Chain Drive Question

[Adam Y.]

What type of units is L in? Where exactly do you measure the length of chain? Overall length or between pins or what? Or do you count the number of links?

Might as well borrow a bit more from my book.

These equations will provide physical lengths. To determine the correct chain length and center distance, use this procedure:
1)Estimate what the center distance (C) should be.
2)Chain lengths are based on an even number of pitches. To determine the number of pitches, divide the chain lenth by the pitch length. If the number of pitches of the chain is not an even number, round up or down for an even number.
3)Multiply this result by pitch length to get the final physical length of the chain.
4)Plug the pitch length into Equations 19 and 20 to calculate the center distance between sprokets.

The book was a whee bit vague as to what units L was in. Im guessing that it should be whatever untis the pitch is in. Metric for metric chain and the same for American chain.