in official competition?

It depends on the specific regulations of each championship or club. We recommend checking the rules of your category before using them in federated competition.

Classic slot tyres 21x6 smooth profile, set of 4 units (ref. CXM071). Ideal for slot car preparation, club racing and classic slot builds on wood or smooth tracks. Standard 21x6 sizing fits a wide range of classic slot car wheels. Smooth tyre for consistent grip and predictable handling.