The lean angles of motorcycles driving through a sequence of curves were measured by means of a GPS logger. All participants had to ride on a standardised pre-set route, about 20 km long. From the logged GPS data – speed, geographic coordinates and time – the motorcycle lean angles were calculated by means of a mathematical model that accounted for individual motorcycle parameters, especially the tyre width.
The test route had 39 curves whose radii were evaluated by means of aerial photographs. The lean angles at the curves’ vertices were derived from the GPS data and grouped into radii categories – first without any additional criteria and in a second step depending on the characteristics of the rider and the motorcycle. Typical rider characteristics are the personal risk-taking behaviour and the riding experience.
The results show that the standard values published in 1981 do not reflect the achievements of modern motorcycle technology. Furthermore, a categorisation by the driving radius is highly recommendable.