Make sure your chainrings are tight and secure with these aluminum chainring bolts. They are specially designed for 4-arm cranks, so you will never have to worry about things coming loose or breaking again. Looking to upgrade your bike? Try out our ALUGEAR chainring nuts and bolts. These are CNC-machined from aluminum and have a sleek design that is perfect for any mountain, road or hybrid bike. They feature a 4mm hex on the bolt and a 6mm hex on the nut, eliminating the need for a wrench