The calibration figure is the simply number of pulses to give a certain indication. Logic would suggest if you wish your speedo to read say 3% less, the you would need to INCREASE the original calibration factor by 3%? Anybody tried that?

Doug
2011 Plus 4 in Rich Maroon

1972 750 “ComDom” sprinter
1958 Triton 650
1992 Triumph Trophy 900