BBS RS Centre Cap Assembly and Installation Guide
BBS RS wheels are among the most recognisable multi-piece wheels produced by BBS. Their combination of a mesh centre, exposed assembly bolts, removable waffle plate and threaded hexagon became a defining wheel design of the 1980s and 1990s and remains particularly popular on classic BMW, Volkswagen, Mercedes-Benz and Porsche builds.
Unlike many later BBS wheels that use clip-in centre caps, the classic BBS RS design uses a separate waffle plate secured by a threaded centre hexagon. This makes the centre assembly relatively simple to install while also allowing individual components to be replaced or mixed with compatible original BBS parts.
This guide covers installation of Mod-ing replacement centre caps for compatible BBS RS wheels, including both full-height and half-height hexagon versions.
Parts Overview
The BBS RS centre cap assembly is considerably simpler than some later BBS centre-cap designs.
The complete assembly consists of:
- Waffle plate
- Threaded hexagon
- Centre emblem or emblem holder
Two different hexagon profiles are available:
Both versions use the same basic installation method, with the choice depending primarily on the desired appearance and wheel application.
An optional centre-cap wrench can also be used to make tightening and removal of the hexagon easier.
Step 1 – Position the Waffle Plate
Begin by placing the waffle plate into the centre of the wheel.
Make sure the plate is correctly seated against the wheel before installing the hexagon. It should sit evenly around its complete circumference without rocking or catching on the wheel centre.
Do not force the plate into position. If it does not sit correctly, remove it and check that both the wheel mounting surface and rear of the waffle plate are clean and free from dirt or other obstructions.
Step 2 – Choose and Install the Hexagon
The Mod-ing BBS RS centre cap is available with two different hexagon profiles.
The full-height hexagon provides the taller, more pronounced centre profile, while the half-height hexagon offers a lower-profile appearance. We offer both versions with 72 mm and 58 mm threads.
Compare versions and select the design appropriate for your wheels and preferred appearance.
The installation procedure is the same for either version.
Start threading the hexagon by hand.
It should engage smoothly and turn without excessive resistance. If the hexagon immediately becomes tight or begins threading at an angle, remove it and start again. Never use a wrench to force incorrectly engaged threads.
Continue tightening until the hexagon secures the waffle plate firmly against the wheel.
The hexagon can be tightened by hand, although the optional Mod-ing centre-cap wrench provides additional leverage and makes both installation and later removal considerably easier.
Do not overtighten the hexagon. It only needs to be sufficiently tight to hold the waffle plate securely in position.
Step 3 – Choose and Install the Centre Emblem
There are two ways to finish the centre of the hexagon.
For the traditional BBS appearance, a compatible three-prong BBS centre emblem can be installed directly into the hexagon.
Alternatively, Mod-ing hexagons are supplied with a black three-prong blank emblem holder. This allows a flat adhesive emblem to be fitted instead.
The blank holder is particularly useful when fitting a BMW roundel or another custom sticker-style emblem while retaining the standard three-prong mounting system.
If using the blank emblem holder, first clean its front surface and allow it to dry.
Apply the chosen sticker emblem centrally to the holder and press it firmly into position.
The complete holder can then be fitted into the hexagon using its three retaining prongs.
If using a standard three-prong BBS emblem, simply align the three prongs with the corresponding openings in the hexagon.
Press the emblem evenly into position until it is securely seated.
Final Inspection
Before driving, inspect the complete centre cap assembly.
Check that:
- The waffle plate sits evenly against the wheel.
- The threaded hexagon is correctly engaged.
- The hexagon securely retains the waffle plate.
- The centre emblem or emblem holder is fully seated.
- Nothing moves or rattles when lightly checked by hand.
It is good practice to inspect the centre caps again after the first drive, particularly after fitting newly refinished wheels or new centre-cap components.
Installation Tips
Always start the hexagon by hand before using the centre-cap wrench. This makes it much easier to feel whether the threads have engaged correctly and helps prevent cross-threading.
Keep the wheel and waffle-plate contact surfaces clean. Dirt trapped underneath the plate can prevent it from sitting correctly and may damage freshly refinished surfaces.
Do not use impact tools to tighten or remove the centre hexagon. Hand tools provide more than enough leverage and greatly reduce the risk of damaging the threads or visible surfaces.
When using an adhesive BMW or custom emblem, clean the blank emblem holder thoroughly before application. Wax, polish or grease on the surface can considerably reduce adhesive strength.
With only a waffle plate, threaded hexagon and emblem required, the classic BBS RS centre cap remains one of the simplest BBS centre systems to assemble and maintain while providing the distinctive appearance that has become synonymous with BBS RS wheels.
Video Tutorial
If you would rather follow the installation visually, the video below takes you through the complete centre cap assembly from start to finish. It covers fitting and aligning the adapter and waffle plate, securing the mounting screws, threading in the hexagon and installing the centre emblem.
You can use the step-by-step instructions below as a reference while working on your wheels.