Disk breaks vs. rim breaks?

Question

What is the differance? What do i have? i have a mountian bike and there are two pads one on each side of the wheel in front and back. when i sqweez the handle the pads push together.

Answer 1

Disc brakes have a small metal plate (disc) attached to the center of the wheel (this is called a hub). There is a squarish gizmo (caliper) attached to the frame that straddles the disc.

Rim brakes also attach to the frame but the caliper reaches over the tire and the pads squeeze against the big hoop that holds the tire (the rim). There are other types of "rim brakes" but I am not going to confuse you.

Answer 2

You have the rim V-Brakes.

Disc brakes are similar to motorcycle brakes, where you have a metalic disc on the left side of the bike and is attached to the hub

Answer 3

If the pads are on the outside rim of the wheel you have rim brakes.  If the pads are on a disc attached to the centre of the wheel you have disc brakes.

Hydraulic disc brakes have a lot more stopping force, mechanical disc brakes and rim brakes are about the same.

Answer 4

you have rim brakes.

These are some basic brakes:

Rim Brakes:

http://www.sram.com/_media/images/avid/r...

http://www.adventure-cycling-guide.co.uk...

Disc Brakes:

http://www.rideyourbike.com/images/avidd...

http://www.rollanet.org/~conorw/cwome/ga...

Answer 5

Rim brakes, also known as V brakes, are cheap. and unreliable in the water... Disk brakes are reliable in all weather conditions... Disk brakes tend to get hot when used a lot, and can squeak loudly, but the brake is smoother to stop... but it can be firm when needed. Disk brakes can cost 300 dollars more, than V brakes... I like disk brakes since they seem more reliable

Answer 6

Disc brakes require disc hubs on the wheels to accept the disc rotors.  This all adds weight to the bike.  

You have v-brakes, which are fine and have been around forever.  I have them on my bike and love them; they are easy to adjust and simple to replace pads, etc.

Answer 7

You have rim brakes. They are the cheapest of the two. They're light, mechanically simple, easy to maintain, and very powerful. However, they perform poorly in wet weather when the rims are moist. This problem is less serious with rims made of aluminium, found on more expensive bikes, than on those with steel or chromed rims. They are also prone to clogging with mud, particularly when mountain biking.

You most likely have one of two, (The Cantilever,)  direct-pull, and linear-pull brakes have each arm attached to a separate pivot point on one side of the seat stay or fork just below the rim. This solves the problem for standard callipers on wide tires (such as those on mountain bikes) where the long distance from the pivot to the pad allows the arms to flex, reducing braking effectiveness.

The traditional cantilever has an L-shaped arm protruding outwards on each side, with a cable stop on the frame or fork to hold the cable housing and a straddle cable between the arms similar to the centre-pull brake. The cable from the brake handle pulls upwards on the straddle cable, causing the brake arms to rotate up and inward and squeezing the rim between the brake pads.

Linear-pull brakes (sometimes referred to by the term "V-brakes") mount similarly, but the arms extend straight up, and the housing is attached to one arm and the cable to the other, similar to the cable attachment for side-pull brakes. They are generally more powerful and easier to adjust than cantilever brakes but require a smaller gap between the brake pad and the rim surface. They function well with the suspension systems found on many mountain bikes because they do not require a separate cable stop on the frame or fork. Due to their higher mechanical advantage, linear-pull brakes require levers with longer cable travel than levers intended for caliper brakes or traditional cantilever brakes.

There are two main types of disc brake: mechanical (cable-actuated) and hydraulic. Mechanical disc brakes are almost always cheaper, but have less modulation, and may accumulate dirt in the cable lines since the cable is usually open to the outside.

Hydraulic disc brakes use fluid from a reservoir, pushed through a hose, to actuate the pistons in the disc caliper, that actuate the pads. They are better at excluding contaminants, but are difficult to repair on the trail, since they require fairly specialized tools. The brake lines occasionally require bleeding to remove air bubbles, whereas mechanical disc brakes rarely fail completely.

Also, the hydraulic fluid may boil on steep, continuous downhills. This is due to heat build up in the disc and pads and can cause the brake to lose its ability to transmit force ("brake fade") through incompressible fluids, since some of it has become a gas, which is compressible. To avoid this problem, 203 mm (8 inch) diameter disc rotors have become common on downhill bikes. Larger rotors dissipate heat more quickly and have a larger amount of mass to absorb heat.