Crown gear 31d. Anglewinder 25° Procomp-R

The Anglewinder crown gear that makes a difference in competition setups

The 31d. Anglewinder 25° ProComp-RS M50 Reverse crown gear from Scaleauto (ref. SC-1171BR) is a transmission component specifically designed for anglewinder configurations, where the motor is positioned at an angle relative to the rear axle. This geometry allows for better use of the internal space of the chassis and optimises mass distribution, something that club preparers are well aware of.

Technical specifications

• Number of teeth: 31
• Angle: 25°
• Diameter: Ø17 mm
• Compatible axle: 2.38 mm
• Fixing: M2.5 screw
• Version: Reverse
• Series: ProComp-RS M50
• Reference: SC-1171BR

Function and performance

The Reverse version indicates that the crown gear is designed for motors that rotate in the opposite direction to the standard. This is common in certain anglewinder chassis configurations where the motor is oriented in the reverse direction to optimise weight distribution or comply with specific championship regulations. Before purchasing, it is advisable to confirm the rotation direction of the motor installed in your chassis.

With 31 teeth and a diameter of 17 mm, this crown gear offers a gear ratio that balances acceleration and top speed depending on the pinion it is paired with. The machining quality of Scaleauto's ProComp-RS M50 series is recognised in the preparation community for its concentricity and the cleanliness of the tooth profile, factors that reduce vibrations and extend the lifespan of the pinion-crown assembly.

Compatibility and installation

Designed for 2.38 mm axles, the most common diameter in 1/32 scale competition slot cars. The fixing with an M2.5 screw allows for a secure adjustment without the risk of slipping under load, especially important on Sport track systems (Scaleauto, Slot.it) where traction is demanding.

The 25° angle is the most commonly used standard in anglewinder setups within the ProComp-RS category, making it compatible with the vast majority of Scaleauto chassis designed for this configuration. Always consult your chassis documentation to verify the required angle before replacing the crown gear.

Installation and preparation

For optimal performance, we recommend cleaning the axle and ensuring it is free of burrs before installing the crown gear. The tightening of the M2.5 screw should be firm but without forcing the material: excessive torque can deform the housing. Lightly lubricate the gear with a specific slot oil and check the backlash until you find the point of least friction without excessive metal contact.

Ideal for…

• Preparers and club drivers competing with Scaleauto anglewinder chassis.
• Those looking to replace a worn crown gear while maintaining the original gear ratio.
• Experimenting with different pinion-crown ratios to adjust the car's behaviour to different tracks.

Points to consider

• The Reverse (BR) version is not interchangeable with the standard version (B): verify the rotation direction of your motor.
• The 25° angle must match the angle of your motor mount or support.
• This crown gear belongs to the M50 series: ensure it is paired with a pinion of the same module to guarantee correct meshing.

Frequently asked questions

What is the difference between the standard version and the Reverse (BR) version?

The Reverse version is manufactured for motors that rotate in the opposite direction to the usual. If you mount a Reverse crown gear with a standard motor, the car will go backwards. Always check the rotation direction of your motor before choosing the version.

Which pinions is this crown gear compatible with?

As it belongs to Scaleauto's M50 series, it should be paired with pinions of module 50 (M50). Using pinions of a different module will result in incorrect meshing, noise, and premature wear.

Is it valid for 3/32" (2.38 mm) axles?

Yes. The diameter of 3/32" is exactly equivalent to 2.38 mm, which is the axle for which this crown gear is designed.

Can I use this crown gear on Scalextric or Ninco track systems?

The crown gear itself does not depend on the type of track, but on the chassis and motor of the car. What matters is that your chassis configuration is anglewinder at 25°, the axle is 2.38 mm, and the motor rotates in the Reverse direction.

When should I change the crown gear?

When you notice meshing noise that does not disappear by adjusting the backlash, visible wear on the teeth, or loss of smoothness in the transmission. In club competition, regular inspection of the pinion-crown assembly extends the life of both components.

The Scaleauto SC-1171BR is a 31-tooth anglewinder crown gear at 25°, ProComp-RS M50 series, Reverse version, designed for 2.38 mm axles and M2.5 screw fixing, with a 17 mm diameter. A precision slot car transmission part for competitive anglewinder setups in 1/32 scale racing.