BMX Race Chainrings 4 Bolt | Rollout Calculator

Cranks have either four or five bolt holes for chainring attachment. This is also known or often called the spider. A 4 bolt chainring must be ran with a crank that has 4 bolts. It will not work on cranks with 5 bolts and vice-versa. Four bolt Chainrings are popular with full size bmx racing bike setups, 5 bolt generally found on smaller bikes with shorter cranks.