I am using KBS48121L.
The diffrence is not enough to explain in words
![Grin ;D](https://goldenmotor.com/SMF/Smileys/default/grin.gif)
You have to feel it!
Max speed for my bike is 40 km/h.
I am using MTB 2,35 inch tire, so less top speed.
But I don't care 40 km/h is enough for me
![Grin ;D](https://goldenmotor.com/SMF/Smileys/default/grin.gif)
Crazy torque
![Shocked :o](https://goldenmotor.com/SMF/Smileys/default/shocked.gif)
but aware with weak bike build you can destroy your motor and bike
![Shocked :o](https://goldenmotor.com/SMF/Smileys/default/shocked.gif)
Yes I have used the internal controller for one test ride.
I don't like it!