Backspacing, 5 x 5 1/2 in, 5 x 139.70mm Bolt Pattern, Each - Bart Wheels Super Trucker silver wheels are designed for 2WD or 4WD trucks and are built with high-strength 950X steel center material and a roll-formed rim shell to handle off-road and over-the-road use with ease. They are available in a choice of sizes and backspacings.