Riding comfort evaluation and stress for road handbike vehicle

Handbikes (HB) are a new type of bicycle for disabled people. This vehicle has three wheels and the pedaling movement is made by the arms instead of the legs. The first pure sports equipment was developed in 1999 in the USA and its particular performance motivates wheelchair drivers to look at cycling. Nowadays, the HB is not only a new sport with many competitions all over the world, but also a great opportunity for all disabled people to do sport and movement and still ride a bicycle. In the year 2000 an Handbike technical commission was founded which coordinates all the races, events and tours. Road Cycling was introduced as a Paralympic sport at the Stoke Mandeville/New York 1984 Paralympics. Paralympic Cycling was originally developed as a sport for blind athletes, who first competed using tandem bicycles. Technological advancements have since opened up the sport to a wider range of athletes; as a result, it is now the third largest sport on the Paralympic programme. H1–H4 are the categories where athletes use a handcycle. The lower the athlete’s class number, the greater the impact of their impairment on their ability to compete. In the Paralympic Games taken place in London in the 2012 the Italian disabled athlete Zanardi won the gold medal on the course at Brands Hatch. Until now, there are very few works in literature about this new kind of bicycle and their athletes. Generally HB races are performed on street circuit and the drivers are affected by high level of stress. This paper deals with the preliminary research of a special project on the design and realization of innovative cycling road devices focused both on the HB either on the disabled athlete. The main target of the paper is to investigate and find out the dynamic behavior of the HB and the force and vibration feedbacks received by the driver along a race track with different uneven road profiles. On purpose special electronic instrumentation device allows to detect acceleration and angular velocity signals of the vehicle and comfort level of the driver through sensors fixed on the seat. Signals coming from two measurement inertial units (one positioned on the frame and the other one attached to the seat of the HB) and from a matrix of force sensing resistors positioned on the seat are collected by means of an acquisition device. Data are stored on a memory card which can be extracted at the end of the trial for an offline processing. Finally, the experimental analysis of the main kinematical and dynamical parameters allows to characterize the behavior of the HB in relationship with different kind of tarmac, concrete or generic street surface in order to study new solutions for comfortable and performance vehicle.