Suspension geometry is an essential aspect of any vehicle’s design, and it plays a critical role in its performance, handling, and ride quality. In this article, we’ll dive into the basics of suspension geometry, including its fundamental concepts, terminology, and components.

Introduction
In this section, we’ll briefly introduce suspension geometry and its importance. Suspension geometry is a crucial aspect of any vehicle’s design and can greatly affect its handling and ride quality. Understanding suspension geometry can help you tune your vehicle’s suspension for optimal performance.
What is Suspension Geometry?
Suspension geometry refers to the position and orientation of a vehicle’s suspension components. It is defined by the location of each pivot point in 3D space, and it affects the kinematics of the suspension, which is the motion of each component as the suspension moves through its travel.
Chassis Pickup Points and Joints
The chassis pickup points are where each suspension component attaches to the chassis. Each pickup point has a joint that locates the position of each suspension component and allows it to rotate as the suspension moves.
Suspension Arms and Members
Suspension arms, also known as members, are attached at one end to the chassis pickup points. They can include upper and lower wishbones, suspension links, or the upper part of the strut in a MacPherson strut.
Steering Rack and Links
The steering rack and links form part of the suspension geometry. The rack dictates the inner pivot point of the toe link, with the toe link itself forming one of the suspension arms.
Upright
The upright houses the wheel bearings and provides a place for the brake caliper to mount. Each end of the suspension arm links is attached to the upright.
Pivot Points
Each suspension arm and link has its own pivot point on the upright, similar to the chassis pickup points. Modifying the position of these points modifies the suspension geometry.
Kinematics of Suspension
The kinematics of the suspension refers to the way the angles and positions of each suspension component change as the suspension moves through its travel.
Compliance
Compliance refers to the flex that we see in all suspension parts as they cycle through their travel. While it is calculated and measured in professional motorsport, we’ll be treating suspension parts as though they are rigid for our purposes.
Bump Steer
Bump steer is the change in toe angle of a wheel as the suspension moves through its travel. It occurs due to the combination of different arcs in the steering arms, control arms, and upright travel.
Summary of Suspension Geometry
Suspension geometry describes the position in space of each pivot point for each part of the suspension, while kinematics describes the resulting motion of each part of the suspension. It’s essential to understand that only the strut has linear motion, while everything else moves in an arc.
Conclusion
In conclusion, suspension geometry is a critical aspect of any vehicle’s design, and understanding its fundamentals is crucial for optimal performance, handling, and ride quality. By grasping the basics of suspension geometry, you can better tune your vehicle’s suspension to suit your needs.
FAQs
Here are some frequently asked questions about suspension geometry:
Q1. Why is suspension geometry important?
A1. Suspension geometry affects a vehicle’s handling, ride quality, and performance. By understanding suspension geometry, you can optimize your vehicle’s suspension for your specific needs.
Q2. What are some common suspension types?
A2. Some common suspension types include double wishbone, MacPherson strut, and multi-link suspensions.
Q3. Can suspension geometry be adjusted?
A3. Yes, suspension geometry can be adjusted by modifying the position of the pivot points or changing suspension components.
Q4. How does suspension geometry affect tire wear?
A4. Improper suspension geometry can cause uneven tire wear and shorten tire life.
Q5. Can suspension geometry affect fuel economy?
A5. Yes, suspension geometry can affect fuel economy by affecting a vehicle’s aerodynamics and rolling resistance.
Suspension geometry is a complex topic, and understanding its fundamentals is crucial for optimal vehicle performance. By familiarizing yourself with the basics of suspension geometry, you can optimize your vehicle’s suspension for your specific needs and ensure a comfortable and safe driving experience.
Source
- “Suspension Geometry Explained” by Racecar Engineering: This article provides a comprehensive overview of suspension geometry and its impact on vehicle handling and performance. https://www.racecar-engineering.com/articles/suspension-geometry-explained/
- “Understanding Suspension Geometry” by Hot Rod Network: This article provides a detailed explanation of the various components of suspension geometry and how they interact with each other. https://www.hotrod.com/articles/understanding-suspension-geometry/
- “Suspension Tuning: Understanding Geometry Basics” by Super Street Online: This article provides a beginner-friendly introduction to suspension geometry and its importance in suspension tuning. https://www.superstreetonline.com/how-to/chassis-suspension/1806-suspension-tuning-understanding-geometry-basics/