Removable Pinion 13d. M50 ø6.5mm in Ergal for axle

Transmission Precision with the Scaleauto SC-1073E65 Removable Pinion

In the preparation of a slot car, the transmission is one of the points where lap time is gained or lost. Choosing the right pinion —in terms of tooth count, module, and material— makes the difference between a car that exits the chicane cleanly and one that slips or falls short on top speed. This removable pinion from Scaleauto meets that demand with clear specifications and top-quality materials.

Function and Technical Features

• Tooth Count: 13
• Module: 50 (M50)
• Axle Diameter: ø6.5 mm
• Material: Ergal (high-strength aluminium alloy, also known as aluminium 7075)
• Type: Removable
• Reference: SC-1073E65
• Brand: Scaleauto

Ergal is the material of choice in competition when aiming to reduce mass in rotating elements without sacrificing stiffness. Being a removable pinion, its installation and removal on the axle does not require special tools or adhesives, which speeds up gear ratio changes in the pits during a preparation session or between heats.

Compatibility and Installation

The axle diameter of ø6.5 mm determines which cars this pinion can be installed on. Before purchasing, check the diameter of your vehicle's rear axle. The module 50 must match the module of the crown gear it will mesh with: an M50 pinion only works correctly with crowns also of module 50. Combining different modules results in poor meshing, noise, and premature wear of both parts.

Scaleauto employs this standard in a large part of its transmission range, so this pinion fits naturally into setups that already use components from the same brand.

Why Choose Ergal Over Other Materials

Compared to stock plastic pinions, Ergal offers greater torsional stiffness and a more precise meshing surface, resulting in a more direct transmission. Compared to steel, it significantly reduces rotational mass, a relevant factor in lightweight cars where every gram in the drivetrain affects acceleration and motor response. It is the usual choice in competition categories where regulations allow it.

Gear Ratio: How Tooth Count Affects Performance

With 13 teeth, this pinion is aimed at relatively high gear ratios, favouring top speed on fast tracks or those with long straights. If the circuit is more technical, with many slow corners, a pinion with fewer teeth may be preferable to gain acceleration. Having several removable pinions in the toolkit is the most efficient way to adapt the car to each track without needing to change the crown gear.

Ideal For…

• Preparers and club drivers looking to optimise the transmission of their Scaleauto or compatible cars.
• Competitors who need to change the gear ratio quickly between sessions.
• Slot enthusiasts wanting to upgrade from stock components to performance parts made from higher-quality materials.

Frequently Asked Questions

What is the difference between a removable pinion and a fixed one?

A removable pinion is secured to the axle via a press fit or a lateral fixing screw, allowing it to be removed and replaced without damaging the axle. A fixed pinion is usually glued or permanently pressed on, making the change more laborious. For those who frequently adjust the gear ratio, the removable system is much more practical.

How do I know if module 50 is compatible with my crown gear?

The module must be identical in both pinion and crown for proper meshing. Check the reference of your crown: if it is M50 (or states "module 50" in its description), this pinion will fit. If your crown is M48 or another module, you will need a pinion of the same module as it.

Is the diameter ø6.5 mm for the axle or the pinion itself?

It is the inner diameter of the pinion, that is, the diameter of the axle it mounts onto. Measure the rear axle of your car before ordering: if it measures 6.5 mm, this pinion is the right one.

Does Ergal wear out faster than steel?

Ergal is softer than steel, so in very intensive use, it may show slightly more wear. However, in the context of competitive or club slot racing, its lightness and improved transmission more than compensate for that difference. Many preparers combine Ergal pinions with nylon or steel crowns to balance durability and performance.

Can I use this pinion on a Sidewinder motor car?

Yes, as long as the rear axle of the car has a ø6.5 mm diameter and the crown gear is of module 50. The motor configuration —Sidewinder, Inline, or Anglewinder— determines the motor's position, not the type of pinion required. What you need to verify is the axle diameter and the module of the crown, regardless of how the motor is oriented.

The Scaleauto SC-1073E65 is a 13-tooth removable pinion gear in Ergal (7075 aluminium alloy), module 50, designed for axles with a ø6.5 mm diameter. A key slot car upgrade part for competition and club racing, offering reduced rotational mass and precise gear mesh. Compatible with Scaleauto and other slot car brands using M50 transmission standards. Ideal for sport slot racing, gear ratio tuning, and performance preparation on Carrera Sport track or universal track layouts.