Use Code MEMORIALDAY20 for 20% Off One Full-Price Item

Detail Images

  • Park Tool - Chainring Diameter Gauge - One Color

Current Color

  • Park Tool - Chainring Diameter Gauge - One Color

Park Tool Chainring Diameter Gauge

sale $34.15 $35.955% Off

Free 2-Day shipping on orders over $50. Learn More

Select style & size:

Select options
  • Select options
    • One Color, One Size
      sale $34.15

    Be the first to review

    Details

    Knowing Your Crank's BCD has Never Been Easier.

    When it comes time to replace a worn out chainring or if you need to change up your gearing, knowing the chainring’s bolt circle diameter, or BCD, is key to finding the right ring for your crank's spider. The BCD is the diameter of the circle formed by the bolt holes. The CDG-2 quickly and easily measures the BCD accurately in millimeters for a wide variety of common four and five bolt chainring patterns. The CDG-2 also includes a center to center measuring scale and a quick reference chart for determining the BCD of less common chainring bolt patterns. For quickly identifying common 4 and 5-Hole BCD patterns, simply position the tips of the CDG-2 in the center of adjacent bolt holes and read the BCD in the appropriate window. For uncommon BCD patterns, position the tips of the CDG-2 in the center of the adjacent bolts and read the center-to-center measurement at the tip of the pointer. Locate the number of bolt holes on the chart and the closest C-C measurement determines the BCD. The CDG-2 is made of anodized aluminum and all markings are permanently laser etched for longevity.

    • Accurately measure chainring bolt circle diameters
    • Made of anodized aluminum for durability
    • Ensures you purchase the correct replacement chainring
    • Item #PAR003B

    Tech Specs

    Material
    aluminum
    Compatibility
    3-6 bolthole chainrings
    Recommended Use
    bike maintenance
    Manufacturer Warranty
    limited lifetime

    Tech Specs

    • Reviews
    • Q & A

    What do you think about this product?

    Have questions about this product?