Originally Posted by Zouf
I believe you need a course in physics.
First: Max brake force from (any) wheel is limited by slip between the tire and the ground. Slip is reached when the braking force is equal to the slip limit, itself directly proportional to the vertical load on the tire. More load = higher slip limit = higher brake force..
Got it.
Originally Posted by Zouf
Second: brake force, regardless from which wheel it's generated, will cause a pitching moment, and thus will load the front wheel, and unload the rear wheel. Total wheel load (front + rear) will remain equal to the total mass (bike + rider), but the front will load - you have a brake force acting horizontally below the center of gravity, there has to be a reaction somewhere..
No problem with that.
Originally Posted by Zouf
Third: Combine #1 with #2, and you get: as the braking force increases, the front wheel loads, and its max brake force increases; at the same time, the rear wheel unloads, and its max brake force decreases..
That makes sense.
Originally Posted by Zouf
All the stuff above is not something like an opinion; it's hard solid physics. And you see the resultant of all this in the size of brake discs on cars (often larger in front than in rear), brake discs on motorcycle (dual, larger rotors in front), etc.
True, rear brake will not make you go over the bars, and front brake can. But rear brake max stopping power is limited, and the result once you reach it is a loss of rear wheel traction - not great in a turn, as the skin on my right knee can attest. So yes, the front brake should be used a whole lot more than the rear brake, if you really want to stop that bike as quickly as possible.
I have no argument with what you have said. I understand all of that.
Perhaps some engineering or physics student can produce an equation to answer this. If I use both brakes, will the rear wheel unweight the same amount as it would if I use only the front brake?