9-tooth brass pinion ø5.5mm for 2mm axle.

Precision in Every Gear: the Scaleauto SC-1092A55 Pinion for 2 mm Axles

In slot racing, the transmission is one of the most critical points of the setup. A well-chosen pinion makes the difference between a smooth and progressive response or power losses that are noticeable as soon as you leave the pit. This 9-tooth brass pinion, with a 5.5 mm outer diameter and designed for a 2 mm axle, meets the demands of the most meticulous tuners.

Main Features

• Number of teeth: 9
• Material: Brass
• Outer diameter: 5.5 mm
• Axle diameter: 2 mm
• Reference: SC-1092A55
• Brand: Scaleauto

Function and Performance

The pinion is the gear that transmits the motor's rotation to the crown gear, determining, along with it, the final gear ratio of the car. With 9 teeth, this pinion is aimed at configurations that seek a balance between acceleration and top speed, always depending on the crown gear it is paired with.

Brass is a common material in performance pinions for several reasons: it offers good wear resistance, operates smoothly against plastic or other metal crowns, and absorbs vibrations better than steel in certain combinations. The result is a quieter transmission and more controlled wear over sessions.

Compatibility and Installation

This pinion is designed for 2 mm diameter axles, a widely used measurement in competition slot cars and setups with open can motors. Before installing it, it is advisable to check that the pinion's module is compatible with that of the crown gear you already have mounted, as a difference in module will create an incorrect mesh even if the axle measurements are the same.

The fit on the axle should be firm. If there is play, it can be corrected with a bit of axle retaining adhesive; if there is excessive tension, a light touch-up with precision tools will solve the problem without damaging the part.

Ideal for…

This spare part fits particularly well in:

• Preparations and setups of slot cars on Sport track (Scaleauto, Slot.it).
• Replacement of worn pinions in club racing cars.
• Fine-tuning of the gear ratio to adapt the car to different layouts.
• Custom builds with motors in sidewinder, inline, or anglewinder configurations using a 2 mm axle.

Considerations

Changing the pinion is one of the quickest ways to adjust the car's behaviour without touching the motor. A pinion with fewer teeth multiplies acceleration but reduces top speed; one with more teeth does the opposite. With 9 teeth, this piece is positioned in the low-medium range, useful for layouts with many curves or when a livelier pit exit is desired.

Check the condition of the pinion periodically: wear on the flanks of the teeth is the clearest sign that it is time to replace it. Keeping the transmission in good condition also extends the lifespan of the motor and crown gear.

Frequently Asked Questions

Which crown gears is this pinion compatible with?

Compatibility depends on the gear module, not just the physical measurements. Ensure that the module of this pinion matches that of the crown gear you are using. Scaleauto offers crowns in different modules; consult the specifications of both parts before combining them.

Why choose brass over other materials?

Brass works well with technical plastic and other metal crowns, reduces transmission noise, and has progressive and predictable wear. It is a classic choice in slot preparation precisely for its balance between hardness and smooth meshing.

How do I properly secure the pinion to the axle?

The usual practice is to use anaerobic axle retaining adhesive (like Loctite 603 or similar) in the right amount. Apply a small drop, position the pinion correctly relative to the crown gear, and allow it to cure before running. Excess adhesive can hinder future replacements.

When should I replace the pinion?

When you notice play in the transmission, unusual noise in the mesh, or loss of traction without apparent cause in the motor. Visually, worn teeth present rounded or asymmetrical flanks. It is a consumable part: having spare units in the pit box is good practice.

Is it valid for any motor configuration?

Yes, as long as the motor uses a 2 mm axle. It works in both sidewinder and inline and anglewinder configurations, as the function of the pinion is the same regardless of the motor's orientation relative to the rear axle.

The Scaleauto SC-1092A55 is a 9-tooth brass pinion gear with a 5.5 mm outer diameter, designed for 2 mm axles. A reliable and precise spare part for slot car transmission setups, widely used in club racing and custom builds on Sport track systems. Compatible with Scaleauto and Slot.it configurations, this pinion is a go-to choice for hobbyists fine-tuning gear ratios for different circuit layouts.