Part 173 - Riding Skills Series The Throttle-To-Brake Transition... (",)

Riding Skills Series The Throttle-To-Brake Transition

By Andrew Trevitt

Photography by Brian J. Nelson

One often-overlooked skill that can pay big dividends on both street and track is the transition from throttle to brakes. The time it takes to release the throttle, pull the brake lever and reach maximum braking force may seem short and insignificant, but translating time to distance shows that it plays a much greater role. At the track it can make the difference between outbraking your opponent or not. On the street it can mean stopping in time to miss the car that pulled out in front of you. Or not.

If you use more than two fingers on the front brake, make an effort to learn how to use just two or even one. This not only gives you more steering control under braking, but also it makes reaching for the lever that much easier and quicker. Covering the front brake with two fingers on the street will reduce your reaction time.

Making the physical transition from full throttle to full braking requires dexterity and proper lever placement. Good-fitting gloves will free up your fingers without being loose enough to catch on the lever, and the brake lever should be low enough that you aren't forcing your fingers up to reach it.

Consider the data traces that show the throttle-to-braking transition for two riders at the end of the long back straight at Spring Mountain Motorsports Ranch in Pahrump, NV. Figure 1, for the first rider, shows that at around the 92.5-second mark, he gradually lets off the throttle (red trace). The brake lever (green traces) is pulled at about 93.7 seconds, more than a second later. It's not until 94.1 seconds that maximum braking force is reached, as evidenced by the yellow G-force trace reaching a minimum value.

Figure two shows a second rider at the same transition, with correspondingly shorter times between the important marks. The throttle is closed much more abruptly, the brake lever is pulled slightly sooner, and the G-force trace has a steeper slope to maximum braking. In all, the transition from full throttle to maximum braking for the second rider is less than a second, compared with 1.6 seconds for the first rider.

Figure 2 The same zone for a second rider shows a quicker release of the throttle and correspondingly sooner application of the brake. From there, G forces drop quicker, indicating a faster transition to full braking. The savings overall is more than a half-second, or about 95 feet at 130 mph in this case.

Figure 1 This data shows the braking zone at the end of Pahrump's back straight. Note where the rider releases the throttle (red trace), applies the brake (green) and reaches maximum braking force, which occurs at minimum G force as shown by the yellow trace.

Over the course of the last two years, we've gathered data for numerous riders, and traces resembling those for our first rider here are far more common than those for the second. And when you consider that the first rider is an expert-level club racer, it's a safe bet that the average rider's times would be even significantly longer.

Let's look at some numbers: While the above example is a fairly extreme racetrack scenario, say you could improve your throttle-to-brake transition by a mere .25 seconds-an attainable goal for many riders with practice. At just 60mph, that correlates to 22 feet. You can outbrake a lot of people at the racetrack if you had 22 feet to spare. In our example above the speeds are much higher, approaching 130 mph, and the corresponding distances even greater. On the street, 22 feet is the width of a typical intersection and that quarter-second has a potentially huge impact on accident avoidance.

How can we improve the time it takes to make the throttle-to-brake transition? The first part-releasing the throttle-may seem simple but is potentially the most difficult. On the street it comes down to reaction time, how quickly you can make the decision on how to best avoid a problem, and how confident you are to execute that decision. Keep your eyes up and scanning ahead so that you can spot potential dangers as soon as they arise. At the track, reference points are key. It helps here to have a reference point up to which you can hold the throttle open until, rather than a marker at which you pull the brake lever. This will force you to speed up the throttle-off transition as it becomes part of your braking zone, and not let you cheat by closing the throttle and coasting up to your brake marker.

As our rider approaches his brake marker, note that his fingers are already moving toward the brake lever while he is still accelerating. Once the throttle is shut, the brakes are applied as quickly as possible. The limiting factor from that point is weight transfer: If you grab too much brake at once, the front wheel will lock up as there is very little weight on it. It will take practice to find the relationship between weight transfer and how quickly you can apply the brake, but this skill will serve you well both at the track and on the street.

Releasing the throttle and reaching for the brake lever also requires dexterity. Using two fingers for the brake, or even one, will help here, as will keeping the front brake covered on the street. Good-fitting gloves and correctly positioned levers can make the reach to the lever easier, and practicing the movement will reduce the concentration required.

Once the brake is applied, reaching maximum braking force is the next step. If you apply the brakes leisurely, time is lost as you are not using their full potential. Apply the binders too quickly, however, and you run the risk of having too much braking force on the front tire before the weight of the bike has transferred to the front wheel-leading to a locked front wheel and resulting tipover. Gradually but firmly apply the brakes in proportion to how much weight is transferred.

As always, practice is imperative and this is one skill that directly transfers from the track to the street. If you learn at the track how quickly you can reach maximum braking force without overcoming the available traction, it will become second nature to you. Then, the action is automatic when it comes time to do the same on the street and you can significantly reduce the danger of locking up your front wheel in a panic stop.

Perfecting the entire transition from full throttle to full brakes is best practiced at the track, but the skill pays big dividends both at that venue and in everyday street riding. And it's something worth practicing; that 22 feet could come in handy some day.

For more riding tips, visit www.sportrider.com/ride

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