Lippmann, S., Piccin, W., and Baker, T., "Enveloping Characteristics of Truck Tires — A Laboratory Evaluation," SAE Technical Paper 650184, 1965, doi:10.4271/650184.
The paper describes the enveloping properties of truck tires as consisting of two components of force, one in the vertical direction and another in the direction of travel. The responses to irregular surfaces are mathematically accountable in terms of the response to a step in pavement elevation. Tires may therefore be readily characterized through their reactions to step functions. Curves display the differences in enveloping properties available in the 10.00–20 size on the open market.