I’m alright jack

If there is one thing guaranteed to start a bar room brawl with racecar performance engineers, it’s the subject of suspension geometry. Particularly when you mention force application points vs kinematic roll centre.

Of all the articles I have written for Racecar Engineering, by far and away the ones that have generated the most interest are those concerning suspension geometry. However, if there is one big blind spot on the subject, it is jacking forces. You see the term thrown about, but there is a lot of mystery about what it actually is. That is what I will be discussing in this article.

Jacking forces come from the vertical component of the suspension geometry linkages that are applied to the sprung mass

To kick things off, I want to start by way of an apology. I really didn’t take this subject seriously until about 2013