Monday, April 5, 2010

RIDING SKILLS AND TECHNIQUES: Body Position and Steering

Whether you're going to hang off the bike on a racetrack or stay centered on it while riding on the street, proper body position starts at the footpegs and works up from there. Anytime you're not using your feet for shifting or applying the rear brake, place the ball of your foot on the footpeg. This allows you to shift your weight more effectively than hooking your heels on the pegs, as most street riders are prone to do. Proper body position starts with the ball of the foot on the footpegs and works up from there. Be consistent with where you sit on the seat while in cornering mode because moving even a few inches before or after ahs a big effect on weight distribution and handling; sliding up against the back of the tank is a good place to start. This also helps keep weight off your hands and wrists on the bars.

Get your body position set well before the corner entrance, as you begin your transition to the brakes, not, as most riders do instinctively, while you initiate your steering input. Ideally, the rider's upper and lower body hang equally off the inside of the motorcycle to shift the combined center of mass inward and allow the bike to remain more uptight for a given speed around a given radius corner. Riding with your heel hooked on the peg presents a couple of problems. First, most riders end up pointing their toes outward, where they can drag on the ground prematurely (very distracting, if not scary). And second, riding this way forces you to use your quadriceps (in your upper leg) to lift your butt off the seat for weight transfer. Placing the balls of your feet on the pegs allows you to also use your calf muscles and keeps your toes away from the asphalt. Next, sit on the front of the seat near the fuel tank to stay connected to the bike with your lower body and keep your weight biased toward the front tire. Be consistent with your seat position because it has a major effect on the weight distribution and, hence, the handling characteristics of the bike. Your back and arms should have a natural, relaxed bend to allow your body to absorb bumps without feeding them through to the chassis. You want your body to act like part of the bike's suspension, not part of the frame. Finally, as we described in the previous Riding Skills Series segment, grip the bars like you would hold a bird in your hand: tight enough to keep the bird from getting away, but not so tight as to crush it.

Stay Relaxed
It's important to remain relaxed on the bike. Remember that once a motorcycle is in motion, the gyroscopic effect of the wheels helps keep it stable and going in a straight line. The rake and trail of the steering geometry also assist in keeping the bike going straight, even after the front wheel is deflected by a bump or rock on the road, because of the self-centering aspect of the tire's contact patch positioned behind the steering axis. When a nervous rider clamps down hard on the bars, it feeds inputs that interfere with the bike's ability to straighten itself out. Stay relaxed and trust the bike. A slight arch in your back and a natural bend to your elbows helps you stay relaxed and absorb bumps without unintentionally feeding them to the chassis through the bars. Think of your body as part of the suspension, not part of the chassis. Use your back and abdominal muscles to help support your upper body weight and keep a light touch on the bars for improved feedback and stability.

Hanging Off
While there isn't a need for it on the street, hanging off the inside of the bike is a good idea at the track because it keeps the bike more upright for a given speed around a given corner radius. This then gives you two options: either benefit from more traction from the greater tire contact patch or increase your speed until you again reach your maximum lean angle. While you're beginning to set up for the corner, shift your body position by pivoting your lower body around the back of the tank to slide about half your butt off the seat. Doing this in advance of the corner keeps you from being rushed as you bend the bike into the turn and slows your perceived, or mental, speed. Getting your body in position and downshifting done well in advance of the corner gives you a significant amount of time to relax, set your entrance speed by smoothly releasing the brake and pick a precise turn-in point for the corner. Handling all the aforementioned tasks early frees up an enormous amount of time and concentration for the really important aspects of entering the corner.

Weight the inside footpeg and push against the tank with your outside thigh as you countersteer to turn the bike in. Applying multiple, subtle inputs to steer the bike helps you to stay light on the bars and keep the bike stable. As the bike leans into the corner, shift your upper body off about an equal amount to your lower body so that your back is more or less parallel to the centerline of the bike but offset to the inside about four to six inches.

