What is the smallest suggested sprocket sizes to minimize the effects of chordal action?
The smallest sprocket is usually the driver or input sprocket. As the chain enters and exits, it rises and falls as each pitch engages and disengages the sprockets. This movement, called chordal action, causes chain-speed variations (drive roughness) that may be objectionable in some applications. These variations can normally be minimized by increasing the size of the sprockets.
