To be worn correctly a helmet must be comfortable to wear, functional in use and easy to put on and remove. The helmets' comfort levels are assessed in terms of their ability to:
Helmet fit was assessed by at least five people with head circumferences between 57 and 58 cm. Each assessor tried an appropriately sized helmet on for several minutes and then someone else tried to roll the helmet off and measured the roll off force. After trying the helmet on the assessors analysed the helmet against a set of criteria.
The helmet's ability to reduce noise, to minimise the wind resistance and to encourage ventilation inside the helmet was assessed in a wind tunnel at a simulated riding speed of 100 km/h. The helmet was fitted on a mannequin designed for acoustic measurement. The mannequin was equipped with a specially designed microphone placed inside one of the mannequin's pinnas (ears). The wind resistance was measured using the force plate which is part of the wind tunnel and the ventilation was measured by measuring the pressure drop on the face and crown areas of the mannequin.