Hold your outside thigh against the tank so that it supports most of your body weight and allows your arms to be relaxed at a natural bend. As you exit the corner, pull your body back up with your arms and legs combined; using only your arms can feed unnecessary inputs into the bars, causing the front tire to get light and initiate headshake while accelerating off the corner. Unweight your butt just enough to slide across the seat and back into position; don't jump up from one position to another, which can unsettle the bike. Consciously weight the outside footpeg to help the bike stand up and to transfer traction to the rear tire.

It's important to not hang off so drastically that it compromises your body's connection with the bike or your ability to control the bike should you lose traction from the front or rear tire. Keep your head upright, looking two to six seconds in front of the bike at all times. Most riders find it helpful to keep their heads close to perpendicular to the ground, which gives a better sense of balance and visual orientation, as well. If you stay tucked in behind the bubble, your vision of the road ahead will be compromised.

Steering Technique
There seems to be a constant debate about whether countersteering or lower-body steering is the most effective way to steer a motorcycle. The extremists who think it has to be one or the other are missing the point-using the upper and lower body together is by far the most effective and efficient way to steer a motorcycle. Your initial steering input should begin with countersteering (pushing forward on the inside bar to use the front wheel's gyroscopic effect to bank the bike into the corner) while at the same time pressing down on the inside footpeg. Isaac Newton discovered that for every action, there is an equal and opposite reaction. Pushing down on the inside footpeg at the same time you push forward on the inside bar helps effectively anchor the body to generate both forces and, as we shall see, the forces complement one another in steering the bike. Once countersteering banks a motorcycle into the turn, increasing lean angle is a matter of pivoting the bike around its center of mass. The greater the lean angle, the tighter the bike carves through the turn. Footpegs are effective levers on either side of and slightly below the center of mass. Pressing down on the inside footpeg helps pivot the bike around its center of mass and steers it into the corner while requiring less effort from your upper body at the bars.


Notice the progression of how these riders shift their weight from right to left while transitioning from one direction to the other. By weighting the inside footpeg and using the outer thigh to pivot the bike around its center of mass, substantially less countersteering force is required. Applying the inputs as low as possible allows the bike to remain more stable than using countersteering alone. Throughout Kevin Schwantz's career on Grand Prix bikes, which weighed between 250-286 pounds and produced upward of 175 horsepower, he found that the lower his steering inputs were into the chassis, the more stable the bike was. Consequently, while he did use countersteering to initiate the corner, from that point on he used as little upper body input as he could. Instead, he relied on weighting the inside footpeg and using his outside thigh to pull the fuel tank to the inside of the turn and finish the steering input. As a result, his arms could stay more relaxed on the bars and keep the bike more stable. Schwantz's motorcycle competition career began at a young age in observed trials, where he learned the value, even necessity, of using lower body inputs to control his motorcycle. This lesson he applied all the way through his World Championship-winning career.

While pushing forward on the inside bar, weighting the inside footpeg and pulling the outside thigh toward the inside of the corner might sound complex, in actual practice you'll likely find that you've already been doing it to some degree. When focusing on using the upper and lower body to steer the bike more effectively, most riders feel that someone's installed power steering on their bike. It turns in much easier with less effort, and with a little practice it becomes second nature. The added stability of this light-on-the-bars technique is ever more important as bikes get lighter, shorter and more powerful. From the apex of the corner on, weighting the outside footpeg gives a couple of advantages. First, it helps stand the bike up off the edge of the tire to generate a larger contact patch and allow the rider to accelerate. Second, it helps transfer the rider's weight through the rear contact patch to the ground, increasing traction.

This is another lesson Schwantz learned from a trials-riding mentor. Traversing a steep slope of loose dirt on a trials bike while weighting the inside footpeg forces the rear contact patch away from the hillside and causes the rear tire to lose traction and slide downhill. Riding across the same slope while weighting the outside footpeg forces the rear contact patch into the hillside, maintains traction and allows the bike to ride straight across the hillside. Whether you're riding across an incline or leaning a motorcycle over on the pavement, the principle is the same. Practice using your upper and lower body together, and you'll find that your motorcycle steers more easily with less effort and remains more stable.

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