In order to validate prediction models of wheel sqeal, a two-disk rolling contact test rig has ben developed to investigate fundamental behaviour. This test rig has been modified to allow for a range of angles of attack to be set and measured accurately, with a relative error about 1%. On the other hand, in order to perfom a controlled investigation of the effects of humidity on wheel squeal, a humidity control system was set up in the enclosure of the test rig. Squel noise was recorded at the different angle of attack, rolling speed and relative humidity, and the analysed results not only indicate the effect of these parameters initially, but also correlate well with results from modal test and FEA. Furtermore, the test rig was retrofitted to measure the lateral force at the rolling contact patch with strain gauges on leaf springs
