Never go flat again. Flat-free means hassle-free. Convert into riding lawn mower wheels that won't deflate after several turns. Solid core tires offer the best performance without the hefty cost. Replacing the bushings is also straightforward. You just need to lay the wheel on its side and using a screwdriver or punch, tap the outer bushing through the hole on the inner bushing. Reverse the wheel and tap the other bushing. You can then tap the new bushing in place. There are two main materials used in flat-free tires: rubber and polyurethane. Each has its own advantages. Both materials provide a smooth ride comparable to that of air-filled pneumatic wheels. But solid polyurethane foam lawn mower tires have several advantages over rubber tires. PU wheels are lighter but have a harder tread with the addition of higher water, UV, cut, tear, compression, and abrasion resistance. Check the part number for your riding lawn mower's wheels or check the stamped wheel size on the wheels' sidewall. To ensure that your existing wheels use the same bushing size, measure the inside diameter of the bushing or the outside diameter of the axle. To determine the hub length, measure the distance between both ends of the bearing/bushing. Aside from measuring the size of the bushing and hub length, you also need to determine if your lawn mower wheels have a centered or offset hub. Centered hubs are symmetrical, with both hub sides sticking out at the same distance. Convenience and performance, that's what everyone expects from a zero-turn riding lawn mower. Don't let a set of constantly flat front wheels destroy the efficiency of your mower. With a Marastar flat-free tire, you'll enjoy not only the convenience of a smooth ride but also big savings.