29d Crown Gear. In-Line Modular for Axles 2.38mm

The Slot.it modular crown gear for precision inline configurations

The 29-tooth In-Line Modular Crown for 2.38 mm Axles (ref. SIGM29I) from Slot.it is a transmission component specifically designed for inline setups — that is, with the motor aligned with the rear axle in a longitudinal manner — a configuration highly valued by those looking to lower the car's centre of gravity and improve cornering performance.

Main features

• Number of teeth: 29
• Compatible axle diameter: 2.38 mm
• Two-piece modular design: facilitates installation, adjustment, and interchange without the need to dismantle the entire drivetrain
• Contents: 1 crown + 3 shims of 0.1 mm for axial positioning adjustment

Compatibility

This crown is designed to work with two sizes of pinion, depending on the hub used:

• Pinions of 5.5 mm → requires the SIGMF55 hub (not included)
• Pinions of 6 mm → requires the GMF60 hub (not included)

It is essential to have the correct hub to ensure proper alignment between crown and pinion, avoid vibrations, and prolong the lifespan of both components.

Assembly and preparation

The two-piece modular system from Slot.it is one of the most widely used solutions among club preparers and enthusiasts who regularly tune their cars. It allows for the installation or change of the crown without the need to remove the axle, greatly speeding up bench work. The three included 0.1 mm shims are used to fine-tune the lateral position of the crown and achieve a clean and snug engagement with the pinion.

Before assembly, it is advisable to check that the axle is free of burrs and that the chosen hub fits correctly with the pinion to be used. A careless adjustment can lead to noise, premature wear, or loss of performance on track.

Ideal for…

• Preparers working with Slot.it chassis in inline configuration
• Enthusiasts who want to explore different gear ratios without investing in multiple fixed sets
• Club competitors who need to change the crown quickly between sessions without specific tools

Frequently asked questions

Does the crown include the hub?

No. The hub must be purchased separately: the SIGMF55 for 5.5 mm pinions or the GMF60 for 6 mm pinions. Without the correct hub, it is not possible to mount the crown correctly.

What is the difference between a modular crown and a one-piece crown?

The two-piece modular crown can be installed and removed from the axle without completely disassembling it, which is very practical for quickly changing gear ratios. One-piece crowns tend to be stiffer but require more work during the change process.

What are the included 0.1 mm shims for?

They allow for precise adjustment of the lateral position of the crown on the axle, ensuring that the engagement with the pinion is correct and well-centred. The number of shims to use depends on the available space in each chassis.

Is it compatible with axles of other sizes?

This crown is specifically designed for 2.38 mm axles. For other axle diameters, Slot.it has specific references in its transmission catalogue.

Can it be used in sidewinder or anglewinder configurations?

No. This reference is specific for inline setups (longitudinal motor aligned with the rear axle). For sidewinder or anglewinder configurations, there are crowns with geometry and tooth angle adapted to that arrangement.

The Slot.it SIGM29I is a 29-tooth inline modular crown gear for 2.38 mm axles, designed for inline motor configurations in 1/32 slot car racing. Its two-piece modular system allows fast crown changes without removing the axle, making it a favourite among club racers and serious hobbyists. Compatible with 5.5 mm pinions using the SIGMF55 hub (sold separately) or 6 mm pinions with the GMF60 hub (sold separately). Includes 1 crown and 3 shims of 0.1 mm for precise lateral adjustment. A reliable and versatile transmission component from Slot.it's established modular gear system.