Positive Modes of Thinking About Speed
Many motorcycle crashes--and especially sportbike crashes--are caused by excessive speed. Yet some riders often see big numbers on the speedo and manage to stay out of trouble. So what's the difference between those who crash and those who get home safely? Is it just luck, or do the ones who stay healthy year after year know something about speed that the crashers don't?
Not to discount the value of luck, but riding fast
safely is an art that requires an understanding of speed developed through experience and supported by a sense of human fallibility. Those who ride fast but seldom crash have learned how to use the motorcycle's capabilities, but they have also learned about the limitations of the machine, themselves, and other motorists. These insights enable them to think about speed in ways that help them survive. Different riders think in different ways, of course, but here are three examples that illustrate how some riders approach the problems posed by speed on a motorcycle.
Braking Distance
A very basic problem that speed introduces is increased stopping distance. And not just a little. Stopping distance
quadruples when speed doubles. For example, assume that it takes one second to recognize a hazard, move your hand from the throttle to the brake, and begin to squeeze the lever. Assume too that you can brake well enough to meet a typical motorcop standard (not MotoGP braking, but easily good enough for a top MSF score). If you can do that, at 60mph you'll cover 250 feet before coming to a complete stop. But from 120mph you'll cover 820 feet--nearly three football fields for a full stop. And that's a best-case estimate. It gets worse on a dodgy surface or if you hesitate because you think that black cow in the road is really just an odd shadow cast by roadside shrubbery.
You can--and should--cultivate an understanding of braking distances by following Nick Ienatsch's advice in
Sport Riding Techniques: "If you ride at 100mph, practice stopping from 100mph." Or, to put it another way, if you
don't practice braking from 100, you shouldn't be riding 100. There is, of course, only one place to practice braking at that speed: the racetrack.
Cornering
Just as greater straight-line speed increases braking distance, greater cornering speed increases the demand for grip and lean angle. And again the relationship isn't a simple one: doubling turn speed quadruples the grip requirement. But that's not necessarily the most severe demand imposed by faster cornering. The limiting factor for getting a motorcycle around a bend may not be between the rubber and the road, but between the rider's ears.
To go faster around a turn, a rider must also speed up his thoughts and actions. Twice as fast = half the time available for thinking and control inputs. Consider a turn where, at 30mph, you have 3 seconds to locate a turn-in point, adjust entry speed, locate a steering target, make the steering input, and get back on the gas. At 60mph, the same actions must be completed in 1.5 seconds. What's more, greater precision is required at higher speed. At 30mph, straying 6 feet from your planned line or making a harsh throttle input may be errors the motorcycle can soak up. But the same mistake at 60 could put you into the weeds.
Faster cornering is a goal that many sport riders pursue. But those who get home safely think about cornering speed as a demand on both machine and rider. And they understand that latter is often the limiting factor.
The Tempo of Traffic
The pace of events in traffic is governed by roads, vehicles, and drivers. In an urban area dense with cross-streets and parking, traffic moves slowly because entering and exiting vehicles interfere with the main flow. A truck takes time to complete a left turn because it's big and accelerates slowly. And at a freeway merge, "friction" generated by drivers accommodating--or not accommodating--entering vehicles slows traffic down.
Failure of a motorcyclist to recognize speed limitations inherent in the traffic environment can result in crashes such as these:
- A motorcycle pops into the view of an oncoming motorist after the bike crests a hill. But the driver has already begun a left turn, and the motorcycle is going too fast to stop.
- The sightline between a motorcycle and an oncoming motorist is clear, but the bike is beyond the driver's "decision horizon"--the distance at which he considers vehicles to be a threat in this familiar location--and he begins his turn. However, the driver misjudged the motorcycle's speed, and because it was going twice as fast as normal traffic in this location, the two collide.
- On a freeway, a driver in the #2 lane sees a slower vehicle ahead and decides to move into the #1. Like most motorists, he glances in his mirror for no more than a second or two, and when he doesn't see anything, proceeds with his lane change. But he failed to see a motorcycle approaching in the #1 at 25mph faster than the flow of traffic. Because of its speed, the motorcycle was visible in the limited field covered by the car's mirror for only a short time, and the driver never saw it. The car cuts off the motorcycle, and it goes down.
A rider who wants to get home safely must consider the tempo of traffic. He may be able to make good time, but he is always in synchrony with the environment. When you're on their turf, you must adapt to survive.
These are a few possible alternatives to the pathological thinking about speed described in my first post. Rather than thinking in terms of speed limits, the speed the motorcycle is capable of attaining, or misperceptions propagated within the sportbike culture, look for limitations suggested by real-world experience. Of which we have seen far too many examples recently.
What modes of thinking have you found that help you recognize the danger that can accompany speed?
What modes help you recognize when speed is
not particularly dangerous and visiting the upper half of the speedo dial won't do any harm?
Has it been experience alone that taught you to make the distinction, or have there been instructors, peers, books, magazines, or forums that influenced you?