9-tooth inline pinion 5.5mm (X2)

Slot.it Pinions for Inline Motor: Small in Size, Big in Precision

The pinion is one of the components that most influences the final behaviour of a slot car, and Slot.it knows this well. This reference SIPI09 offers two pinions with 9 teeth and 5.5 mm diameter, designed for inline motor setups, meaning the motor is arranged longitudinally with respect to the rear axle.

Main Features

• Number of teeth: 9
• Diameter: 5.5 mm
• Configuration: inline motor
• Units per pack: 2
• Reference: SIPI09
• Manufacturer: Slot.it

Function and Performance

With 9 teeth, this pinion provides a relatively high gear ratio when combined with larger crown gears, resulting in more torque available at low speed. It is a common choice on tracks with many curves, where speed recovery after each braking is crucial.

Slot.it's manufacturing ensures tight tolerances and a clean fit with crown gears of the same brand, minimising play and reducing energy loss in the transmission.

Compatibility and Installation

These pinions are designed for Slot.it's inline transmission system. Before installing them, check that the motor shaft diameter matches the pinion hole and that the alignment with the crown gear is correct. Poor alignment can lead to premature wear on both the pinion and the crown gear.

To achieve the best performance, combine them with Slot.it crown gears of the same module and ensure that the play between both parts is as minimal as possible without causing contact.

Common Mistakes

• Forcing the pinion onto the shaft without first checking the diameter: this can damage the part or cause an excessively loose fit.
• Mixing pinions and crown gears of different modules: this compromises the mesh and generates noise and wear.
• Not checking the pinion-crown alignment after installation: this is the most common cause of performance loss in the transmission.

Frequently Asked Questions

What is the difference between an inline pinion and a sidewinder pinion?

The difference lies in the orientation of the motor. In an inline configuration, the motor is arranged longitudinally (in line with the car), and the pinion transmits power directly to the rear axle crown gear. In a sidewinder configuration, the motor is transverse to the rear axle. Using the correct pinion for each setup is essential for proper meshing.

Which Slot.it crown gears are compatible with these pinions?

They are compatible with Slot.it crown gears of the same module designed for inline transmissions. Check the Slot.it catalogue to identify the appropriate crown gear based on the gear ratio you are looking for.

Why does the pack include 2 units?

Slot.it sells these pinions in packs of 2 units, which is practical for having a spare on hand as well as for preparing several cars at the same time with the same transmission setup.

What gear ratio do I achieve with a 9-tooth pinion?

The gear ratio depends on the pinion-crown combination. By dividing the number of teeth on the crown gear by those on the pinion, you obtain the ratio. For example, with a 27-tooth crown gear and this 9-tooth pinion, the ratio would be 3:1. A higher ratio provides more torque and lower top speed; a lower ratio offers higher top speed but less acceleration.

How do I know if the pinion fits on my motor shaft?

You need to check the inner diameter of the pinion and compare it with the diameter of your motor shaft. Slot.it specifies the measurements of its pinions in its spare parts catalogue. If you have doubts, consult the motor's technical sheet or contact us before proceeding with the installation.

Slot.it SIPI09 inline pinion, 9 teeth, 5.5 mm diameter, pack of 2 units. Designed for inline motor setups in 1/32 slot car racing. Compatible with Slot.it transmission systems. Essential spare part for competitive club racing and home track tuning. Precision-made for consistent mesh and minimal power loss.