There are two obstacles you will always have to face on the track: ruts and corners. Combine the two and traversing themcan be frustrating. The power and torque that modern four strokes produce is pretty incredible and lines get dug out quickly. Corners are the backbone of speed which makes it essential to be extremely proficient in riding at any situation.
One thing that has always helped me is to concentrate on one corner that is giving me problems. Try to get to the track later in the day when it is rougher and not as many people are there. Find your corner and enter the track safely in the section before, then hit the corner and go back to the previous section to repeat. If there aren’t many people, this will allow you plenty of time to find what you need to work on.
The first aspect you need to look at is your entrance technique. You want to be in the attack position all the way through the chop. Braking should be gradual; do not lock the back tire up or the rear end can sway side to side. For inside ruts, putting more emphasis on the front brake will get your front forks to squat lower so you can carve harder. As for outside lines, it is better to use the back to keep more momentum up.
When it comes time to sit, the process from standing to sitting should be one, fluid motion. You sit, put the inside leg up, and apply the throttle smoothly. Some have a tendency to blip the throttle and it bounces them around. The suspension throws the rider from the flow of the turn as leaning and steering become out of sync. A simple way to help with this is to just look ahead! When you approach the corner, look at the apex. As you get closer to the apex, begin looking further and further ahead to the next obstacle. You go wherever you look.
One overlooked method is to stay relaxed. Ride with the turn and don’t try to blast through it. Don’t tighten up so much and worry about messing up. You know how to ride a bike so have confidence in your abilities. Take some time to get this down and you will be making up time on every one.
Source: http://www.mxtrainingblog.com/riding-techniques/rutted-corners/
Frederic Bolley Brian Myerscough Thomas Allier Broc Hepler