Proficient Motorcycling. David L. Hough
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Название: Proficient Motorcycling

Автор: David L. Hough

Издательство: Ingram

Жанр: Сделай Сам

Серия:

isbn: 9781935484677

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       It is primarily tire traction that forces the bike to turn away from center.

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       Now leaned into the curve and turning, the bike is stabilized by gravity balanced against centrifugal force.

       Feedback

      Part of the confusion over motorcycle balancing and steering is that different machines handle differently and give different feedback to the rider. It’s not easy to differentiate between what the bike is doing and what the rider is doing. Ideally, if the rider maintains a slight press on the low grip, the bike will continue around a turn at the same lean angle. If the rider eases pressure on the grip, the motorcycle should roll itself upright and settle into a straight-ahead path. This would be called neutral steering, although it really isn’t neutral at all. And not all motorcycles have neutral steering.

      Consider a motorcycle with a tendency to fall into turns. With such a machine, you can initiate a right turn by pressing on the right grip; but once the bike starts to lean, it just wants to keep on rolling over farther and farther. So you need to counteract the motorcycle’s self-induced roll by maintaining a pull on the low grip to keep the bike from leaning over any farther than you need for the turn. It might seem that you are steering the front wheel toward the curve and that your steering input is what is causing the motorcycle to turn. What you are actually doing is limiting the bike’s own characteristic of falling into turns.

      So if you encounter a rider who is convinced he or she consistently steers the front wheel toward the turn, it’s most likely a matter of a bike that falls into corners. Generally, motorcycles that fall into turns are earlier designs with narrow front tire profiles and short steering trail.

       Center of Gravity

      When you hear someone attributing a motorcycle’s good or bad manners to the elevation of its center of gravity (CoG), remember that it’s mostly steering geometry that makes a machine feel sluggish to steer or top heavy in turns. Certainly, a cruiser that’s built low to the ground will have a lower CoG. But some CoG cruisers with a low CoG have heavy steering. And there are tall dual sportbikes with the engine mass up in the stratosphere but flickable manners. My point is that the actual height of the CoG is only a concern when you are balancing at a stop or pushing the bike out of the garage. In motion, front-end geometry has a lot more to do with how the bike balances. And if your favorite machine has some strange cornering feedback, be aware that you can do some fine-tuning by setting up the suspension and, if necessary, changing tire diameters and profiles.

       Body English

      Remember Drifting Dan, who can’t seem to control balance of his big road burner by throwing his weight around on the bike? It worked fine with Dan’s little 250 that he rode years ago, but it doesn’t work with his heavier touring bike. Sure, body English can cause a bike to change direction. But the result you get from throwing your weight around depends to a great extent on the relationship of your weight to the weight of the bike. The heavier the bike, the more its inertial and gyroscopic stability. For instance, slam your knee into the tank on a contemporary 250 lightweight, and the bike will head off in a new direction. Slam your knee against the tank of an 1800cc tourer, and the bike may wobble once or twice and then straighten right back up on its original path. With the heavier machine, Dan needs to focus more on countersteering and less on body English.

      The next time you are out riding, think about what you’re doing to control balance and direction. Are you sitting rock-solid in the saddle and just resting your boots on the pegs? Are you shifting your butt? Are you shifting weight from one foot peg to the other? In a turn, do you place more weight on the inside peg or the outside peg? Are you pushing on the grips or pulling on the grips? Are you pushing on the low grip or pulling? I’m not offering any correct answers here, just pointing out that part of becoming a proficient motorcyclist is figuring out what it takes to balance your machine and what it’s trying to tell you.

       Direct Steering Versus Countersteering

      A road racer pointed out to me an interesting phenomenon about steering input. While leaned over at speed on the racetrack, this rider observed that about half the time he was pushing on the low grip, steering the front wheel slightly away from the turn, and half the time he was pulling on the low grip, steering the front wheel toward the turn, all the while attempting to hold the bike on his desired racing line. He knew whether he was turning the front wheel toward the turn or away from the turn because he was hanging off the bike and could see the front wheel. He described pulling on the low grip as direct steering and pushing on the low grip as countersteering. The racer was struggling with the concepts of direct steering and counter-steering. Somehow he had come to believe that motorcycle steering had to be either direct steering or countersteering, but not both. His observation was that he was alternating between the two.

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       Countersteering is momentarily steering the contact patch opposite the direction you want the motorcycle to roll. Direct steering is pointing the front wheel toward the intended direction of travel.

      To help clear this up, let’s define direct steering as pointing the front wheel toward the intended direction of travel, in other words, steering the front wheel toward the left in a left turn. Was the racer direct steering? Yes, much of the time. But was he also countersteering? Yes, but only some of the time. We should understand countersteering to mean momentarily steering the contact patch opposite to the direction we want the bike to roll. Let’s be clear that countersteering isn’t a matter of whether the bars are turned left of center or right of center, or whether that takes a push or a pull, whether the bike is upright or leaned over, or whether speed is fast or slow. Whatever the position of the bike or front wheel, you momentarily steer the front wheel opposite the way you want the bike to roll.

      For example, if the motorcycle is leaned over in a tight left turn and then a crosswind pushes it over a little too far, momentarily pulling on the left grip will keep it from rolling over farther. Is that still countersteering, even though the front wheel is pointed to the left of center in a left turn? Sure. Countersteering is a momentary, dynamic input, not the direction the front wheel happens to be pointed toward at the moment. Or let’s say you are leaned over into a left turn and it’s time to lift the bike up and exit the corner. Momentarily steering the front wheel slightly more toward the curve (by pressing the grips more toward the right) forces the bike to roll more upright. The momentary press on the grip to roll the bike vertical is countersteering. You can’t determine countersteering from a still photograph because it’s a dynamic motion.

       Push Steering

      If you’re still a little confused about this countersteering business, I suggest a little experiment. The simplest way to describe countersteering is to push on the right grip to turn right or push on the left grip to turn left. Take your bike out for a spin; get up to 35 mph or so on a straight, vacant road; and consciously push lightly on the left grip. The bike will lean over slightly left and move over toward the left side of the lane. Now, push on the right grip. The bike will lean slightly right and steer back toward the right side of the lane.

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