Let me try to explain how I understand this difference in tread pattern front to rear. I learned this very quickly from my mountain bike tires. (don't ask) It's actually very simple and makes perfect sense when you think of it. The tread is designed to provide maximum contact and grip. Front tires and rear tires require grip, for the most part, in completely opposite ways. Rear tires need maximum grip to propel the bike forward, or accelerate. Twist the throttle and it's the rear tire that is using contact to go forward Front tires need most of their grip for braking or decelerating. Pull in that skinny right hand lever and the tire grip is applied to the road surface in completely the opposite way as the rear tire. So now how does that not make perfect sense?