30d Crown Gear. In-Line Modular for Axles 2.38mm

The modular inline crown gear from Slot.it for 2.38 mm axles that takes care of every detail of your transmission

The reference SIGM30I is the modular inline crown gear from Slot.it with 30 teeth, specifically designed for setups in inline configuration — inline motor with the rear axle — on 2.38 mm axles. Its two-piece construction greatly facilitates assembly and disassembly without the need to completely disassemble the axle, something that club preparers particularly appreciate during quick adjustment sessions.

Features and function

• Number of teeth: 30
• Configuration: Inline (inline motor with the rear axle)
• Modular design: two-piece crown for easy mounting and replacement
• Axle diameter: 2.38 mm
• Contents: 1 crown + 3 shims of 0.1 mm

Compatibility

This crown is compatible with two different pinion configurations, depending on the adapter used:

• Pinions of 5.5 mm using the SIGMF55 adapter (not included).
• Pinions of 6 mm using the GMF60 adapter (not included).

It is important to acquire the corresponding adapter according to the pinion of your motorisation to ensure correct alignment and avoid premature wear in the transmission.

Assembly and preparation

The included 3 shims of 0.1 mm allow for precise adjustment of the lateral play of the crown in relation to the pinion. A correct fit — neither too tight nor excessively loose — is key to achieving a smooth, quiet, and durable transmission. The modular nature of the crown allows it to be changed without disassembling the axle assembly, which reduces preparation time between heats or test sessions.

Common mistakes

• Not using an adapter: Mounting the crown without the appropriate adapter compromises the alignment of the pinion and causes uneven wear.
• Ignoring the shims: Skipping the adjustment with shims can lead to vibrations and loss of power in the transmission.
• Confusing the configuration: This crown is specific for inline setups; it is not interchangeable with sidewinder or anglewinder crowns without verifying the chassis geometry.

Ideal for…

Enthusiasts and competitors who mount or prepare Slot.it cars with inline motorisation and seek a modular crown of proven quality. It is also an interesting option for those who wish to change gear ratios quickly and without additional tools between sessions.

Frequently asked questions

What is the difference between an inline crown and a sidewinder crown?

The inline crown is used when the motor is placed in line with the rear axle (longitudinally). The sidewinder crown corresponds to the configuration where the motor is parallel to the axle, that is, transverse. Using the wrong crown for each configuration causes alignment issues and wear.

Is the adapter included in this reference?

No. The SIGMF55 adapters (for 5.5 mm pinions) and GMF60 (for 6 mm pinions) are not included and must be purchased separately. It is essential to have the correct adapter for mounting.

What are the included 0.1 mm shims for?

They allow for precise adjustment of the lateral position of the crown on the axle, regulating the play in relation to the pinion. Proper adjustment improves the smoothness of the transmission and extends the lifespan of both parts.

Is this crown compatible with chassis from other brands?

It can be as long as the chassis is designed for inline motorisation and uses 2.38 mm axles. However, always check the chassis geometry and the type of pinion before assuming direct compatibility.

How many teeth does this crown have and how does it affect performance?

This crown has 30 teeth. A crown with more teeth, combined with a small pinion, offers higher top speed but less acceleration. Adjusting the crown/pinion ratio is one of the basic tuning tools to adapt the car to each track.

The Slot.it SIGM30I is a 30-tooth modular inline crown gear for 2.38 mm axles, designed for inline motor configurations in 1/32 slot car racing. Its two-piece modular construction allows quick gear changes without full axle disassembly. Compatible with 5.5 mm pinions using the SIGMF55 adapter or 6 mm pinions with the GMF60 adapter (both sold separately). Includes three 0.1 mm shims for precise lateral adjustment. A reliable choice for club racers and hobbyists looking to fine-tune their slot car transmission setup.