MXL Z20 PULLEYS SET

MXL Z20 Pulley Pair: Precision Belt Drive for Competitive Racing

The MXL Z20 pulleys (reference CXM140) are designed for belt drive systems in slot cars. The MXL profile is one of the most widely used standards in this type of mechanics: fine pitch teeth, low backlash, and a smooth, continuous torque transmission that reduces power losses between the motor and the axle.

The number of teeth Z20 defines the transmission ratio when combined with a pulley of different tooth count on the motor shaft or the rear axle. The greater the difference between the two pulleys, the greater or lesser the speed reduction, allowing for fine-tuning of the car's behaviour according to the track and race conditions.

Main Features

• MXL Profile: 0.080" (2.032 mm) pitch, a common standard in competitive slot car belt drives.
• 20 Teeth (Z20): tooth count that allows for configuring varied transmission ratios by combining pulleys with different numbers of teeth.
• Supplied in Pairs: the pack includes two pulleys, ready to be mounted on the motor and rear axle.
• Smooth Transmission: the MXL profile minimises backlash and vibrations compared to direct gear transmissions.

Recommended Applications

This type of pulley is used in belt drive configurations where partial isolation of motor vibrations is sought, achieving a more progressive power delivery. They are particularly common in competition-ready chassis for club racing or in cars with Sidewinder or Anglewinder configurations where the motor-axle geometry allows it.

Assembly and Preparation

For correct assembly, it is essential to pair these pulleys with an MXL belt of the appropriate pitch and length for the chassis. The tension of the belt directly influences performance: too much tension generates friction and power loss; too much slack causes jumps and loss of synchronisation. It is recommended to check the alignment between both pulleys before securing the motor in its final position.

Compatibility

The MXL Z20 pulleys are compatible with any belt drive system that uses the standard MXL profile. Compatibility with a specific chassis depends on the inner diameter of each pulley’s axle and the design of the mounting; it is advisable to verify these dimensions before assembly.

Frequently Asked Questions

What is the difference between a belt drive with MXL pulleys and a crown and pinion drive?

The belt drive better absorbs micro-vibrations from the motor and allows greater flexibility in positioning the motor-axle assembly. The crown and pinion drive is more direct and offers greater rigidity but can transmit more vibrations to the chassis. Each system has its application depending on the preparation style and type of circuit.

What belt should I use with these pulleys?

With an MXL profile belt. The specific length depends on the centre-to-centre distance of the two pulleys on the chassis. It is advisable to measure it before purchasing the belt or consult the documentation for the chassis in question.

Does the pack include only the pulleys or also the belt?

The CXM140 pack includes the pair of MXL Z20 pulleys. The drive belt is purchased separately, as its length varies depending on the chassis.

Can I combine a Z20 pulley with another of different tooth count to adjust the transmission ratio?

Yes. This is precisely one of the advantages of pulley systems: by combining different tooth counts on the motor and rear axle, the speed reduction can be fine-tuned to adapt to different tracks or motors.

What type of motorisation is this system most commonly used for?

Belt drives with MXL pulleys are used in both Sidewinder and Anglewinder configurations, depending on the chassis design and the motor mounting used.

The CXM140 MXL Z20 pulley pair is a precision component for slot car belt drive systems. Using the MXL profile standard, these 20-tooth pulleys allow fine-tuning of the transmission ratio when combined with pulleys of different tooth counts. Ideal for club racing and custom chassis builds, they offer smooth power delivery and reduced backlash compared to direct gear transmission. Compatible with any MXL belt drive setup — a trusted choice for slot car builders and competitive racers looking for consistent, reliable performance on the track.