Standard suspensions on trailer and fifth-wheel chassis have looked the same since they first hit the road. Typical configurations enlist leaf springs, shackles and equalizers to tie the axles to the frame. In the last few years, computer technology has helped raise the bar using sophisticated programs that have the capability of simulating the actual movement of components. This allows for detailed ¡°testing¡± without the need of physically fabricating parts and running trial and error stints on the road. The result has been a number of advanced suspension components that improve ride and ps.