Removable pinion 14d. M50 ø7.5mm in Ergal for 2mm shaft with fixation by M2.5mm screw.

Precision Machined Ergal: the Scaleauto Removable Pinion for 2 mm Axles that Makes a Difference in Preparation

The pinion is one of the most critical components of any slot transmission. Its module, number of teeth, and especially the material it is made from directly determine the efficiency of the transmission, wear over sessions, and the car's behaviour on track. The SC-1074E75 from Scaleauto meets all these demands with a design aimed at discerning preparers.

Technical Features

• Number of teeth: 14 t.
• Module: M50
• Outer diameter: 7.5 mm
• Material: Ergal (high-strength aluminium alloy)
• Axle diameter: 2 mm
• Fixing system: M2.5 mm screw
• Reference: SC-1074E75
• Brand: Scaleauto

Function and Performance

Ergal —7075 aluminium alloy— is the reference material in competition preparations for a simple reason: it offers a significantly higher strength-to-weight ratio than conventional aluminium and plastic, without adding unnecessary mass to the transmission. A lighter pinion reduces rotational inertia, resulting in a quicker response to acceleration and less load on the motor.

The fixing system using a M2.5 mm screw ensures that the pinion remains securely attached to the axle without slipping, even under the demands of a technical track with repeated braking and acceleration. Unlike press-fit pinions, the screw allows for the removal and reassembly of the pinion without damaging the axle or the pinion itself, extending the lifespan of the assembly.

Compatibility and Installation

This pinion is designed for 2 mm diameter axles, the most common standard in 1/32 and 1/24 scale slot racing cars. Being module 50, it must be combined with crowns of the same module to ensure correct meshing and no play.

The removable feature makes it particularly interesting when working with different gear ratios depending on the layout: simply loosen the screw, change the pinion, and readjust, without the need to disassemble the entire chassis or heat the axle.

Installation and Preparation

• Ensure the axle is clean and free of burrs before mounting the pinion to guarantee a perfect fit.
• Tighten the M2.5 screw with an appropriate screwdriver or Allen key, firmly but without over-torquing to avoid damaging the thread of the Ergal.
• Check the backlash (play between pinion and crown) once mounted: a minimal but present play is ideal for smooth and durable transmission.
• If you frequently change the gear ratio, keep several pinion sizes on hand to avoid wearing out the fixing hole due to excessive mounting and dismounting.

Common Mistakes

• Mixing modules: using this M50 pinion with crowns of a different module causes poor meshing, noise, and premature wear of both parts.
• Over-tightening the screw: Ergal is strong, but a forced thread can render the pinion unusable. Use the correct tool and apply progressive torque.
• Not checking axle-crown alignment: a perfectly mounted pinion can lose performance if the assembly is not laterally aligned with the crown.

Frequently Asked Questions

What advantage does Ergal have over plastic or standard aluminium in a pinion?

Ergal (7075 alloy) is harder and more resistant than common aluminium, with a very low weight. In a pinion, this means greater durability against wear and lower rotational inertia, improving motor response and transmission efficiency.

Is this pinion compatible with crowns from other brands?

Yes, as long as the crown is also module 50. The module is the parameter that defines gear compatibility, regardless of the manufacturer brand.

What scales is it suitable for?

The 2 mm axle diameter is the usual standard in 1/32 and 1/24 slot racing cars. Always check the diameter of your axle before ordering.

Can I mount and dismount this pinion multiple times without damaging it?

Yes. That is precisely the advantage of the removable system with a screw compared to press-fit pinions. With careful maintenance and without forcing the screw, the pinion can be disassembled and reassembled multiple times.

What tool do I need for the M2.5 fixing screw?

An Allen key (internal hex) of the appropriate size for the M2.5 screw. Scaleauto and other brands in the sector sell precision Allen key sets specifically for slot preparation.

What gear ratio do I get with this 14-tooth pinion?

The gear ratio depends on the number of teeth of the crown you combine it with. Divide the teeth of the crown by those of the pinion (14) to obtain the ratio. A higher ratio means more top speed but less acceleration; a lower ratio means better start but less maximum speed.

The Scaleauto SC-1074E75 is a 14-tooth M50 module removable pinion gear, 7.5 mm outer diameter, machined in Ergal (7075 aluminium alloy) for 2 mm axles, secured with an M2.5 screw. Designed for 1/32 and 1/24 slot car racing, it delivers reduced rotational inertia, precise engagement and easy gear ratio changes — an essential component for competitive slot car preparation and tuning.