Reaction Time | Don’t Blink | Code Break

By Keith Code, Photography by Gold & Goose

The moment it takes to observe and respond to something while riding seems as though it happens in the blink of an eye: 0.3 to 0.4 of a second. Blinks are natural and necessary, of course, but they take time, and time equals distance traveled. At 60 mph, that blink covers around 35 feet, about two car lengths or five bike lengths of road. Add in your reaction time and it’s another 21 feet or three bike lengths. In the blink of an eye you can miss an opportunity to correct an error.

When thinking about time, it’s also necessary to consider the nature of rider input. It breaks down into three basic forms: predictive, reactive, and predictive-reactive.

A predictive input is any planned control input that has a desired and defined result. This would be a rider’s Plan A. Simple, two-part actions can be performed in 0.1 to 0.2 seconds when planned. The opposite is reactive input, which is any control action triggered by an external situation. Here, the rider is forced to respond outside of his planned actions. Typically this takes .25 seconds or more. If reacting predictively is the best case, operating reactively is the worst case.

In between these are what we call predictive-reactive inputs, which are planned responses to unplanned situations. Think of these as anticipated damage control, your emergency Plan B. Like wearing a helmet, they are there when you need them.

Smart riders learn and are prepared to use predictive-reactive reactions at any time. For example, predictive-reactive inputs with the throttle include adding gas to save a front slide; staying on the gas for momentary rear wheel slides rather than chopping the throttle; and rolling off, not abruptly closing the throttle, in reaction to a big rear slide.

Predictive-reactive planning applies to braking as well. Examples include easing out of the brake (either one) the instant that wheel locks up to regain control; lightly coming into the front brake while simultaneously bringing the bike up for an in-corner emergency; and trailing off the brake pressure as you lean in when entry speed is too high. Another example is using both brakes lightly in a run-off-the-road situation rather than hammering one or the other. An important Plan B reaction is using the front brake to ensure a low-side rather than a high-side when a crash is imminent.

Think about how predictive-reactive movements apply to body position. A few examples include relaxing rather than stiffening up in a crash, which can help avoid broken bones; relaxing on the bars when they weave or shake; staying in the seat in “panic braking” situations, helping to prevent an endo; and putting as much heavy braking force into the tank with your knees rather than into the bars through the arms, where it tends to induce a front slide.

Predictive-reactive instincts should inform your steering inputs—as in bringing the bike up to vertical the moment before leaving a paved road surface to help avoid a slide; saving a very low-speed tip-over by turning the front wheel into the direction the bike is falling rather than the reaction to turn the wheel away from it; and definite counter-steering employed in any rapid swerve maneuver.

To put these Plan B inputs in perspective, the 0.3 to 0.4 seconds is, literally, the defining amount of time to save it if at all possible. Picture running wide in a corner. At 30 mph you are traveling 44 feet per second, in a 10-foot wide lane. A 0.4 second blink is 17.5 feet; more than enough to catalyze a panic-induced error. Well-trained riders also know that’s enough time to switch to Plan B, the predictive-reactive maneuver, to save the situation.

By Keith Code
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