A field experiment was carried out to evaluate the conditions for the appeareance of the power hope phenomenon. It consists in low frequency vibrations and great amplitude. This physical phenomenon is very common in FWA tractors, mainly with unequal tires diameter in front and rear axle. To promote power hope, different weight distribution conditions, different tire pressure and different drawbar force were used. Power hope occurence conditions were determined using simple methodology, which uses tire radio in the calculations.
front wheel assist; power hope; tractors