8t pinion M50 steel for 2mm shaft ø5.0mm x 2mm

Steel transmission with exact measurements: the pinion that leaves no room for error

The SC-1128B50 pinion from Scaleauto is a transmission component made of steel, featuring 8 teeth and module 50, specifically designed for 2 mm diameter axles. Its outer diameter is 5.0 mm and its width is 2 mm, making it a very specific option for setups that require millimetric precision in the gear ratio.

Function and performance

The pinion is the gear that is attached to the motor shaft and transmits movement to the crown gear. The correct choice of the number of teeth directly determines the car's gear reduction ratio, influencing acceleration, top speed, and overall track behaviour. An 8-tooth pinion combined with crowns with a higher number of teeth offers a shorter ratio, favouring acceleration over maximum speed: a common configuration on tracks with many curves and demanding lane exits.

Manufacturing in steel ensures a significantly higher durability compared to plastic or nylon pinions, with less deformation under load and greater resistance to progressive wear, especially relevant in intense practice sessions or club competitions.

Compatibility and installation

This pinion is designed for 2 mm axles, the most widely used standard diameter in competitive and prepared slot cars. Before installation, it is advisable to verify that the module of the crown gear it will be combined with is also module 50, an essential condition for correct and quiet meshing.

• Teeth: 8
• Module: 50
• Axle diameter: 2 mm
• Outer diameter: 5.0 mm
• Width: 2 mm
• Material: Steel
• Brand: Scaleauto
• Reference: SC-1128B50

Installation and preparation

For optimal installation, it is crucial to align the pinion correctly with the crown gear in the same plane, avoiding any lateral misalignment that could generate vibration or premature wear. It is recommended to secure the pinion to the axle with the appropriate fastening system (tightening screw or specific adhesive for gears, depending on the car design) and check the gear play with the crown before finalising the installation. A minimal play between teeth —neither too tight nor excessively loose— is key for smooth and efficient transmission.

Common mistakes

• Combining pinions and crowns of different modules: the resulting meshing is poor and causes skipping, noise, and accelerated wear.
• Mounting the pinion on an axle of a diameter other than 2 mm without an adapter: compromises the fastening and centring.
• Not checking the lateral alignment between pinion and crown before closing the chassis.

Frequently asked questions

What does module 50 mean in a pinion?

The module is a measurement that defines the size of the gear teeth. For the pinion and crown to mesh correctly, both must share the same module. In slot racing, module 50 (equivalent to 0.5 mm) is one of the most common standards in competition and prepared components.

Is this pinion compatible with crowns from other brands?

Yes, as long as the crown has the same module (M50) and the axle diameter is compatible. The module is the determining parameter for compatibility between gears, regardless of the manufacturer brand.

When is it advisable to use an 8-tooth pinion instead of one with more teeth?

A pinion with fewer teeth offers a shorter gear ratio: more acceleration and lower top speed. It is a common choice on technical tracks with many curves. If the track has long straights, a pinion with more teeth may be beneficial to achieve higher maximum speed.

Do I need any special tools to install this pinion?

For precise installation without damaging the pinion or axle, it is recommended to use a specific pinion puller/installer for slot racing. Forcing the installation under pressure without the proper tool can misalign the pinion or mark the axle.

Is a steel pinion always better than a plastic one?

In general, steel offers greater durability and wear resistance. However, in some recreational use configurations or with low-power motors, a nylon pinion may be sufficient and provides more quiet operation. For competition or intense practice, steel is the usual choice.

The Scaleauto SC-1128B50 is an 8-tooth steel pinion gear, module 50, designed for 2 mm axles, with a 5.0 mm outer diameter and 2 mm width. An essential slot car transmission part for club racing preparation and competitive slot car setups requiring precise gear ratios and reliable steel construction.