24Z crown gear aluminium insert

The lightest inline crown gear from Slot.it for those who fine-tune every tenth

The SIGI24AL is the aluminium-bodied version of the 24-tooth inline crown gear from Slot.it. Within the range of 1/32 spare parts from the Italian brand, this reference holds a prominent place for tuners and drivers looking to extract the maximum performance from their transmission without compromising reliability.

Function and performance

The purpose of an inline crown gear is to transmit the rotation of the motor — positioned longitudinally, in line with the chassis — to the rear axle. Reducing the mass of this component has a direct and measurable effect: the motor accelerates with less effort, the RPM rises faster, and when the trigger is pulled, the engine brake acts more forcefully. On a circuit with many chicanes or slow corners, that difference is noticeable lap after lap.

With a weight of 1.1 g and an outer diameter of 13.9 mm, the SIGI24AL is one of the lightest crown gears available in module 50. The machined aluminium allows for this weight while maintaining the necessary rigidity to withstand the transmission stresses during long competition sessions.

Compatibility and mounting

This crown gear is designed for 3/32" (2.38 mm) axles and is secured using an M2 grub screw, a standard system in the Slot.it range. Its module 50 makes it compatible with the brand's pinion family, ensuring smooth engagement with minimal play when the mesh is properly adjusted.

The reduced diameter of 13.9 mm is particularly useful in bodies with narrow wheel arches or in chassis where a larger diameter crown gear could interfere with the body or suspension springs.

Installation and preparation

• Before installing, check the condition of the pinion: an aluminium crown gear in contact with a worn pinion will accelerate the wear of both parts.
• Adjust the pinion-crown gear mesh with the minimum possible play without tension. Using a cigarette paper as a reference between teeth is a common practice among tuners.
• Apply a minimal amount of specific lubricant for slot transmissions; excess attracts dirt and can affect the grip of the rear tyres.
• Firmly tighten the M2 grub screw but do not overtighten: aluminium is softer than technical plastic and can be damaged with excessive torque.

Common mistakes

• Combining aluminium crown gears with worn plastic pinions. Aluminium holds up well, but a damaged pinion transmits impacts that ultimately damage the teeth.
• Not checking the mesh after a crash. Any lateral impact can shift the crown gear on the axle; it is advisable to check it after a heavy accident during a race.
• Forgetting that diameter affects the gear ratio. When switching from a crown gear with a higher tooth count to this 24Z, the final ratio changes and it may be necessary to readjust the pinion to maintain the desired speed-acceleration balance.

Frequently asked questions

What is the difference between an aluminium crown gear and a technical plastic one?

Machined aluminium offers less mass and greater dimensional rigidity. This translates to lower rotational inertia and better engine braking response. The downside is that it requires more careful adjustment of the mesh and regular lubrication to avoid premature wear.

Is it compatible with chassis from other brands that use 3/32" axles?

In principle, yes, as long as the chassis uses 3/32" (2.38 mm) axles and module 50 pinions. However, Slot.it designs and validates its crown gears for its own range of chassis and pinions, so the optimal combination is achieved within the brand's ecosystem.

Which Slot.it pinions is this crown gear compatible with?

With the entire range of module 50 pinions from Slot.it. The choice of the number of teeth on the pinion will depend on the gear ratio you are looking for based on the motor and the circuit.

For what type of circuit is a 24-tooth crown gear most advantageous?

The 24 teeth offer a balance between acceleration and top speed. In technical and twisty circuits, where exit acceleration from corners is critical, this configuration usually performs well when combined with a smaller pinion.

Does it require specific maintenance because it is aluminium?

Yes. Aluminium is more susceptible to wear from dry friction than some technical plastics. It is advisable to periodically lubricate the transmission and check the condition of the teeth after long racing sessions, especially if the mesh is not perfectly adjusted.

The Slot.it SIGI24AL is a 24-tooth inline crown gear machined from aluminium, weighing just 1.1 g with a 13.9 mm outer diameter. Designed for 3/32" axles with M2 grub screw fixing and module 50 compatibility, it delivers reduced rotational inertia for faster acceleration and sharper engine braking in 1/32 slot car competition. An essential upgrade for serious club racers and setup-focused hobbyists looking to fine-tune their inline drivetrain.