A tag axle suspension system can include a tire and at least one hanger bracket pivotable relative to a vehicle frame to deployed and lifted configurations. In the lifted configuration, the tire can be a lowest component of the suspension system, and can be a first component to engage a road surface. A tag axle suspension system can include an air spring and a travel limit device that limits compression of the air spring in a lifted configuration of a hanger bracket. A tag axle suspension system can include an axle, a suspension arm pivotably connected between a hanger bracket and the axle, and a travel limit device that limits displacement of the suspension arm in a lifted configuration of the hanger bracket. The travel limit device can limit displacement of the axle toward an air spring support in the lifted configuration of the hanger bracket.