Ninja 250 front brakes vibrating whole bike when I stop?

When I just apply the normal braking force it shakes pretty bad. What's wrong with it? The disk?

Ive had the same problem and was told it could have been one of many things. One, your brake discs arent on correctly (like one side has more pressure than the other side. That was my problem. Another problem was that the rotor could be screwed, unequally warn, which is causing the disc to slip, and if thats the case, chances are its not equally warn on each side, causing each pad to get grip at different sections, thus causing vibration, and shaking.

warped diskStuck caliper putting more pressure on one side.Bike could be dangerous as the vibration is really just micro stops in the wheel spinnng, at some point, unaddressed, the wheel locks up instead of vibrating.This results in a condition known as end over. that is when the back end goes over the front as when doing a stoppie, only, it just keeps going.Road rashes and broken bones usually result as a by product of this condition.