In-field testing: road load data
Forces that act on the bicycle result from bike-rider and bike-road interactions. The magnitude and occurence depends on the user-profile and road conditions.
Bad road conditions result in vibrations and impact events on the bicycle, resulting in reduced riding comfort and unexpected high loads on the bicycle.
Stress & strain
It's the force on the bike that results in failure, cracks or fatigue damage. The stress & strain in the frame tubes and connection points should be below a safe limit.
Integration of high torque mid-frame motors stress the bicycle chain stays and rear dropout more than in normal cycling conditions. Meausuring rear-axle forces quantifies this.