Chain Length Calculation
From Pvdwiki
Contents
Understanding the Problem
A chainwheel is not round. Rather, it is a polygon with facet lenth of the chain pitch. The chain leaves the chainwheel, on average, tangent to the pitch diameter. The chain then travels in a (theoretically) straight line to the other chainwheel, meeting it in a similar fashion.
This makes for some interesting math.
The most accurate math
Another formula:
File:Emerson-ept-math.gif
Some Approximations
I'm not a big fan of approximations. Spreadsheets exist for a reason.
I will add some though, just for comparison.