lt's important to understand that with a suspension system, the number of wheels and the number or fulcrums differ. An unsuspended axle provides two fulcrums (one at each wheel), while a suspended axle provides just one, at the point of its attachment to the vehicle. For instance, a vehicle with four wheels can have one suspended and one unsuspended axle to get three fulcrums (Figure 15-3) A six-wheeled vehicle will also have three fulcrums if all three axles are suspended (Figure 15-5)