12d pinion. Ergal. ø7.5mm for 2mm axle

12-tooth Ergal Pinion from Scaleauto: lightweight and precise transmission for 2 mm axle

When working on a slot car's transmission, the choice of pinion makes the difference between a well-adjusted chassis and one that vibrates or wastes power. This pinion from Scaleauto, reference SC-1095E75, offers 12 teeth, an outer diameter of 7.5 mm, and is mounted on a 2 mm axle, all made from Ergal aluminium alloy.

Main features

• Number of teeth: 12
• Outer diameter: ø 7.5 mm
• Axle diameter: 2 mm
• Material: Ergal (high-strength aluminium alloy)
• Manufacturer: Scaleauto
• Reference: SC-1095E75

Function and performance

Ergal is an aluminium alloy particularly valued in slot preparation for its strength-to-weight ratio. Compared to plastic or nylon pinions, it offers greater rigidity and durability without adding unnecessary mass to the transmission system. This translates into a more direct throttle response and less energy loss due to flexing or deformation of the pinion under load.

With 12 teeth and 7.5 mm diameter, this is a relatively small pinion that, when combined with a crown gear of a higher tooth count, provides a longer gear ratio: ideal for circuits with long straights where top speed is sought.

Compatibility and installation

Designed for 2 mm diameter axles, a common measurement in various slot setups both in inline and sidewinder configurations. Before installation, it is advisable to check that the tooth pitch of the pinion matches that of the crown gear it will work with. Scaleauto offers compatible crown gears in its spare parts catalogue.

For correct installation, ensure the pinion is aligned with the crown gear without forcing the axle, apply the fixing screw with the appropriate torque, and check that there is no lateral play. A slight misalignment can generate noise, premature wear, and loss of efficiency.

Ideal for…

This pinion fits well in club or championship competition-oriented setups, where every gram and every tenth of a second counts. It is also a solid option for those experimenting with different gear ratios in search of the optimal balance between acceleration and top speed depending on the track layout.

Common mistakes

• Mixing pinions and crown gears with different tooth pitches: this generates noise and accelerated wear.
• Over-tightening the fixing screw on the axle, which can create marks and hinder future adjustments.
• Not checking the lateral alignment between pinion and crown gear before running.

Frequently asked questions

Which Scaleauto crown gears is this pinion compatible with?

It must be combined with crown gears of the same tooth pitch. Check the Scaleauto crown gear catalogue and verify the module before placing an order to ensure correct meshing.

What advantage does Ergal have over nylon in a slot pinion?

Ergal is stiffer and more resistant to deformation under load, which improves transmission efficiency. Nylon, on the other hand, can absorb slightly more impact but exhibits greater flexing and wear over the long term in intensive use.

Is it suitable for inline and sidewinder configurations?

Yes. The pinion itself is not conditioned by the type of motorisation; what matters is that the axle is 2 mm and that the crown gear is compatible in pitch and position within the chassis.

What gear ratio does a 12-tooth pinion offer?

The ratio depends on the number of teeth of the crown gear it is combined with. The greater the difference between crown and pinion, the greater the reduction and more traction force; a tighter ratio favours top speed. With 12 teeth on the pinion, combined with crown gears of 27-32 teeth, common ratios in competition are achieved.

Do I need special tools to install it?

A standard Allen key of the appropriate size for the pinion's fixing screw is sufficient. It is recommended to use a tooth pitch gauge or simply run the car carefully for the first few meters to detect any potential friction before tightening definitively.

The Scaleauto SC-1095E75 is a 12-tooth Ergal aluminium pinion gear with a 7.5 mm outer diameter, designed for 2 mm axles. A lightweight, precise slot car transmission component ideal for club racing and custom gear ratio setups. Compatible with Scaleauto crown gears sharing the same tooth pitch.