There's a lot more then just slowing down for the beginning of a berm (rutted) corner. You have to continue to control your speed all the way through the berm. Once your front wheel checks into the berm it's all done with the front brake and throttle. This YT video will give you a little better understanding.
If you really want to improve your motocross skills through the berms get my VO3 DVD #5 (Motocross Berm Corner Techniques DVD or Stream). You'll be surprised how much easier and faster your bermed corners will be when you know all the secrets of how to practice them.
If you like my Blog tips be sure to follow this blog. How do you do this? In the upper right-hand corner, click the "Follow this Blog" button.
Professional MX Trainer