Study and dynamic simulation of Brain mountain bike rear suspensions

This thesis project aims to study a particular model of rear suspension for mountain bikes called Brain, developed by the brand Specialized. Unlike traditional mountain bike suspensions, the Brain system was designed to solve a common issue that cyclists experience when riding a full-suspension bicycle: the loss of pedalling performance caused by unnecessary compression of the rear shock absorber. The system can distinguish inputs from the ground (i.e. ground vibrations) and from the cyclist, and it adjusts the suspension accordingly to allow greater pedalling efficiency and comfort. To do so, the Brain system adjusts the rear shock absorber's suspension based on the riding conditions by activating or deactivating a valve system, which controls the activation of the rear suspension. Therefore, the main advantages of the Brain system are that it acts only when necessary and automatically, without the rider’s intervention, and it is a purely mechanical system, which does not include any electronic control system. In this project, dynamic simulations of the Brain suspension are carried out using Adams software, comparing the performance of the Brain suspension to that of a traditional mountain bike suspension.