Motorcycles offer the potential to experience acceleration that's impossible to perform in a car — but you have to know how to stop. Sean Smith at Hell For Leather explains the complications. — Ed.
Braking seems pretty simple on the surface: squeeze the lever and the bike slows down. You might have heard the old adage, "Fast riders have slow hands." If you take an MSF course, they'll tell you not to grab the brake lever and instead squeeze it slowly, but they never really offer an explanation. I don't know about you, but I've always had a hard time doing just what I'm told without being told why. Maybe you keep crashing your bike because no one has taken the time to explain exactly why a gentle approach with the brake lever is a good plan. Or maybe you're an experienced rider who has figured out braking intuitively, but would like to know more about the nuts and bolts. Understanding what squeezing the lever does, how braking is affected by your suspension, and how to be smart about braking by being aware of your surroundings will make you a more skilled rider who can avoid accidents.
On a modern motorcycle squeezing the front brake lever pushes a hydraulic piston into a cylinder which forces fluid out and through a tube that's connected to a caliper. In terms of mechanical activity, it's a pretty simple process. There's no computers involved; the caliper's pistons are forced outward by the pressure of the fluid and they squish brake pads into a rotor that's connected to the front wheel. So, squeeze the lever, and the force you apply is proportional to the force applied to the front wheel.
Just because the wheel stops, doesn't mean you and the bike stop too
Did you catch that part? Squeeze the lever, and the force you apply is proportional to the force applied to the front wheel. Grab the lever hard and fast, and what is going to happen? Immediate force squeezes the brake pads into the disk that's attached to your front wheel. Endowed only with its usual amount of grip, the front wheel stops.
Unfortunately, just because the wheel stops, doesn't mean you and the bike stop too. You and your bike have a lot of momentum and something trivial like a stopped front wheel dragging some rubber on the ground is not going to get in the way of physics. Squeeze the lever over a longer period of time (we're talking milliseconds here) and your suspension will help you stop without crashing.
Now is also a good time to mention maintenance. If you can't remember the last time your brake fluid was changed, then you're almost certainly overdue. If you have a bike with rubber brake lines and it's more than three years old, you need new brake lines. Pony up the extra bucks for stainless braided lines - they're dirt cheap on eBay and the added feel and performance make them more than worth it. Riding with spongy brakes that only sorta work is a recipe for disaster.
The front of the motorcycle is supported by springs which are in turn damped by hydraulics. If you didn't have springs, it'd be like riding your fixie - and there's nothing wrong with that as long as you're staying under 25mph. The added hydraulics keep your bike from riding like a pogo stick. The whole suspension package is usually hidden away inside forks, but weirder people have built bikes that use a shock and some sort of linkage. So what's this have to do with braking? Well, it turns out that braking and suspension are pretty much married and what happens to one has a significant effect on how the other works.
Riding a motorcycle at its limit is incredibly hard.
Say you're riding at 40mph and you need to slow to a stop. Use the lever and the brakes do their hydraulic thing to squeeze the rotor and slow the wheel. As you're decelerating it causes more weight than usual to be supported by the front wheel. As weight is transferred to the front, the suspension compresses and the tire flattens out, which in turn, gives you more tire contact area, allowing for more grip and, thus, more braking. Weight will only transfer once you've started braking and suspension can only compress so fast. If you apply a lot of pressure very fast (like you might if you realized that you were about to hit a CB400 directly in front of you) the weight of the motorcycle doesn't have time to transfer, squish the tire and compress the suspension. Squeezing the lever slowly will build braking force more gradually. That's not to say that it takes a lot time or even significantly longer than if you just grabbed the thing, but the difference of a few parts of a second is all it takes.
It helps to know when you should brake and where you want to stop. That's right, you should look where you're going. Look as far ahead as possible while still being able to keep tabs on what's going on directly in front of and next to you. Looking at a bumper that's eight feet in front of you in traffic will set you up for disaster (just ask the MSF instructor I watched plow into the back of a suburban on a brand new Multistrada S Touring last Saturday). If you know what's coming, you won't get caught out. It's as simple as using your eyes. But looking extremely far ahead is no good either; you can easily end up missing a tire swallowing pothole or a minivan trying to change lanes into you.
In the long run, using the brakes is really a lot less about the technical skill needed to operate the lever and more about using your eyes and consciously picking where you want to go, when you want to slow down and when you'd like to stop. If you can do that then you'll probably never have a problem with grabbing at the lever and locking the front wheel.
Now, I've been told that there is another brake on motorcycles that you operate with your right foot. If you're riding a sport or sporty standard bike and you need to stop in a hurry, the back brake is basically useless. Trying to stop in a hurry on a bike like this will put 99 percent or more weight onto the front wheel and almost any application of the rear brake will lock the tire. It won't make you crash, but it will zap valuable attention. You won't really stop any faster and having the rear tire moving instead will help keep the bike more stable.
Now, that rear brake business only applies to sports bikes and the like. If you're on something a little more laid back, with a longer wheelbase and lower center of gravity, then the rear brake will help you stop significantly faster. If you've got a passenger it's the same deal. Your center of gravity will be moved much further back than usual and in addition to effortless wheelies, the rear brake becomes an important tool in slowing the bike.
Riding a motorcycle at its limit is incredibly hard. To safely control a motorcycle that is constantly at the limit of traction you need both considerable skill and intense focus. It takes serious commitment to get it right, to perfect your body position, lines, timing, throttle control and braking takes years and nobody ever really gets it 100 percent right every time. Knowing how to stop in a hurry is a good thing to have in your back pocket, especially if you live in one of the 49 states that don't allow lane splitting.
To recap the lesson: don't grab the front brake lever, slowly squeeze it, working up to the amount of braking pressure you need to stop. You'll feel the suspension compress and the tire gain more grip as you do. You need that added grip to stop safely and quickly. You can practice in an empty parking lot. Being able to employ your motorcycle's full braking ability is an essential riding skill. Work at it until you can consistently apply full braking pressure without having to think about it.
This story originally appeared on Hell For Leather on May 13, 2011, and was republished with permission.
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