Wheel Esp. 27.5x13mm. Procomp3 for 3mm Axle. Rim ø21 and M3 Screw.

The Scaleauto SC-2421P features the Procomp3 compound in a ø21mm wheel format for 3mm axles, covering one of the most demanded combinations in the 1/24 category.

Within the Scaleauto spare parts catalogue for wheels and tyres, the reference SC-2421P represents a straightforward and uncompromising option for those looking to mount a complete wheel ready to race. The Procomp3 compound is a technical foam that Scaleauto has specifically developed for competition, with a hardness profile aimed at providing consistent grip and progressive, controlled wear throughout race sessions.

Function and performance

The Procomp3 foam operates within a grip range that makes it particularly effective on lacquered wooden and plastic tracks, the two most common substrates in 1/24 club circuits. Its cellular structure allows for a uniform contact patch that translates into stable grip both on straights and in tight corners, without the traction spikes that can sometimes complicate car balance.

The size of 27.5mm in diameter by 13mm in width is a well-established standard in 1/24 scale, providing an appropriate load distribution for GT and Touring Car bodies without compromising the gear ratio.

Compatibility and mounting

The set is designed for 3mm axles, the most widespread diameter in 1/24 competition chassis. The machined aluminium rim of ø21mm incorporates fixing via M3 screw, ensuring a secure tightening and facilitating disassembly and replacement in the pits without special tools beyond an Allen key.

The wheel-tyre combination comes pre-mounted from the factory, so there is no need to glue or centre the tyre before turning: simply check the centring on the lathe or bench and adjust if necessary before the first session.

Mounting and preparation

• Check the wheel centring on the axle before racing, especially if it has been mounted cold.
• A slight turning on the bench allows for equalising the exact diameter to the desired working size if starting from the nominal diameter of 27.5mm.
• The M3 screw should be tightened with controlled torque to avoid deforming the aluminium rim.
• On high-grip tracks, the Procomp3 can be cleaned with isopropyl alcohol to maintain grip consistency between heats.

Common errors

• Mounting the wheel without checking the centring: although they come pre-mounted, any small misalignment is amplified at 1/24 competition speeds and generates noticeable vibration.
• Over-tightening the M3 screw: this can cause micro-deformations in the rim that affect dynamic balance.
• Confusing the Procomp3 compound with other compounds in the Scaleauto range: each reference has a different hardness and usage profile; it is advisable to consult the complete range before choosing the compound for each type of track.

Frequently asked questions

Is this wheel ready to mount or do I need to glue the tyre to the rim?

The SC-2421P is a complete set with the Procomp3 tyre already mounted on the ø21mm aluminium rim. It does not require prior gluing, although it is recommended to check the centring before the first session.

Which 1/24 chassis is this wheel compatible with?

It is compatible with any 1/24 chassis that uses 3mm diameter axles and provides wheel fixing via M3 screw. Scaleauto designs these sets for its own range of competition chassis, but they can be adapted to other setups with the same axle standard.

Is it necessary to turn the tyre before competing?

It is not strictly necessary, as the nominal diameter of 27.5mm is the working size. However, many preparers perform a slight turning to equalise both wheels on the axle and ensure perfect contact with the track.

How many units does the reference SC-2421P include?

The reference includes 2 units, that is, the wheels for a complete axle.

Is the Procomp3 compound suitable for plastic and wooden tracks?

Yes. The Procomp3 is designed to provide consistent performance on both lacquered wooden and plastic tracks, which are the two predominant surface types in club competition at 1/24 scale.

Can I clean the tyre between heats to regain grip?

Yes. Cleaning with isopropyl alcohol is the usual practice to remove track residue and restore the grip capability of the Procomp3 foam between sessions.

The Scaleauto SC-2421P are complete slot car wheels featuring the Procomp3 foam compound mounted on a ø21mm aluminium rim, designed for 3mm axles with M3 screw fixing. With a 27.5x13mm size, they are a go-to choice for 1/24 scale competition on both wooden and plastic tracks. Ideal for GT and Touring Car categories, these wheels deliver consistent grip and controlled wear, making them a reliable upgrade for club and championship racing in 1/24 slot.