The phrase refers to a tool, often a website or a formula, designed to determine the appropriate number of links for a bicycle chain when used with a Shimano drivetrain. It takes into account factors such as the number of teeth on the front chainrings and rear cassette, as well as the wheelbase or chainstay length of the bicycle frame. Failure to determine the correct length can lead to poor shifting performance and potential damage to components.
Accurate chain sizing is critical for optimal performance and longevity of a bicycle’s drivetrain. A chain that is too short can overstress the rear derailleur, potentially causing damage and hindering shifting. A chain that is too long, on the other hand, may result in excessive chain slack, increasing the risk of chain slap and poor shifting precision. The practice of ensuring correct chain length has evolved as drivetrain technology has advanced, reflecting the increased number of gears and tighter tolerances of modern bicycle drivetrains.
