Sidewinder crown gear 38t

Reliable transmission for your sidewinder setup with the NSR 38-tooth crown gear

The NSR6138 crown gear is a specific transmission component for sidewinder configurations —that is, with the motor positioned parallel to the rear axle— manufactured with the precision that characterises NSR. With 38 teeth, a 2.38 mm axle, and an overall diameter of 18.5 mm, it fits seamlessly into the most common sets on the market.

Technical specifications

• Number of teeth: 38T
• Diameter: 18.5 mm
• Compatible axle: 2.38 mm
• Mounting type: Sidewinder (motor parallel to the rear axle)

Compatibility

This crown gear is suitable for chassis and transmission sets from Scalextric, Fly, and Sloter. If you are preparing or tuning one of these cars and need to replace the original crown gear or change the gear ratio, the NSR6138 is a direct option with no adaptations required.

Function and performance

The choice of 38 teeth places this crown gear within the usual range for club tracks and recreational use, offering a balance between acceleration and top speed. NSR manufacturing ensures a uniform tooth profile that reduces play in the transmission and minimises vibrations, resulting in smoother and more predictable running.

As an NSR replacement part, dimensional tolerance is controlled: the fit on the 2.38 mm axle is snug without the need to force the installation, which is especially appreciated when working on a delicate chassis.

Installation and preparation

Installation is straightforward: align the crown gear with the motor pinion before securing it permanently to ensure that the teeth mesh correctly. A small dab of glue or the usual securing screw (depending on the chassis) is sufficient to keep it in place during competition. Always check the play between the crown gear and pinion: neither too tight nor with excessive play.

Common mistakes

• Installing the crown gear without checking alignment with the pinion, leading to premature wear and noise.
• Using a crown gear with a different axle size (for example, 3/32") on a 2.38 mm set: the fit will not be correct even if it visually appears to fit.
• Applying too much adhesive, which can contaminate the teeth and cause irregularities in the transmission.

Frequently asked questions

Is this crown gear suitable for inline or anglewinder setups?

No. The NSR6138 is specifically designed for sidewinder configurations, where the motor is parallel to the rear axle. For inline or anglewinder setups, there are specific references with adapted geometry.

Which pinions is it compatible with?

The available information does not specify the tooth module or compatible pinions. We recommend consulting the NSR transmission table or contacting us before combining it with pinions from other brands.

Can it be used on Ninco or Carrera tracks?

The manufacturer's indications specify compatibility with Scalextric, Fly, and Sloter. For Ninco or Carrera chassis, it is advisable to check the axle measurements and available space in the transmission set before installation.

When should the crown gear be replaced?

When you observe visible wear on the teeth, excessive play in the transmission, or unusual noise during operation. A worn crown gear directly affects the consistency of the running and can damage the pinion.

The NSR6138 is a 38-tooth sidewinder crown gear for slot car transmission setups, featuring a 2.38 mm axle diameter and 18.5 mm overall diameter. Compatible with Scalextric, Fly, and Sloter chassis, it delivers smooth and precise power transfer. A reliable NSR replacement part for club racing and hobby enthusiasts looking for consistent performance on any track layout.