Bicycle suspension is increasingly used to improve performance and facilitate the use of smaller wheels for folding bicycles, unwanted activation due to pedalling and braking forces can however result in energy losses. This paper presents a kinematic analysis leading to a Suspension Activation Ratio (SAR) which is the ratio of the suspension activation force to the pedalling force and its experimental verification. The SAR may be used as a performance metric to compare suspension designs and an objective function for suspension design optimization where the SAR is minimized for all possible gear ratios. Suspension geometry thus optimized shows agreement with optimal pivot positions found by empirical studies. Previous work has involved dynamic simulation and experimentation to estimate energy losses; however it is difficult to apply this analysis to rapidly evaluate different suspension designs for performance evaluation or design optimization. The kinematic design approach presented here provides the first step in suspension design which should precede dynamic design to optimize spring and damping rates.