If you ask most motorcyclists how they negotiate a turn you will get a variety of answers. Some motorcyclists will answer they lean in to the turn. A few hardy souls will talk of hanging off the low side shifting weight to the inside of the corner. Some motorcyclists will say only with their attorney present. The physics of motivating a motorcycle around a corner are fairly complex. So complex are the physical skills some people manage to run out of corner fairly frequently.
Leaving out BMW’s paralever, Yamaha’s RADD front end, and the other specialized “new” ideas of front end geometry most motorcycles have a telescopic fork and, some type of damping system. All these factors affect the ability to negotiate a turn, or not. For the purposes of this article consider the standard motorcycle with numerous ponies, and a lot of ground clearance.
Entrance in to a corner usually starts with some type of braking effect. Engine braking and friction braking to be precise. The motorcycle as it slows will move forward compressing the front fork. This is known as weight shift. As the weight moves to the front wheel the available traction will increase significantly on that tire. The rear wheel however will lose a significant part of its traction. This weight shift is of interest to the motorcyclist because it explains why heavy braking in to the corner can end in crunched plastic and body parts. The motorcyclist wants to complete all braking and speed changes before entering the corner. Braking and accelerating lead to radical changes in the traction scenario. The goal is to ride as smooth as possible, creating a much more pleasurable ride. To keep the bike as smooth as possible it is a good idea to gently accelerate through the corner. Brake the motorcycle to the point that allows you to smoothly accelerate from entrance to exit. This will even the suspension out, keep radical changes in speed from occurring and impress your buddies.
Once the rider decides to begin the corner a complex set of actions occur. The first action should be a steady down and out pressure on the handlebar grip in the direction of the turn. This pressure will deflect the wheel in the opposite direction of the turn momentarily. This is known as counter-steering. Counter-steering is the only effective method of changing a two wheeled vehicles direction quickly. The wheel is deflected momentarily to the left ( for a right hand corner). The motorcycle will lean to the right and the wheel will quickly follow. The action is not a grab and twist, but a smooth gentle pressure in the direction of the turn. The motorcycle will continue to turn until the opposite pressure is applied.
The rider should maintain a posture of sitting forward, and looking all the way through a corner to the exit. The head and eyes should be level with the ground. Depending on the amount of lean riders may shift their weight to the inside of the corner. The reason for “hanging off” is to allow riders to keep the machine as upright as possible counter balancing the weight of the motorcycle. With the motorcycle as upright as possible it will maintain traction better and the rider can maintain control. Another added benefit to shifting weight to the inside is increased ground clearance. The motorcycle will be at less of an angle keeping side-stands and pipes off the ground. Large touring bikes and cruisers can benefit enormously from this technique. Why do motorcyclist look all the way through the corner? It has been said many times you go where you look. If you are sight seeing looking out at the peaceful pastures you may end up there. The rider who looks at the yellow line all the time two feet in front of his wheel will find corners a chore. It is easy to find these riders because they are the ones making constant small jittery movements during cornering. The riders who are always looking “down” at the fog line have their own distinctive signature. Fog line watchers during maximum or high speed cornering will appear to fall in to the corner than right themselves. Most of your racers will have broke most of the bad habits, and you will see them looking far up the track past the corner.
Smooth riders usually are looking five or more seconds ahead so that they don’t get surprised. On highway or wide open stretches their area of interest will be over twelve seconds ahead. In cornering they don’t get surprised, and they are always planning for the decreasing radius turn. The Motorcycle Safety Foundation has a real good idea on dealing with corners. Slow before the entrance of a corner to the speed that allows a constant acceleration through the exit, look all the way through a corner to the exit and beyond, lean in the direction of the corner, roll on the throttle and accelerate smoothly through the exit. Smooth riders last a lot longer and their insurance premiums are a lot cheaper. If you want to learn about riding smooth or just a little safer contact the Motorcycle Safety Foundation at 1-800-447-4700.