STD Rim Adapter Set, Silver, for Royal Alloy GP, TG, JPS 300-350 (for mounting Vespa GTS rims)

Wheel Hub Adapter Kit ScooterTec x Scooter Center – Silver Powder-Coated – Vespa GTS Wheels for Royal Alloy GP, TG and JPS 300–350

Your Royal Alloy. Your style. Your wheels! With the silver wheel hub adapter kit from ScooterTec and Scooter Center, completely new possibilities open up for customising Royal Alloy GP, TG and JPS models with 300 to 350 cc engines. For the first time, the numerous wheel designs available for the Vespa GTS can also be used on these Royal Alloy models. Whether classic multi-spoke wheels, elegant aluminium designs or sporty 13-inch wheels – the choice extends far beyond the range previously available for Royal Alloy.

The silver version impresses with its clean, technically refined appearance. The bright surfaces of the specially developed wheel hubs harmonise particularly well with classic wheel designs, polished finishes and understated colour schemes. At the same time, they provide an attractive foundation for individual conversions featuring modern wheels or contrasting colour combinations.

A Joint Development with a Special Story

What began as an idea at the Scooter Center Open Day in spring 2026 developed into an independent technical solution in collaboration with ScooterTec from Deggendorf. The aim was to make the extensive variety of Vespa GTS wheels available for Royal Alloy vehicles while taking the specific constructional characteristics of their suspension systems into account.

The result is the first wheel hub adapter kit of its kind on the market. The specially developed components enable conversion to 12-inch or 13-inch Vespa GTS wheels while also accommodating the necessary modifications to the rear braking system and ABS system.

This project combines the expertise of two companies from the scooter scene with the desire for greater freedom in individual vehicle customisation.

Silver Wheel Hubs – High-Quality Materials and Precision Manufacturing

The two wheel hubs form the technical foundation of the conversion. They are manufactured in Germany and specifically designed for their respective mounting positions.

The rear wheel hub is made from high-strength 42CrMo4 quenched and tempered steel. This material provides the mechanical properties required for this structurally demanding component. The silver powder coating creates a uniform surface finish and emphasises its high-quality technical character.

The front wheel hub is manufactured from 6083 aluminium and is also silver powder-coated. Precision machining creates the necessary mounting and mating surfaces for installing the intended Vespa GTS wheels.

Visually, the silver version is particularly well suited to vehicles with chrome accessories, bright wheel finishes or a classic retro concept. However, it can also be combined with black, bronze or brightly painted wheels.

More Than a Wheel Adapter – A Coordinated Conversion System

Fitting different wheels to a Royal Alloy requires carefully considered modifications to several components. Particularly at the rear axle, the position of the brake disc, the mounting of the brake caliper and the operation of the ABS sensor must all be taken into account.

For this reason, the rear wheel hub is supplied fully pre-assembled. A suitable brake disc from manufacturer Braking and a specially modified ABS tone ring are already integrated into this assembly.

The front wheel hub is also prepared for installation and comes with pre-installed wheel bearings. A ByBre (Brembo) brake caliper, including brake pads, is supplied for the rear braking system. The kit also includes an adapted bracket for the rear ABS sensor, the necessary spacers and spacing washers, and a suitable banjo bolt with new sealing washers.

The individual components are engineered to work together as a system. This creates a comprehensive conversion solution in which essential parts are already prepared for installation.

From Classic to Sporty – Explore the Variety of Vespa GTS Wheels

One of the most appealing features of this adapter kit is the extensive choice of different wheels. The Vespa GTS is one of the most popular scooters for individual wheel conversions, resulting in a particularly wide range of designs, colours and sizes.

With the ScooterTec x Scooter Center kit, this selection can now also be used for Royal Alloy GP, TG and JPS models. The silver version blends especially harmoniously into classic vehicle concepts where the wheels are not merely technical components but an essential part of the overall design.

Sport-oriented conversions also benefit from the possibility of using 13-inch wheels with distinctive spoke patterns and individual colour variations.

