I joined the team at Trust Performance in June of 2017, after finishing my undergraduate degree in Mechanical Engineering. Two long-held interests of mine are suspension damper technology and linkage/mechanism design. So, this was a unusually good fit for my first post-college project.

Our goal with the Message was to address endemic issues in the two-wheel front suspension world. Telescoping fork designs (what most imagine when thinking of a suspension fork) are technologically mature and ubiquitous. Despite being highly refined, however, telescoping forks have some inherent design issues.

The most glaring issue regards steering stability. Without getting too far into the weeds, we can say that telescoping forks generally have more stable steering characteristics at low speed than they do at high speed. Ideally, the opposite would be true - lower stability during slow speed technical sections, and higher stability during faster “wide open” sections of trail. Unfortunately, the kinematics of a telescoping fork prevent it from overcoming this issue.

To address the stability issue, we used a mechanical linkage which allowed us to dynamically change fork offset throughout the range of suspension travel. By decreasing fork offset, we were able to achieve a much more consistent mechanical trail value throughout the range of fork travel. Mechanical Trail is one of the primary quantifiable characteristics of steering geometry, and in a nutshell it is determined by head-tube angle (AKA rake angle), wheel diameter, and fork offset. Generally speaking, decreasing fork offset will increase mechanical trail. The head-tube angle will become steeper as a fork compresses (assuming no compression of the rear suspension). The effect of a steepening head-tube is a decreased mechanical trail. So, by dynamically decreasing fork offset through the travel, we are able to counteract the loss of mechanical trail that results from a steeper head-tube angle.