If, by “stock axle” you mean the Bit Char-G axle, thenyou use the black pinion…
this is the bottom line:
2.2 motor is the same whether it says BIT RACER or BIT CHAR-G.
STOCK Bit Char-G axel = black pinion.
MODIFIED Bit Racer axel = white pinion. ONLY IF YOU ARE USING A BIT RACER AXEL TAKEN FROM A BIT RACER.
