Removable Pinion 11d. M50 ø6.5mm ergal

Adjust the transmission to the millimetre with the removable pinion SC-1071E65 in ergal

The SC-1071E65 is a removable pinion gear with 11 teeth, module 50 and an outer diameter of 6.5 mm, machined from ergal —a high-strength, low-density aluminium alloy— for a 2 mm axle. The fixation is done using an M2.5 mm screw, which facilitates assembly and disassembly without special tools and allows for quick changes to the gear ratio between sessions.

Features and highlights

• Number of teeth: 11
• Module: 50
• Outer diameter: 6.5 mm
• Material: Ergal (high-strength aluminium alloy)
• Axle diameter: 2 mm
• Fixation: M2.5 mm screw
• Reference: SC-1071E65

Function and performance

The pinion is the starting point of the transmission in any slot car: together with the crown gear, it determines the gear reduction ratio and, therefore, the top speed and acceleration response. An 11-tooth pinion with module 50 allows for the construction of demanding gear ratios, aimed at fast tracks or high-torque motors where the goal is to multiply the output speed of the motor shaft.

Ergal offers two clear advantages over steel in competition applications: it reduces rotational weight —directly affecting motor response— and maintains sufficient rigidity for intensive use in clubs or test benches. It is not the material of choice if maximum long-term durability against steel is sought, but it is ideal when performance and weight savings are priorities.

Compatibility and installation

Suitable for any configuration using a rear axle with a 2 mm diameter and a crown gear with module 50. The screw fixation system M2.5 mm ensures the pinion's position without axial play and allows it to be removed with an appropriate screwdriver in seconds, which is very practical in tuning sessions where various gear ratios are tested.

Before installation, it is advisable to check that the face of the pinion is perfectly aligned with the crown gear to avoid premature wear and noise in the transmission. A small axial adjustment in positioning can make a difference in smooth running.

Common mistakes

• Over-tightening the fixation screw: it can deform the ergal housing. Tighten firmly but without forcing.
• Combining different modules: ensure that the crown gear it pairs with is also module 50.
• Not checking the pinion-crown alignment before running: causes uneven wear and loss of efficiency in the transmission.

Frequently asked questions

What is the difference between ergal and steel in a slot pinion?

Ergal is a much lighter aluminium alloy than steel. This reduces the rotational mass on the motor shaft, improving acceleration response. In return, its wear resistance over the very long term is lower than that of steel, although for club or regular competition use, it is more than sufficient.

Which crown gears is this pinion compatible with?

With any crown gear of module 50. This is the parameter that determines gear compatibility, regardless of the number of teeth or the material of the crown gear.

Can I use this pinion on an axle with a diameter other than 2 mm?

No. The inner housing is designed for a 2 mm axle. Using an axle of a different diameter would cause play or make installation impossible.

What screw do I need to secure it?

The fixation screw is of type M2.5 mm. It is usually tightened with an appropriately sized Allen screwdriver. Ensure you have the correct tool before mounting the pinion.

How many teeth is it advisable to use according to the type of track?

In general, fewer teeth on the pinion implies higher top speed and less acceleration; more teeth provide greater traction during acceleration but lower maximum speed. The 11 teeth of this pinion are aimed at high-speed configurations. The optimal adjustment always depends on the motor, the chosen crown gear, and the specific layout.

The SC-1071E65 is an 11-tooth, module 50, 6.5 mm outer diameter ergal pinion gear for 2 mm axles, secured by an M2.5 mm grub screw. Designed for slot car competition and club racing, it reduces rotational mass for faster motor response. Compatible with all module 50 crown gears. A precise, lightweight upgrade for drive train tuning in 1/32 and compatible slot racing formats.