Originally Posted by
dedhed
The spacing changed just about every change. What didn't change was the actuation rate of the RD. The shifters pull different amounts of cable to have the RD match the cog spacing so what happens is RD works from 6-10 road but the shifters and cog count have to match.
Thanks. Of all the explanations in this thread of the evolution in spacing over the years, this is the one that clicked for me. Thank you!