Permitted Tyre Dimensions and Clearance

When selecting wheels and tyres, the available installation space and constructional limitations must be taken into account. In particular, the available tyre width is restricted around the front Anti-Dive suspension system.

• 12-inch wheels: Maximum front tyre width of 120 mm, for example 120/70-12
• 13-inch wheels: Maximum front tyre size of 130/60-13
• 13-inch wheels: Maximum rear tyre size of 140/60-13

For 12-inch wheels, front tyres wider than 120 mm must not be used. Depending on the actual tyre profile, wider tyres may otherwise come into contact with the Anti-Dive shock absorber mounting.

Regardless of the specified tyre size, the clearance of the selected wheel and tyre combination must be carefully checked on the vehicle.

Suitable for Royal Alloy

• Royal Alloy GP 300 and GP 350
• Royal Alloy TG 300 and TG 350
• Royal Alloy JPS 300 and JPS 350

The adapter kit is designed for conversion to 12-inch and 13-inch Vespa GTS wheels. The actual compatibility of the selected wheels and tyres, as well as the required road approval, must be checked before carrying out the conversion.

Scope of Delivery

• Front wheel hub made from 6083 aluminium, silver powder-coated, including pre-installed wheel bearings
• Rear wheel hub made from 42CrMo4 quenched and tempered steel, silver powder-coated
• Braking rear brake disc, already mounted on the wheel hub
• Modified rear ABS tone ring, already pre-assembled
• ByBre (Brembo) rear brake caliper including pre-installed brake pads
• Specially adapted bracket for the rear ABS sensor
• Required spacers and spacing washers
• Suitable banjo bolt for the brake line connection, including new sealing washers
• Additional small components required for installation

Not included: Wheels, tyres and wheel mounting bolts.

Important Installation Instructions

Installing the wheel hub adapter kit involves work on safety-critical areas of the vehicle. In addition to wheel mounting, the rear braking system and ABS system are particularly affected. The supplied installation instructions must therefore be followed carefully.

• Only M8 × 35 mm bolts with strength grade 10.9 may be used to secure the wheels. Different bolt lengths are not permitted.
• The distance between the rear ABS sensor and the modified tone ring must be 0.5–1.5 mm. The sensor must be aligned centrally with the windows of the tone ring.
• The supplied banjo bolt must be used together with the new sealing washers for the ByBre (Brembo) brake caliper. The thread pitch differs from the original version.
• After connecting the brake line, the braking system must be professionally bled and checked for leaks and correct operation.
• All threaded connections must be tightened to the specified torque values. Wheel clearance and correct ABS operation must be checked before the vehicle is put into service.

Due to the safety-critical nature of this work, we recommend that the conversion is carried out exclusively by appropriately qualified professionals.

Road Approval and Registration

The wheel hub adapter kit is supplied without ABE, TÜV approval documentation or a parts approval certificate (Teilegutachten). It does not automatically have approval for use on public roads.

For questions regarding a possible individual vehicle inspection and registration of the conversion, please contact ScooterTec Deggendorf directly. The possibility of obtaining approval for the intended wheel and tyre combination should be clarified with the responsible inspection authority before starting the conversion.

Silver Edition – Classic Elegance Meets Individual Freedom

With the silver version of the ScooterTec x Scooter Center wheel hub adapter kit, Royal Alloy owners gain a new foundation for individual wheel concepts. The combination of precision-manufactured components, high-quality materials and the extensive design variety of Vespa GTS wheels creates possibilities that were previously unavailable.

Whether you are planning a subtle retro conversion, an elegant colour combination or a sporty custom scooter, the silver wheel hubs complement a wide range of styles while allowing the chosen wheels to take centre stage.

A joint development by ScooterTec and Scooter Center, manufactured in Germany and created for everyone who wants to take their own approach to customising a Royal Alloy.

Note: The vehicle images are provided for installation and styling illustration purposes only. The wheels and tyres shown are not included in the scope of delivery.