A little test for those who believe that a rear brake has a greater stopping power than a front brake
Ride along at a set pace, at a given point pull one brake hard until you stop
Repeat the process using just the other brake
I'll bet a whole cake, yup I'm risking cake on this, that you will stop quicker just using the front brake compared to just using the rear brake braking from the same speed & from the same point
The reason for shifting your weight back under heavy braking is to stop you going over the bars.
180 up front 160 out back.