14 Brass Pinion ø7.5mm for 2mm Shaft.

Transmission Precision: 14-Tooth Brass Pinion for 2 mm Axle

The pinion is one of the most influential components in the behaviour of a slot car. Its number of teeth, material, and fit to the axle directly determine the gear ratio, corner exit response, and top speed on the straight. This Scaleauto pinion, with 14 teeth, an outer diameter of 7.5 mm, and a fit for 2 mm axle, provides a solid foundation for configuring the gearing of your setup.

Main Features

• Number of teeth: 14
• Outer diameter: 7.5 mm
• Axle diameter: 2 mm
• Material: Brass
• Reference: SC-1097A75
• Manufacturer: Scaleauto

Brass as a Transmission Material

Brass is a classic and proven choice for slot pinions for several reasons. It offers good wear resistance when meshing with plastic, nylon, or delrin crowns, reduces vibration transmission, and is easy to machine accurately. Compared to steel pinions, brass is gentler on the crown, especially in street setups or club circuits where backlash adjustments are not always perfect.

Function and Performance

A 14-tooth pinion falls within the mid-low range of the typical spectrum in slot (which usually ranges from 9 to 16 teeth depending on the application). Combined with the appropriate crown, it allows for fine-tuning the gear ratio to prioritise torque in circuits with many curves or to seek a balance between acceleration and top speed on mixed layouts.

The diameter of 7.5 mm is a key detail: it influences the centre distance with the crown and, therefore, the final backlash of the drivetrain. Before mounting, it is advisable to check that this diameter is compatible with the distance between the motor axle and the rear axle of your chassis.

Compatibility and Mounting

This pinion is sized for 2 mm diameter axles, a standard measurement in most slot motors used in 1/32 and 1/24 scale cars. It is suitable for Sidewinder (motor parallel to the rear axle), Inline (motor in line with the rear axle), and Anglewinder (angled motor) setups, provided the pinion module is compatible with that of the crown used.

Scaleauto works with a 0.5 module in its range of pinions and crowns, which is the most widespread module in slot. Ensure that your crown is also a 0.5 module before combining them.

Common Mistakes When Working with Pinions

• Not verifying the module: a pinion and a crown must share the same module to mesh correctly. Different modules cause premature wear and noise.
• Excessive fit on the axle: pressing the pinion too hard can deform it or create stresses that affect meshing. Use the appropriate tool for mounting.
• No backlash: the transmission needs a minimum of play to function without straining the motor. A too-tight meshing generates heat and loss of performance.
• Not checking concentricity: after mounting, turn the axle by hand and check that the pinion does not wobble. A small eccentricity is very noticeable in rolling.

Frequently Asked Questions

Which crowns is this pinion compatible with?

With any 0.5 module crown designed for the same centre distance. Scaleauto offers several crowns in its catalogue that fit this pinion; it can also be combined with crowns from other brands as long as the module is 0.5 and the chassis geometry allows it.

Is this pinion suitable for motors with a 2 mm axle from any brand?

Yes, the 2 mm axle diameter is a standard measurement shared by most common slot motors in 1/32 scale. Also check the module and outer diameter to ensure that the centre distance of your chassis is appropriate.

What is the difference between using 14 teeth and, for example, 11 teeth?

With more teeth on the pinion (and the same crown), the gear ratio shortens: the car accelerates less sharply but reaches a higher top speed. With fewer teeth, the opposite occurs: more torque, more aggressiveness on corner exits. Choosing the correct number of teeth depends on the layout and the motor used.

Do I need any special tools to mount it?

It is recommended to use a pinion puller/installer to avoid damaging either the pinion or the axle. Hitting directly with a hard object can misalign the pinion or mark the axle.

Is brass better than nylon for this type of pinion?

It depends on the use. Brass is more dimensionally precise and withstands heat well; nylon absorbs more impacts and is quieter. For competition setups where precision and durability are sought, brass is a well-established option.

The Scaleauto SC-1097A75 is a 14-tooth brass pinion gear with a 7.5 mm outer diameter, designed for 2 mm motor axles. Compatible with 0.5 module gears, it suits Sidewinder, Inline, and Anglewinder slot car setups in 1/32 and 1/24 scale. A reliable choice for fine-tuning gear ratios on club or competition tracks.