Chains and chain rings at economic prices from starbike.com, the bicycle online shop

Bicycle chains and chain rings are an integral part of the bicycle drivetrain.

The chainrings are mounted on the cranks and create the gear ratio in combination with the cassette/cog on the rear. There are single, double or triple chainring setups. Gear hubs (like the Rohloff Speedhub) and singlespeed bikes have only a single chainring.

On the contrary cassette-operated shifting system come with 2 or 3 chainrings.

The chain is moved from one chainring to another with the front derailleur. This enables cyclists to change the gear ratio to their individual preferences in ascents and descents.