Kind of depends on where you ride and how you are geared. Also how heavy you are and how brave/stupid. If it is flat I can stop just about as fast without the front brake as with. I can lock the back wheel up when stopping so the power is there but it is a little hard to modulate. It is a mixture of the wheel turning and then locking up for a second and then turning again, skipping. If I am slowing down a hill, in order to stop, I have to use my brake. I only run the front brake, but I have both levers on the bike to have a hand rest and I have thought about using a tandem splitter so I can brake with either hand.