MXL Z19 PULLEYS SET

MXL Z19 Pulley Pair: Belt Drive with Mechanical Precision

When tuning a slot car with belt drive, the quality of the pulleys makes the difference between a smooth and consistent turn or performance losses that are noticeable in every corner. This pair of MXL pulleys with 19 teeth (Z19), identified by reference CXM139, is designed for those who leave no mechanical detail to chance.

Main Features

• MXL Profile: standard miniature timing belt widely used in precision drives, with a pitch of 2.032 mm. Ensures exact and slip-free coupling with compatible MXL belts.
• 19 Teeth (Z19): number of teeth that defines the gear ratio and the pitch diameter of the pulley. Ideal for setups seeking a balance between top speed and acceleration response.
• Pair Format: the pack includes two identical pulleys, ready to be mounted on the motor shaft and the drive shaft simultaneously.

Function and Performance

MXL pulleys are the key component in belt drive systems. Unlike direct drive via crown gear and pinion, the timing belt smooths torque delivery, reduces vibrations, and allows some flexibility in the relative positioning between motor and rear axle. This results in a more progressive behaviour and a lower tendency for the car to destabilise under hard acceleration.

With 19 teeth in MXL profile, these pulleys offer a pitch diameter that fits well in balanced configurations for technical or medium-high speed circuits, although the final gear ratio will always depend on the number of teeth of the complementary pulley and the size of the mounted tyres.

Compatibility and Installation

The MXL profile is an open standard, so these pulleys are compatible with any MXL profile timing belt of the same pitch. For proper installation, it is essential to verify the inner diameter of the shaft where they will be installed, as the pulleys must fit precisely to avoid play that penalises the transmission.

It is recommended to check the alignment between both pulleys before tensioning the belt: a small lateral deviation can cause premature wear on both the belt and the pulleys themselves.

Ideal for…

• Tuners working with chassis that incorporate belt drive.
• Installations where the gear ratio needs to be optimised by adjusting the number of teeth on the pulleys.
• Club competitors looking to reduce vibrations and improve torque delivery smoothness.

Common Mistakes to Avoid

• Using a belt of a different profile (e.g., HTD) with MXL pulleys: the profiles are not interchangeable and the coupling would be incorrect.
• Installing the pulleys on a shaft that has not been cleaned of grease or dirt, which can cause slipping or unwanted axial movement.
• Not checking the tension of the belt after installation: neither too loose (slipping) nor too tight (bearing overload).

Frequently Asked Questions

What does the MXL profile mean in a timing pulley?

MXL (Miniature Extra Light) is a timing belt standard with a pitch of 2.032 mm, designed for small dimension drives and light loads. It is one of the most common profiles in precision slot installations due to its compactness and gear accuracy.

What does Z19 mean in the context of these pulleys?

Z19 indicates that the pulley has 19 teeth. This data is fundamental for calculating the gear ratio: the more teeth the driving pulley has compared to the driven one, the greater the reduction and available torque; conversely, it favours top speed.

Are these pulleys compatible with any MXL belt on the market?

Yes, as long as the belt is of MXL profile with the same pitch of 2.032 mm. The length of the belt should be chosen based on the axle distance of the specific installation.

Can I use just one pulley from this pair if I already have the other?

The pack includes two identical pulleys. If you already have one Z19 MXL pulley in good condition, you can use the second as a spare or for another installation, although it is common to replace both at the same time to ensure uniform wear in the transmission.

What axle diameter do these pulleys accommodate?

The information on the inner diameter of the shaft is not specified in the available product data. We recommend consulting with our team before placing the order if you have questions about compatibility with your specific shaft.

The CXM139 MXL Z19 pulley pair is a precision component for slot car belt-drive transmission systems. Featuring a standard MXL tooth profile with 19 teeth, these pulleys ensure accurate and slip-free power transfer from motor to rear axle. Compatible with all MXL timing belts, they are the go-to choice for slot car builders and club racers looking to fine-tune their drivetrain setup, reduce vibration, and improve throttle response on both technical and high-speed tracks.

Information Not Found

It has not been possible to confirm the inner diameter of the shaft (bore) of these pulleys or the exact manufacturing material from the available information. If you need this data for your installation, we recommend contacting us before placing the order.