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Proficient Motorcycling. David L. Hough
Читать онлайн.Название Proficient Motorcycling
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isbn 9781935484677
Автор произведения David L. Hough
Жанр Сделай Сам
Издательство Ingram
If you think it might help increase your conspicuity, here are some suggestions:
• Consider lighter-color riding gear such as a tan, silver, or bright blue. Add brightly colored vanity stripes to your darker-colored leathers, or wear a bright reflective vest over your jacket.
• Choose a helmet in a lighter, brighter color or a helmet design with bright stripes.
• When shopping for a new machine or repainting your faded bike, give priority to a bright paint scheme.
• Use amber running lights on the front, as widely spaced as practical.
• For nighttime rides, add reflective tape to the back end of your saddlebags, tour trunk, and helmet. Add multiple red taillights, preferably spaced wide apart.
CHAPTER 2
Motorcycle Dynamics
WHAT KEEPS IT BALANCED?
You can get down the road pretty well on your two-wheeler without having to know a lot of details. Once your bike is in motion, it’s relatively easy to keep it balanced in a more or less straight line. If the bike wanders a bit in the wrong direction, just lean it back toward your intended line. If you want to turn, all you have to do is lean the bike in the direction you want to go. Simple, huh? Well, maybe not so simple. There are a lot of riders around who demonstrate over and over that they are only half in control of their motorcycles.
Drifting Dan really wants his big tourer to make a nice crisp turn from a stop onto that narrow road, but as he nervously eases out the clutch, the bike seems to take command and swings wide over the centerline. Wandering Wanda wants her cruiser to just motor down the middle of the lane, but it sometimes creeps over toward the edge of the pavement, then back toward the centerline. Beemer Bob does fine at speed, but when he rolls into the parking lot for the breakfast meeting, his new sport tourer seems intent on wobbling over toward parked cars, and it’s a constant sweaty struggle to keep it between the lines.
One major reason Dan, Wanda, and Bob have difficulty getting their motorcycles to cooperate is that they don’t really understand how motorcycles balance and steer. Drifting Dan panics when his heavyweight touring bike swings wide, but when he attempts to muscle it back toward his lane, it just seems to go wider. Dan doesn’t realize he is actually steering the bars in the wrong direction. Wandering Wanda is paranoid about running wide, and she’s absolutely terrified of corners, but she is afraid to try that countersteering she’s heard about. Beemer Bob breaks out in a sweat when his shiny machine points itself toward car fenders, but he has yet to learn that it is primarily pushing on the grips that controls direction, not pressing his knees against the tank or pushing down on the foot pegs.
Dan, Wanda, and Bob have a common problem in their struggle to control their motorcycles. They all understand that you have to lean the bike to change direction. They just aren’t sure what really makes it happen. What they need to know is, to lean right, push on the right grip; to lean left, push on the left grip. If your machine tries to snuggle up to a parked car on your right, pushing on the left grip will lean it away from a fender-bender. It’s called countersteering because you momentarily steer the front wheel opposite (counter) to the way you want the motorcycle to lean.
Controlling your motorcycle in turns is more than just avoiding embarrassment. Crossing the centerline is an invitation to a collision.
It also helps to look where you want to go. If you don’t want to hit a pothole, focus on the road to one side or the other. If you don’t want to cross that centerline, look ahead down your lane; don’t gawk at the line. Even novice riders who haven’t mastered countersteering often gain considerable control by just getting their eyes up and looking where they want the bike to go.
Those are the two big secrets for the average situation: countersteer and look where you want to go. Now, go out and play.
Before you thumb the starter, though, let’s note that there are lots of hazardous situations out there that demand more skill than the average situation. For example, let’s say Beemer Bob zooms out of a tunnel in the mountains, smack into a 50-knot crosswind gusting from his right. The gust slams into the bike, pushing it toward the centerline. What should he do?
Bob needs to push hard on the upwind grip to lean the bike over and maintain enough muscle on the grip to hold the bike leaned over into the wind, but in a straight line. To counter that gust from the right, he needs to push aggressively on the right grip to lean the bike upwind. With the bike leaned over but not turning, steering isn’t going to feel normal, so Bob needs to apply pressure on the grips to make the motorcycle go where he wants it to go, and not just think “lean.”
Such situations remind us that balancing isn’t just a simple matter of nudging on the low grip. To prepare for a wide variety of situations, it might be helpful to look a little deeper into the dynamics of how two-wheelers balance and steer. If you get confused with any of this, I suggest you go out to the garage and try the experiments on your motorcycle.
And, as we get started on balancing dynamics, you should be aware that not everyone agrees about how it works any more than everyone agrees about love or war. From time to time, even the experts get into arm-waving arguments about small details, pens hastily scribbling diagrams on lunchroom napkins. What I’m going to offer here is the opinion of one aging moto-journalist/instructor, based on forty years of arm-waving discussions and napkin scribblings. And note that for what follows in this chapter, motorcycle means a two-wheeler, not a rigid sidecar rig or trike.
Two-Wheeler Stability
Occasionally, you’ll see a rider let go of the grips and lean back in the saddle at freeway speed. You may marvel at the naiveté of a rider willing to ignore such hazards as a groove in the pavement that might instantly yank the front end into a tank-slapper, but hands-off riding is a great demonstration of the unique stability of a motorcycle. The front-end geometry automatically stabilizes the bike in a straight line, self-correcting for minor changes in lean angle.
The simplistic suggestion is that this self-centering action is just a result of the castering effect of the front tire trailing behind the steering pivot axis, similar to the front wheels of a shopping cart at the grocery store. But two-wheelers are quite a bit more complex than shopping carts because they lean into turns. The self-balancing action of a motorcycle front end is a result of the combined effects of a number of details, including rake, trail, steering head rise and fall, mass shift, contact patch location, and tire profiles.
Rake/Trail
When test riders refer to heavy steering, they are talking about a machine that is so stable in a straight-ahead situation that it requires a lot of muscle to get it leaned over and held into a turn. What they mean by a flickable machine is one that is relatively unstable, that can be easily leaned over or straightened up with very little effort on the grips. This is a delicate balance, and sometimes the engineers have to walk a tightrope between low-effort (flickable) cornering and bad manners, such as the front wheel suddenly steering itself toward the curve (tucking), uncontrollable oscillations (speed wobbles), or falling into turns at slower speeds.
The behavior of a bike is related to its steering geometry. If you stand off to one side of your motorcycle and observe the angle of the front forks,