The Acerbis X-Grip frame guard is made from a dual-injected mold, and that's where the key is. The outer plastic is durable polycarbonate – that's what allows it to serve as an excellent frame guard. Meanwhile, the inner plastic is much more pliable (though still durable), and this is the piece that offers the incredible grip. Together, they create a frame guard that will make both bike and rider happy.
