Shaft 2.38 (3/32) Steel 55mm

The BRM-S107B Steel Axle: Precision and Reliability in Every Millimetre

When it comes to spare parts for 1/24 slot cars, the details make the difference between a well-tuned car and one that does not inspire confidence on track. The BRM-S107B axle is the official replacement part from BRM for those setups that require an axle with a 2.38 mm diameter (equivalent to 3/32") and 55 mm length, made of steel to ensure rigidity, concentricity, and durability.

Function and Performance

The axle is one of the most critical components of a slot car's rear end. Its function is to transmit the motor's rotation to the rear wheels with minimal energy loss. To achieve this, it must meet very tight tolerances:

• Concentricity: an axle that is not perfectly straight generates vibrations, loss of traction, and premature wear on bearings and crown gears.
• Material Hardness: the steel used in this axle withstands torsional stress without deforming with continuous use.
• Standard 3/32" Size: the 2.38 mm diameter is one of the most widely used standards in 1/24 scale, facilitating compatibility with crown gears, pinions, and bearings of the same pitch.

Compatibility

This axle is specifically designed for BRM models that use the 3/32" measurement in their rear end. Always check that the bearings and crown gear of your car accept this diameter before installation. If in doubt, consult the manual or technical sheet of the corresponding BRM model.

Installation and Preparation

A good axle installation is as important as the quality of the part itself. Some practical tips:

1. Check the straightness of the axle by rolling it on a flat surface before installing it.
2. Ensure that the bearings are well seated in the chassis before inserting the axle.
3. Mount the crown gear centred and tighten the fixing screw with the right pressure: not too loose or too tight to avoid generating stress.
4. After installation, check that the axle rotates freely without rubbing before closing the chassis.

Common Mistakes

• Reusing a Bent Axle: even if it appears straight at first glance, a deformed axle significantly penalises performance. If in doubt, replace it.
• Mixing Diameters: do not attempt to fit a 3/32" crown gear onto a 2 mm axle or vice versa. The fit must be exact to avoid play and loss of torque.
• Forcing Extraction: always use an appropriate axle puller to avoid damaging the bearings or the chassis.

Frequently Asked Questions

What does the 3/32" measurement mean and how many millimetres does it equal?

3/32 of an inch equals 2.38 mm. It is one of the most common axle diameters in 1/24 scale slot cars, determining which crown gears, pinions, and bearings are compatible with your setup.

Which BRM models is this axle compatible with?

This axle is designed as a replacement for BRM models that use the 3/32" measurement in the rear end. We recommend consulting the technical sheet of your specific BRM model to confirm compatibility before installation.

Can I use this axle with crown gears and bearings from other brands?

As long as they respect the standard 3/32" diameter (2.38 mm), yes. The measurement is standardised in the 1/24 slot sector, so compatibility is usually broad. In any case, check the fit tolerances of each component.

How do I know if my axle is bent and needs replacement?

Roll the axle on a flat and well-lit surface. If it describes an irregular path or you perceive wobbling when held by the ends, it is time to replace it. A damaged axle penalises the car's behaviour even at moderate speeds.

What length should I look for if I want a shorter or longer axle?

This model measures 55 mm. BRM and other brands in the sector offer axles in different lengths within the same diameter. Check the spare parts catalogue in the Axles and Bearings category to find the size you need.

The BRM-S107B is a 2.38 mm (3/32") diameter steel axle, 55 mm long, designed as an OEM replacement part for BRM 1/24 scale slot cars. Engineered for precision concentricity and durability, it ensures smooth power transmission from motor to rear wheels. Compatible with standard 3/32" crowns, pinions and bearings widely used in 1/24 slot racing. Available at Ministry of Hobby, your specialist in slot car parts, repuestos slot 1/24, BRM spare parts and slot car axles.