A few years ago the main racing category here in Australia went from a class with many tyre suppliers to a class with a single control tyre. This left many teams disadvantaged as a result of not having ever tested with the remaining tyre. An interesting discussion at the time was the fact that these teams needed to not only tune the suspension to allow for the different grip characteristics, but also to the spring rate of the tyre. A bad combination could set up nodes in a standing wave causing the vertical wheel motion to alter during a single sweep.