Yeah, actually they eat up some material from the shaft to reduce its size from 4mm to 1/8". And if you give the Mamba Max motor a look, you'll find that it actually has a 4mm shaft with a reduced size after it comes out of the bearing.

Also, you can actually ask Mike to bring you a version of the motor with this shaft diameter.

What turn are you gonna take? 6T or probably 8T?

Gonna try 6t.

So you'll be near 38000rpms and that is quite similar to a 11T motor. Start from 19t pinion and I'm sure you'll hit the sweet spot with a 21-22t pinion.

This motor should be crazy! Hope she runs cool without heatsink (limited space for a heatsink in b4.)

The 1930 pushed a emaxx around with out alot of heat issues. I sure it should push a b4 no prob.