Z27 x 16 Ø angular Purple Crown - Inverted

The inverted angular crown gear from Sloting Plus for those who fine-tune every tenth on track

The Z27 x 16 Ø Inverted Purple Angular Crown (SP072427) from Sloting Plus is a precision transmission component designed for anglewinder setups where space, weight, and gear accuracy make the difference between winning and missing the podium.

Technical specifications

• Number of teeth: 27 (Z27)
• Diameter: 16 mm
• Total thickness: 4.25 mm
• Material: Lightweight duralumin
• Weight: 0.6 g
• Axle compatibility: 2.38 mm (3/32'')
• Fixing: M2.5 x 3 mm allen grub screw
• Configuration: Angular gear — inverted standard pitch
• Identifying colour: Purple
• Contents: Bag with 1 unit

Function and performance

In an anglewinder transmission, the crown gear is the link where the motor's power is converted into wheel speed. A poorly chosen crown or one with inadequate tolerances generates vibration, noise, and loss of efficiency. The lightweight duralumin used by Sloting Plus in this reference minimizes rotating weight, resulting in a more responsive acceleration and less inertia during braking.

The inverted pitch is key: it allows the rear axle's rotation direction to be reversed compared to the standard, which is common in certain anglewinder chassis where the motor's position or the assembly's geometry requires it. Before installation, it is advisable to check that the motor pinion has a compatible (also inverted) pitch to ensure a clean and quiet engagement.

Compatibility and installation

This crown is designed for rear axles of 2.38 mm (3/32''), the most widely used standard in competitive slot racing. The fixing with an M2.5 allen grub screw allows for secure tightening without damaging the axle and facilitates quick changes between tuning sessions.

Sloting Plus's colour coding system — purple for this tooth ratio — speeds up identification in the workshop when working with multiple gear ratios at once. A small advantage but one that makes a difference during quick preparations before a heat.

Installation and preparation

• Check that the motor pinion is also of inverted pitch before installation.
• Clean the axle with a dry cloth before placing the crown to ensure perfect centring.
• Tighten the allen grub screw with the appropriate tool (M2.5) without over-tightening; duralumin holds well, but over-tightening can deform the housing.
• Check the play of the engagement with the pinion: there should be a slight axial play without forced contact.
• Apply a minimal amount of specific slot gear lubricant to the tooth flanks.

Common mistakes

• Mixing standard pitch and inverted pitch: this is the most common mistake. An inverted crown requires an inverted pinion; if they do not match, the gear will make noise, wear quickly, and the transmission will lose efficiency.
• Ignoring rotating weight: a crown that is heavier than necessary penalises the car's response. The goal is always to achieve the lowest possible mass with sufficient rigidity.
• Not checking centring: a poorly centred crown on the axle causes vibration at high speeds and may end up loosening.

Frequently asked questions

What is the difference between a standard crown and an inverted one?

The inverted pitch reverses the tooth angle compared to the standard, changing the axial push direction in the engagement. It is used in anglewinder setups where the motor's arrangement requires reversing the rear axle's rotation direction or where the chassis geometry demands it. They are not interchangeable with standard pitch crowns.

Which pinions is this crown compatible with?

It should be used with inverted pitch pinions that fit the corresponding motor axle. Sloting Plus offers inverted pitch pinions in various references to complete the gear ratio. Check the pinion reference based on the motor you use.

Is it valid for any 3/32'' axle?

Yes, as long as the axle is 2.38 mm (3/32''). This is the most common diameter in competitive slot rear axles, so compatibility is broad with chassis from multiple manufacturers.

How much does it weigh and why does it matter in competition?

It weighs 0.6 grams. In competitive slot racing, reducing rotating mass improves acceleration and response to speed changes. A heavier crown adds inertia: the car takes longer to accelerate and longer to brake. For the same gear ratio, the lighter crown that offers the necessary strength is always preferred.

What allen key do I need for the fixing grub screw?

The grub screw is M2.5 x 3 mm, so you need a 1.5 mm allen key, which is the standard for M2.5 screws in slot. It is advisable to use a good quality key to avoid rounding the head.

Does it come with the fixing grub screw included?

Yes, the description indicates that it includes an M2.5 x 3 mm allen grub screw in the same bag along with the crown.

The Sloting Plus SP072427 is an anglewinder inverted-pass crown gear, Z27, 16 mm diameter, made from lightweight duralumin. Weighing just 0.6 g, it fits 3/32'' (2.38 mm) axles and is secured with an M2.5 allen grub screw. Designed for competitive slot car racing, it reduces rotational mass and ensures precise power transfer in anglewinder setups. Compatible with inverted-pass pinions from Sloting Plus and other leading slot car brands. Ideal for club racers and serious hobbyists looking to fine-tune their transmission ratio.