Originally Posted by khuon
It's semi-log in order to normalise the viewing so that one can determine appropriate overlap and shift points. the original poster is not interested in the actual numbers nor how they compare to other gear setups on other bicycles. The original poster was interested in figuring out the pattern of gearing progression on the Giant OCR2 and how it relates to which gear combination.
How does a sem-logarithmic graph "normalize the viewing"? The purpose of such plots is to linearize exponential relationships, generally for curve-fitting purposes, but everything here is linear. The overlap and shift points, whereever they are, will be on both linear and semi-logarithmic plots, just in different places. Does it have something to do with the angle of the chain between extreme positions of the chainrings and cogs?