28Z crown gear aluminium insert

Slot.it 28Z Crown Gear with Aluminium Insert for Inline Motor: Precision Transmission for Sport Track

The 28Z Crown Gear with Aluminium Insert (SIGI28-AL) is one of the key components in preparing any slot car aimed at competition. Manufactured by Slot.it, a leading brand in the high-performance slot racing world, this crown gear is designed for inline setups — that is, with the motor oriented longitudinally, in line with the rear axle — allowing for a lower centre of gravity and improved cornering stability.

Technical Specifications

• Number of Teeth: 28Z
• Insert: aluminium
• Compatible Axle Diameter: 2.38 mm
• Mounting Type: inline motor (longitudinal)
• Brand: Slot.it
• Reference: SIGI28-AL

Function and Performance

The aluminium insert is one of the details that makes a difference in this crown gear. Aluminium provides a firmer and more uniform grip on the axle than other materials, reducing the risk of slipping under load and contributing to a cleaner transmission of power from the motor to the wheel. In competition, where lap times are measured to the millisecond, these types of construction details have a real impact.

With 28 teeth, this crown gear is part of the most common gear ratios in inline configurations for Sport track. Combined with the appropriate pinion, it allows for adjusting the gear ratio according to the type of circuit: more teeth for fast and flowing circuits, shorter combinations for technical circuits with many curves.

Compatibility and Installation

Designed for a 2.38 mm axle, a standard measurement in most Slot.it kits and chassis. It fits directly into the inline mounts specific to the brand, although it can also be integrated into chassis from other manufacturers that use the same axle diameter and compatible transmission geometry.

The installation is straightforward if you have the appropriate adjustment tools: once positioned on the axle, it is securely fixed thanks to the aluminium insert, which ensures concentricity and prevents vibrations caused by poor fixation.

Common Mistakes

• Not checking the crown-pinion alignment: poor lateral alignment between the two parts causes premature wear and noise. Always ensure that the teeth of the crown and pinion are perfectly aligned.
• Confusing inline geometry with sidewinder or anglewinder: this crown gear is designed for inline setups (longitudinal motor). Do not use it in sidewinder or anglewinder configurations without verifying the compatibility of the tooth profile and geometry.
• Over-tightening the insert on the axle: aluminium is strong, but excessive pressure can deform the insert. Follow the torque specifications recommended by Slot.it.

Frequently Asked Questions

What is the difference between a crown gear with an aluminium insert and a standard plastic one?

The aluminium insert provides a stiffer and more precise grip on the axle, minimising slipping and play that can occur with continued use. In competition, this translates to a more direct and consistent power transmission throughout the session.

Is this crown gear compatible with chassis from other brands?

Yes, as long as the rear axle is 2.38 mm and the transmission geometry is compatible with the tooth profile of the crown. It is a widely used standard measurement in competitive slot racing, although it is advisable to check the centre distance with the pinion you are using.

Which Slot.it pinions work best with this 28-tooth crown gear?

Slot.it offers a wide range of pinions for different gear ratios. The choice depends on the circuit and the motor used. For fast circuits, longer ratios (pinions with more teeth) are usually sought, while for technical circuits, the ratio is shortened. Consult Slot.it's gear ratio tables to fine-tune your setup.

Can I use this crown gear in a sidewinder or anglewinder setup?

This crown gear is designed for inline setups. While the tooth profile may be physically compatible, the transmission geometry and working angle are different in each configuration. Always verify compatibility before installing it in a different setup.

How often should I check or replace the crown gear?

It depends on usage and the level of competition. In recreational use, it can last many sessions without issues. In intense competition, it is advisable to periodically check the condition of the teeth and the fixation to the axle, especially if vibrations or loss of traction are detected.

The Slot.it SIGI28-AL is a 28-tooth inline crown gear with an aluminium insert, designed for 2.38 mm axles and high-performance slot car setups. Compatible with Slot.it inline motor configurations and Sport track systems, it delivers precise power transmission and reliable grip for club racing and competitive use. An essential upgrade for any serious slot car enthusiast looking to fine-tune gear ratios and improve drivetrain efficiency.