Road Caliper Brakes
Most modern road bikes use road brakes, or caliper brakes, which are a sub-category of rim brakes -- designs that slow and stop your bicycle by forcing rubber pads against the rim of your bike to create friction.
Caliper brakes function as a single unit, mounted to your frame by a lone bolt, that pivots when the brake leversare pulled. These designs are useful for road bikes because they provide a great balance between stopping power and delicate modulation of the amount of power you can apply.
How do they work?
In the most common design, called dual-pivot side-pull caliper brakes, the braking cable enters the calipers from the top of one side of the mechanism. When the brakes are pulled, one arm pivots from the center and the other pivots from the side, forcing the brake pads into contact with the rim of the tire.
Caliper brakes provide good stopping power, low weight and simple operation. While they can be knocked out of alignment, adjustment is easy and straightforward. Overall, they make a great choice for road cyclists looking for a good set of brakes. Caliper brakes are generally not used on mountain bikes because the length of the arms that would be necessary to reach around the large, knobby tires would compromise the stiffness of the braking action.
Types of road caliper brakes
There are three main types of caliper brakes on the market today. Make sure to choose the right type for your bike, or at least know what you have in place when you are going to make a repair.
The first type is the single-pivot side pull, which attaches using a single bolt and pivots around this bolt. Single-pivot side pull brakes provide excellent stopping power but can have centering issues that prevent both pads from engaging on the rim at the same time.
The second common type of caliper brake is dual-pivot side pull, which uses an asymmetrical design to provide good centering abilities as well as strong braking, making them preferable especially when long reach brakes are required. This is the most common form of caliper brake on the market today.
The third and least common form of caliper brakes is the center-pull design, which was common in the past but has been largely phased out. As the name implies, these use a centrally-located brake wire instead of a side pull, and are still found on some bikes where particularly long reach is required.
Pricing and quality
Road brakes come in a wide range of prices. The top end of the price range comes in at well over $300 in price. These models, which include the high-end Shimano Dura-Ace series, provide ultra-strong and precise stopping power with the lightest possible weight and sleekest profile.
The low end of the caliper brake price range comes in the $20-$40 range and isn't able to match the performance of the high-end models. However, if you are a more casual rider or never ride at extreme speeds, brakes in this price range can fit your needs admirably.
Caliper brakes come in a variety of different sizes. Each size has different lengths of arms, which need to be matched to your frame. Frames with more space between the rim and bolt-attachment point for the caliper brakes will need longer arms, while a shorter distance here requires shorter caliper arms.
The length of caliper arms usually falls between 39mm and 108mm (in extreme cases). The most common sizes on modern bikes are in the range of 39-49mm, since modern road bikes tend to disallow the use of fenders by having very little spacing between the fork and the wheel, and since a shorter caliper arm length (also called "reach") gives better leverage and lower flex while braking.
How to use caliper brakes
In general when using caliper brakes, your front brake provides the majority of your stopping power. This is because when stopping at higher speeds, your momentum is all on your front wheel; the rear wheel simply has no traction to stop with.
Of course, when using the front brake as your main stopping power, it is possible to flip over your handlebars. Those of us who haven't experienced it have heard horror stories. However, it is very possible to learn how to use your front brakes to stop quickly and powerfully.
Practice using your front brake in a parking lot, and start with low speeds to learn how to use them effectively and safely. One tip: use your arms to brace yourself on your handlebars, and keep your weight back on the seat and towards the rear of the bike. This is one of the best things you can do to avoid going over the top.
Caliper brakes are mounted on the fork crown or brake bridge of the frame via a single bolt. This should be tightened securely to make sure your brakes don't rattle loose.
Repairs and adjustments
Over time, caliper brakes on road bikes can start to lose their alignment. Luckily, adjusting them is easy. Check out our tutorial on adjusting road bike caliper brakes to learn how.