No matter how much a person loves to fly through the wind on a motorcycle, sooner or later your bike has to stop. That's why your bike has brakes, and the most efficient type of brakes are disc brakes. To understand how disc brakes work, think about the brakes on a ten-speed bicycle. When the brake lever is squeezed, a cable activates a set of calipers with rubber pads to clamp down on the rim of the wheel. This friction transfers the bike's kinetic energy, or momentum, to heat, and the bike slows to a stop. Disc brakes work similarly, but instead utilize hydraulic pressure inside a caliper that forces a set of friction pads against a metal disc (sometimes called a rotor) that is attached to the hub.

Without proper maintenance to your brakes, you could be losing 10, 20, or even 30 percent or more of your bike's braking efficiency. Those percentages may not seem high, but think about it this way. If you could improve your bike's braking by even 10 percent, it would mean you are reducing your emergency stopping distance from 100 feet to 90 feet. This could keep you out of a nasty accident.

The first step in disc brake maintenance is identifying what kind of disc brake system is on your bike. Some discs and calipers are fixed, which means they're hard-bolted to the wheel and forks and have no capacity for movement. These braking systems depend on the alignment of the front wheel to maintain efficiency. Any front-end misalignment can cause brake drag, squeal, overheating, discoloration, and excessive pad wear. So, if you have fixed discs or calipers, or both, keep a close eye on your bike's alignment and have it checked regularly by a pro.

Other disc brake systems use floating discs and calipers. A floating disc is attached to the hub using spring-loaded fasteners that allow the disc to maintain correct alignment with the brake pads through the flex of the bike's suspension during stopping. It's your job to make sure that the floating discs aren't loose or that they don't rattle. Now, what about ABS? Those initials stand for Anti-Lock Braking System. That's basically what happens when you turn the actuation of disc brakes over to a microprocessor. By using a computer-controlled pulse of hydraulic fluid, ABS prevents the wheels of your bike from "locking up" on slick or icy pavement.

Once the type of system is determined, it's time for a thorough check of your brakes. First, look at the disc. You can find trouble on the disc by looking for "grooving" or marks. Grooving can be found by running your thumbnail over the surface, allowing you to tell if the disc is smooth or worn. Another thing to look for is discoloration or bluing. This condition means that your discs are overheating, and that's not good. Also, check for the proper thickness of the disc. This measurement is stamped on the disc. Now take a look at the calipers. They should be clean and free of leaks. Next, check the brake pads. A good rule of thumb is that if they've worn thinner than a nickel, it's time to replace them. At this point, it's also a good idea to t ake a look at the brake lines. Besides searching for obvious leaks, double check brake line fittings. Also look for cracking, weather checking, or any other signs of wear. Remember, these parts are mostly rubber, and you should expect to replace them from time to time. Now check the rear brakes. Start with the disc, then move to the caliper, and finally look over the brake lines and connections.

Now that you've given your disc brakes the once-over, it's time to check the brake fluid. Make sure the bike is upright and level. Then remove the master cylinder cover. Now inspect the rubber diaphragm gasket for tears or worn spots. Next, take a look at the fluid and fluid level. It should be free of water and debris. If you need to add some fluid, remember, all fluids are not created equal! The two major types of motorcycle brake fluids are DOT 3 or 4, and there is also DOT 5. Most metrics use DOT 3 or 4, which are hydroscopic. This means they attract water, so always use a fresh, sealed bottle. They are also corrosive to paint, so wipe off any spills immediately. Most American cruisers use DOT 5. It's synthetic and non-corrosive, but NEVER mix it with DOT 3 or 4! The resulting chemical concoction will utterly destroy every rubber component it contacts! Once you've filled the reservoir to manual specs, replace the gasket and cover. Keep in mind that many master cylinder covers are directional, so make sure you can read the lettering while seated on the bike.

Now, how about some questions and trouble-shooting? If your brakes squeal, does that mean you need to replace them? Well, not necessarily. Modern brake pads are semi-metallic in composition. This could lead to a slight squeal even when they are new or slightly worn. However, a squeal could also be an indication of metal-on-metal, and replacement is imminent. In either case, it would be best to have your dealer check it out. Okay, what if your brakes feel "spongy," or the brake lever can be pulled back to the bars? Chances are that your brake lines have air in them and need to be bled. This task is also a job for a certified mechanic at your dealer. What do I do if I want to upgrade my braking system? Well, if better stopping is high on your list, the options are practically endless. Most bikes can be upgraded to floating discs or calipers, or both. There are multi-piston calipers available also with plenty of stylish chrome. In other words, you can improve performance and cosmetics at the same time. Just ask your dealer what kinds of options are available for your bike.

So, here is a quick checklist. Know your bike's braking system and inspect it often. Check the discs for wear and the calipers for leaks. Make sure floating parts are secure but flexible. Use the nickel test for brake pad thickness. Go through the brake lines looking for leaks, cracks, or worn spots. Check your brake fluid regularly, and never mix different types of fluids. Finally, if your brakes squeal or feel "spongy," get your bike to your dealership and a certified motorcycle mechanic.

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