30Z crown gear bronze insert

The Slot.it 30Z crown gear with bronze insert, a key reference for inline setups

When working on the transmission of a slot car with an inline motor position —that is, with the motor arranged longitudinally, in line with the rear axle— every component of the powertrain matters. This 30-tooth crown gear with a bronze insert from Slot.it meets that requirement exactly: a well-defined piece, with the precise fit that characterises the Italian brand.

Technical specifications

• Number of teeth: 30Z
• Insert: bronze
• Compatible axle diameter: 2.38 mm
• Application: inline motor configuration
• Reference: SIGI30BZ

Function and performance

The bronze insert is one of the most valued details in slot preparation. Bronze offers a combination of controlled hardness and a certain degree of self-lubrication that reduces wear on the axle, extending the lifespan of both the crown gear and the rear axle itself. It is a common choice among preparers looking for a balance between precision and minimal maintenance.

With 30 teeth, this crown gear falls within a moderate-high gear ratio range when combined with pinions of between 9 and 12 teeth, making it versatile for both technical circuits with slow corners and mixed layouts where a good compromise between acceleration and top speed is needed.

Compatibility and installation

It is designed for a rear axle of 2.38 mm, a standard measurement in much of the Sport track chassis (Scaleauto, Slot.it) and also present in numerous universal track preparations (Scalextric, Ninco). Before installation, it is advisable to check that the axle is clean and free of burrs to ensure a perfect fit for the bronze insert.

In an inline configuration, the pinion is placed directly on the motor shaft, which is aligned longitudinally with the rear axle. This allows for a lower centre of gravity compared to other configurations, a highly appreciated aspect in club racing.

Common mistakes to avoid

• Do not force the crown gear onto the axle without first checking the exact diameter: although 2.38 mm is a widely used measurement, small variations can affect the fit.
• Do not overtighten if using retaining glue: the bronze insert already provides a solid grip through friction under normal conditions.
• Check the alignment of the crown gear and pinion after installation to avoid vibrations or premature wear.

Frequently asked questions

What is the difference between a crown gear with a bronze insert and one without?

The bronze insert acts as a bushing between the plastic of the crown gear and the metal axle. It reduces wear from friction, improves torque transmission, and extends the lifespan of the part compared to crown gears made of plastic directly on the axle.

Is it compatible with Slot.it Sport track chassis?

Yes. This crown gear is designed within the Slot.it ecosystem, whose preparations typically work on Sport track. Always check that the axle diameter of your chassis is 2.38 mm.

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

This crown gear is specifically designed for inline configuration. Although it could technically fit in other setups if the pinion module is compatible, Slot.it designs and recommends it for inline use.

What gear ratio do I get with this crown gear?

It depends on the pinion you use. With a 10-tooth pinion, you would achieve a ratio of 3:1; with a 9-tooth pinion, 3.33:1. A higher ratio provides more acceleration but lower top speed, and vice versa.

Does the bronze insert require maintenance?

Bronze has some self-lubricating capability, but a small application of specific slot lubricant at the crown-axle contact point is recommended, especially during long racing sessions.

The Slot.it SIGI30BZ is a 30-tooth inline crown gear with a bronze insert, designed for 2.38 mm axles. A precise and durable slot car transmission component for inline motor setups, compatible with Sport track systems. Ideal for club racing and performance builds where reliability and clean power transfer make the difference.