Most people put too little pressure in road tires and too much pressure in off-road rubber. Road tires usually take from 95 to 125 pounds per square inch (psi). If you weigh less than 150 pounds, go toward the lower end and vice versa. For mountain tires intended for off-road use, a good range is from 35 to 45 pounds. Use the same rule for weight. With off-road rubber, you’ll find that less air means a softer ride and improved control because the tire has a larger footprint on the trail.