I just finished a test ride, after installing the new military precision resistors (for the gear position sensor voltage divider).
The reading are super accurate, and even though I did not ride much, and the temperature did not change too much, gear reading are rock solid!
NO FI codes
I used 2 X 499K Ohm resistors (CMF55499K00BEEB),
I also installed the DS18B20 temperature sensor in the front box (where the LCD is), so now I have two temperature readings: One which is true ambient air temperature, and another which is the Arduino's on board temperature. I like it.
I got two more military spec resistors for the battery voltage divider but am too lazy to install them, since I need to remove the existing resistors - a lot of clean up work.. next week.
@Voltar: If you decide in the future to have voltage dividers, e.g. for measuring the battery level, please remember my advice/lesson - For ADC ALWAYS
use high precision, low PPM/K metal film resistors..
Thanks everybody for helping out!!
I will do more test rides in warmer days, and hopefully can keep reporting a stable solution.