To put it simply:

A smaller gear paired with a bigger wheel will offer low torque and a higher top speed.

A larger gear paired with a smaller wheel will offer high torque and a lower top speed.

For our largest street wheel, the 107mm ABEC/Evolve, we recommend using the 38T drive gears as this offers the best torque.

For the larger all terrain tyres, the 175mm or 200mm, we do not recommend using the smaller 47T drive gears as it will put too much strain on the electrics due to reduced torque.

For a full explanation, check out the video below!