I never use front break unless the rear brake is already engaged. Reason I hit a rock doing 35 mph and the front tire went flat in two revolutions. If i had conditioned myself to use the front brake it would have been disaster. I grabbed all the rear brake i could and stopped . . . I went over the handle bars ,in a strip mine, on my motorcycle because i grabbed the front brake. Not fun when your bike is chasing you down a high wall (overburden pile of dirt) . . . If it is wet or slippery and you use the front brake , without the rear chances are you will fall, The rear wheel can slip and slide all over the place. Just watch fixed gear riders. If the front wheel slides it is game over