For motorcycle enthusiasts it is important to understand motorcycle safety and to know the best techniques to get the most out of your bikes brakes in emergency situations. Here is an illustration to explain the physics of traction of a motorcycle tire on the road in a braking situation. Not the entire bike, just the tire standing upright.
If we try to pull it across the road with no weight on the tire it slides pretty easily. Now let’s add some weight to the top of the tire and try to slide it across asphalt. It takes a lot more energy to slide the tire with weight on it. In other words, the tire has a lot more friction, traction or grip on the road when there is weight on it. If you add more weight, you get more traction.
A motorcycle has a certain weight distribution designed by its manufacturer. Let’s assume that a bike has 75% of the weight on the back tire and 25% on the front tire. Assume the bike is rolling along and the brakes are applied.
Notice that the front shocks begin to contract as the weight of the bike shifts forward putting more pressure on the front tire. And in keeping with our earlier discovery of the relationship between weight and traction, the traction on the front tire of the bike increases and the rear tire traction decreases.
So the result of the weight shifting to the front tire is that the rider can now apply even more front brake power due to the shifting weight on that tire than he could a moment before. And as the rider uses more front brake, then more weight shifts forward, increasing the traction for the front tire, which enables more of the front brake to be used.
This is why the front brake is so much more powerful than the rear brake on motorcycles. This is why most bikes have two large brake disks on the front wheel and a single small disk on the rear. It’s simply using the laws of inertia and weight shift to stop your bike. When you want to get the best motorcycle parts like rear brakes, you can get them for an affordable price via motorcycle importers.