CENTRAL ALUMINIUM PULLEY 27T

Transmission with Criteria: the 27T Aluminium Central Pulley from 3Racing

In any setup where belt or chain transmission is key, the quality of the central pulley makes the difference between smooth, predictable response and performance losses that accumulate lap after lap. The 27T Aluminium Central Pulley from 3Racing (ref. 3RAC-3PY/27) is a machined aluminium piece designed for those who do not want compromises in the drivetrain.

Main Features

• Material: machined aluminium, with the weight reduction that this implies compared to the original plastic versions.
• Number of Teeth: 27T, a common configuration in transmission trains of competitive RC models and tuning setups.
• Reference: 3RAC-3PY/27, from the spare parts and optional catalogue of 3Racing.
• Finish: characteristic of 3Racing's anodised aluminium, combining surface protection with a refined appearance.

Function and Performance

The central pulley is the transmission link that connects the motor to the output shaft via the belt or chain drive. Using an aluminium piece instead of the original plastic version offers several practical advantages: greater stiffness under lateral loads, less deformation under heat, and, in most cases, a similar or even lower weight than reinforced plastic, depending on the wall thickness of the original component.

The 27 teeth determine the final gear ratio along with the motor pulley and the output pulley. Before fitting this piece, ensure that the tooth combination is correct for the ratio you seek in your setup.

Compatibility and Fitting

This pulley is designed for models compatible with the 3Racing transmission system. Check your chassis manual or the manufacturer's documentation to confirm that the belt pitch, inner diameter, and number of teeth match your configuration before fitting. A small incompatibility in the belt pitch can cause vibrations or premature wear.

Tuning Recommendations

• Check the belt tension after fitting: neither too loose (it will slip) nor too tight (it will load the bearings).
• Apply a minimal amount of specific belt lubricant or leave it dry according to the chassis manufacturer's instructions.
• Check the alignment of the pulley with respect to the shaft: a small lateral deviation causes uneven wear on the belt and loss of efficiency.
• If you combine this pulley with other optional aluminium components, consider the set of tolerances to avoid accumulated play.

Frequently Asked Questions

Which models is the 3RAC-3PY/27 compatible with?

This pulley is part of the optional and spare parts catalogue of 3Racing. Compatibility depends on the specific chassis it is designed for. Check the reference in your model's documentation or contact us if you have questions about your specific application.

What real advantage does aluminium have over the original plastic?

Aluminium offers greater structural stiffness, does not deform under heat, and withstands lateral impacts better. In competition, this translates to a more consistent transmission throughout a prolonged session.

Are 27 teeth a standard measure?

It is a very common number of teeth in transmission trains of 1/10 and 1/12 scale RC models, although it is always necessary to verify that it matches the belt pitch of your chassis and with the other pulleys in the set.

Do I need special tools for fitting?

Generally, standard RC modelling tools (Allen keys of the appropriate size for the fixing screw) are sufficient. Consult the chassis manual for the recommended torque and avoid over-tightening on aluminium.

Can it be combined with other aluminium options from 3Racing?

Yes, 3Racing designs its options to be compatible with each other within the same chassis line. However, when combining several optional parts, it is advisable to check the set of tolerances to ensure optimal operation.

The 3RAC-3PY/27 is a 27-tooth aluminium central pulley from 3Racing, engineered for RC competition builds where drivetrain precision and weight saving matter. A direct upgrade over stock plastic pulleys, it delivers improved stiffness and consistent power transfer across the belt drive system. Compatible with 3Racing chassis lines — always verify belt pitch and shaft diameter before fitting. A straightforward yet effective tuning part for serious builders looking to refine every link in the drivetrain.

Information Not Found

It has not been possible to reliably confirm the exact chassis models compatible with this reference or the inner diameter of the pulley. If you need this data for your fitting, we recommend contacting us directly before placing your order.