The Park Tool Chain Checker CC-2 is a great device for determining if you need to replace your chain or rear cog, by accurately measuring the wear and stretch of any chain.

With most manufacturers recommending replacing your chain at 0.75% stretch, the Park Tool chain checker will quickly and precisely let you know if you are over or under. As overworn chains can cause poor shifting and uneven drivetrain wear, having an accurate gauge to hand won't just save your chain, but can also save the full functionality of your bike. 

Reading wear from 0.25% to 1%, the CC-2 is compatible with 9/10/11-Speed chains and measures the stretch by simply inserting the pins between two links and pressing the swing-arm gauge tight to read your accurate reading in the gauge window.

(Note: For 9/10-speed chains, replace the chain at or before the 0.75% reading, and for 11/12-speeds, replace before the 0.5% reading. Always check with the manufacturer for any specific replacement instructions and recommendations.)

About the Park Tool brand

Park Tool has been manufacturing bicycle specific tools since 1963. Based out of St. Paul Minnesota, they are the world's largest bicycle tool manufacturer. A long-term dedication to quality and innovation, Park Tool is the first choice of professional and home bicycle mechanics around the world. Their vision is shaped by more than 40 years of experience in the bicycle industry, beginning with retail stores. There they learned first hand the changing needs of quality bicycle repair and maintenance.