The effect of rollover protection systems and trailers on quad bike stability

Abstract

ABSTRACT Quad bikes are light-weight vehicles which are used for transportation of personnel, equipment, and material in forestry operations such as planning, logging, planting, and fire-fighting. With increased quad bike usage, serious injuries have become an increasing concern. The most common forms of severe incidents occur when a quad bike loses stability, causing injuries as it rolls over the rider trapped beneath. The risk of injuries during a rollover incident can be decreased by equipping the vehicle with rollover protection systems (ROPS), but since ROPS tend to decrease the stability of quad bikes, their use can be a trade-off between the risk of overturning and the outcome of any such incident. In this study, we examine the effects of approach angle, trailer load, ROPS and different hardware configurations on a quad bike’s static stability. We found that approach angle and trailer configurations influenced the vehicle’s stability, although the effect was difficult to quantify in a static environment. Furthermore, the quad bike’s stability was negatively influenced by equipping it with a heavy (44 kg) ROPS. It reduced the static stability by an average of 5.1°, while a light (14.7 kg) prototype ROPS only reduced the vehicle’s static stability by an average of 1.0°. The negative impact a ROPS has on a quad bike’s lateral stability could be effectively counteracted by increasing the quad bike’s track width. Increasing track width by less than 2% (20 mm) compensated for any negative impact that the light prototype ROPS had on the quad bike’s lateral stability.