Laboratory Evaluation of Water Bottle Cages Equivalent Stiffness

The holding capability of bottle cages can be compromised by jumps in mountain bike gravity disciplines or by terrain irregularities in road or gravel biking, which may lead to bottles falling out. The secure holding of a bottle depends on factors such as the type of bottle cage (i.e. its material and shape), the specific bottle being used, the presence of dust, water, or mud between the bottle cage and the bottle, and the amount of liquid in the bottle itself. This study aims to establish a testing setup and protocol for comparing bottle holders efficiently. The setup includes an adjustable aluminum frame that simulates various bottle inclinations, mounted on an electrodynamic shaker. The shaker can impose different excitations such as broad-band noise that reproduces the vibration measured in specific conditions, harmonic vibration, or shocks. Due to the non-linear response of the bottle/bottle cage system, several tests may lead to different results. This paper presents a case study where a set of 11 bottle cages was tested. Metrics to evaluate the performance of bottle cages are proposed and compared to the subjective evaluation of the experts given during the experimental tests.