The present invention relates to a method and apparatus for predicting tire traction characteristics of tread compounds. 
Although compounders can predict, to a certain extent, the properties of specific rubber compounds, the properties ultimately can only be determined by testing.  In the past, when the compound was a tread compound, traction properties could only be determined by building a tire and subjecting the tire to various traction tests. 
Since tire building is very time consuming and expensive, especially in small lots, in the past, traction testing only served to determine if the properties were within acceptable ranges for given conditions.  It was very difficult to fully optimize a tread compound to optimize traction properties. 
There are known in the art a number of tests for measuring the friction properties of rubber.  Friction properties, however, do not correlate well with traction properties because of the rate and frequency of deformation (depending on the speed of a rubber sample and the number of asperities on the traction surface) components of traction. 
It is an object of the present invention to provide a method and apparatus for using very small samples of tread compounds to determine the traction characteristics of the compounds.  Since small samples of the tread compound are used for testing, and it is not necessary to build a tire, traction characteristics can be determined very quickly and inexpensively.  Since the tread compounds can be made in small batches, a large number of compounds can be made for screening, to determine which compound has the best properties.  Also, since the testing surface in the apparatus may be changed to represent a large number of different road surfaces and different conditions, the traction properties of the compounds may be observed to determine which compound has the best traction on a specific road surface under specific conditions. 
Other objects of the invention will become apparent from the following description and claims.