Keep your drivetrain running smoothly and cut maintenance costs in half with the e*thirteen Helix Race 43-52T aluminum replacement cluster. Unlike one-piece alternatives, this component lets you replace only the worn alloy cogs, or it can be used as a backward-compatible upgrade to increase the range of an existing 9-50T steel setup. To ensure maximum durability, pair this fresh cluster with a new chain if your current one shows 0.5% or more wear.