My bike is just a one tooth less on the front from the std. issue sprocket.
Result.
The -12.5 SH setting from the on-line calculator (actually 14.4% wrong in actual speedo terms) which some others on this site believed to be 'wrong' is actually just incredibly accurate. I mean it is exact to within a half mile an hour at 100. Perfect at 30. Not oh-just-a-bit-faster-through-the-speed-camera-as-speedo-error etc. It is EXACTLY CORRECT.

I am amazed how it does that reset that well. Very good bit of kit
One down side is I now have to redo the digital gear indicator setting as I can't get a six speed reading as it works on pulses off the engine related to speed etc. With the correct speedo changes it has upset it a bit. Says I've only got a five speed 'box. ha ha Small price to pay!!!!!!!!!!!!
I also like the remote top speed recall at the touch of the button. Kinda fun.
Reset the digital gear indicator too now so all OK and six gears are 'back'.