BBS Multi Piece Wheel Bolt Selection Guide
Rebuilding BBS multi-piece wheels is one of those jobs where small details make a massive difference. Among those details, assembly bolts are the single most critical component holding the entire wheel together. Choosing the wrong bolt size, length, or specification can lead to improper clamping force, air leaks, or in worst cases, structural failure.
Unlike generic split-rim wheels, BBS used multiple bolt standards across different generations and models. The differences are not random—they reflect engineering changes in load capacity, wheel diameter, and construction method (2-piece vs 3-piece).
This guide breaks down exactly which bolts BBS models uses, how to identify them, and how to choose the correct length when rebuilding or modifying your wheels.
BBS RS (3-Piece) Wheel Bolts
The original BBS RS is a true 3-piece wheel consisting of a center, inner barrel, and outer lip. Most RS wheels—especially in 15” and 16” sizes—use M6 assembly bolts.
These bolts typically feature:
- M7 diameter with 1.0 mm thread pitch
- Lengths between ~32 mm, depending on lip thickness
- 12-point heads and high-tensile (10.9) steel construction (13mm Bolt Head Diameter)
BBS RM (2-Piece) Wheel Bolts
The BBS RM is essentially a simplified RS—a 2-piece wheel with a one-piece center and removable outer lip.
Despite the construction difference, RM wheels still use:
- M7 bolts (same thread pitch as RS: 1.0 mm)
- Typically shorter lengths (~24 mm) due to reduced stack thickness
Because there’s no separate inner barrel, the total clamping thickness is lower. That’s why RM bolts are usually shorter than RS bolts.
From a rebuild perspective:
- RM hardware is easier to work with
- But more sensitive to over-torque (because fewer components are being clamped)
