Jsharp,how do you know the speedo was off before you changed the c.s.?...did you use a GPS to find the accurate speed of bike??
Checked it with mile markers and then with my GPS. Over 6% error to the high side. 60MPH indicated was more like 56MPH actual. It's now dead on after going to the 16T front which was just over a 6% gearing change.