7. Next, the triple-bellow airbags were bolted in place, above the axle tubes. Normally, a 'bag-over-axle setup offers a rough ride compared to one where the 'bags are mounted further forward of the axle, directly on the link bars. But, because these are triple-bellow 'bags, they offer more air volume and require less air pressure to lift the truck to the same height as a standard double-bellow 'bag. This all works out to a smooth ride, even when pumping the 'bags up with enough air to clear 22-inch wheels.