Brake Discs are responsible for providing the necessary friction to cause a vehicle to stop. High quality brake discs combine heat reduction with great friction. Usually made from materials such as cast grey iron, brake discs come in a variety of designs to suit different vehicles and driving habits.
Shaped as a flat, round metal piece, brake discs are attached to a vehicle's wheels, and they cause them to stop when the brake pedal is pressed, with the help of brake pads. As the friction required for this process inevitably causes wear in the long term, brake systems need to be replaced from time to time. Brake pads concentrate most of the wear, and they are cheap and easy to replace, while brake discs tend to last longer.
Sometimes there are two different kinds of brake discs in a single vehicle, as they can offer different advantages for either back or front wheels. On the other hand, racing vehicles pose a much greater demand on brake discs, and they usually feature more complex designs than standard car brake systems.
When buying new brake discs, there are a few considerations to take into account, including when replacing brake discs is recommended. Additionally, it is wise to compare drum and disc brakes, including details about their different uses and performance levels.
Different Types of Brake Discs
The brake discs included with stock cars usually have a one-piece design featuring a wholly flat surface. This type of design offers a good performance for standard driving conditions, providing sufficient friction, force, and heat-control for average-speed driving. In the case of racing cars, brake discs tend to feature grooves and cross-drilled holes, which greatly enhance their performance and durability.
Drilled and Slotted Brake Discs
When grooves are cut into a brake disc's surface, gas is dissipated, contributing to friction surface cleanliness and minimising wear. Likewise, slotted discs offer extra friction on the brake surface, while also helping them stay dry and cool and maintaining brake pads clean.
Drilling holes through brake discs can also enhance their braking performance, by keeping them cool and permitting ventilation; this system is seen in cross-drilled discs. High-performance drilled discs are commonly used in racing vehicles. While the system offers many advantages, it also involves a vulnerability to cracking around the holes. Some brake systems combine the advantages of drilling with the durability of solid models, featuring partial drilling into the discs.
It is possible to buy discs that feature both drills and slots, which provide a combination of great heat management, gas ventilation and friction,
Vented Brake Discs
Many brake disc designs are made of more than one piece. Vented rotors, which are commonly used on front wheels, are made of two friction surfaces that feature a network of vanes and posts sandwiched between them. This allows air to flow leisurely inside the disc, and the system of vanes forms a vortex designed to suck all of the hot gas and air away.
Vented discs offer cleanliness and durability, as well as excellent heat management. Vents come in different designs, such as straight or spiral. When vented discs are also cross-drilled and slotted, they can additionally offer a superior braking power.
As many cross-drilled or vented discs are aerodynamically engineered for either the left or right-side wheels of a car, it is important to take this into consideration when selecting these items for purchase. Moreover, as they take up more space, this type of brake discs can only be used in certain cars, so car models commonly determine the type of discs required.
Some manufacturers offer the option of adding zinc coating on brake discs.While stock cars usually feature steel discs, this metal is very vulnerable to water and salt. and it can easily rust. Brake disc rust is often harmless, but it can be visible on most wheel designs, creating an unattractive look.
Turning or Changing Brake Discs
As brake pads need to be replaced more often than brake discs, it is always recommended to have discs turned at the time of pad replacement. The surface of discs gets scored with the process of braking, and turning them can prevent pad damage, which can reduce stopping power.
It is possible to turn a brake disc once or twice before it becomes too thin and cannot be used anymore. If discs are turned beyond this limit, they can be subject to damage, such as cracking and sometimes even shattering. Therefore, it is very important to consult a reliable mechanic who can determine whether brake discs need to be replaced or not.
Drum Brakes vs. Disc Brakes
Originally, all cars were equipped with drum brakes. While disc brakes have widely replaced the former today, the majority of modern cars feature disc brakes on front wheels and drum brakes in the rear. Brakes work by transforming friction into heat and then dissipating that heat. Disc and drum brakes accomplish this in very different ways.
The Original Drum Brake Systems
Drum brakes owe their name to their round drum-shaped housing. Originally, this housing contained a mechanism that used pressure against the drum to slow a car's wheels. When brake pedals were pressed, a fluid transferred the pressure from the pedals into the inside of the drum.
This mechanism's main flaw was a proclivity to lose effectiveness in extreme conditions such as going down a hill, or slowing down from a high speed repeatedly. These conditions generated too much heat inside the drum housing, which the system had no way of dissipating.
Modern Brake Systems
Brake design has greatly evolved over the last decades. The rear drum brakes of today provide better stopping power than the disc brakes used 40 years ago. Since up to 90 percent of a car's stopping ability is given by the front wheels, modern drum brakes provide sufficient power for rear wheels.
While extremely high-performance vehicles may require disc brakes on all four wheels, especially when they are often used for racing, these are more expensive, and the majority of common cars do just as well with a combination of drum and disc brakes.
How to Buy Brake Discs on Ebay
There is a truly astounding variety of brake discs available on eBay. Whatever car make and model, brake disc type, and price range you may prefer, you are bound to find something among the site's hundreds of thousands of listings. Naturally, brake discs must correspond with car models, and this is the first criteria you need to apply to narrow down your search.
Once you have refined your search and can see only the listed brake discs that can work for your vehicle, it is time to select the brake disc types of your choice. If you are sure you would like "cross-drilled" or "slotted" discs, you can add these keywords on the search bar. At this point, you can start looking for the best set of brake discs you can find at the best available price.
The market for used brake discs is not as busy as that of new items, as this type of device suffers extensive wear. However, it is sometimes possible to find brake discs that are listed as used merely because they have been taken out of the box or taken for a spin. While it is generally not recommended to buy used brake discs, some very high quality items may have a long life, offering high performance and safety in the long term. If you are considering buying used brake discs, be sure to ask the seller about the use they have seen.
Whatever brake discs you may choose, it is always important to check seller reputation, postage costs, and return policies before making a final purchase decision. Asking the seller the right questions about their products can always save you some unnecessary trouble.
Brake discs are an essential part of motor vehicles. Present in the majority of cars as well as on motorcycles, they are heavily responsible for driving safety, as they are in charge of stopping a vehicle's wheels when the brake pedals are pressed.
Since they transform movement into heat, brake discs require effective temperature management. As efficient friction requires surfaces to be clean, ventilation is also a key aspect of modern brake disc technologies. Slots and cross-drilling can boost the performance and stopping power of brake discs. Vented discs offer superior ventilation, but they do not fit into all car models, as they take up more space than regular brake discs.
While drum brakes were used in all cars in the past, today they are generally only present in rear wheels, as the bulk of a car's stopping power must be concentrated on front wheels. Therefore, disc brakes, which offer a better performance than drums, are consistently preferred in the case of front wheels.
Although the life of brake discs can be extended by turning them, this can only be done once or twice before it is necessary to have them replaced. As brake discs can also be crucial for the look of a car, discs made of rust-proof materials are commonly preferred. Keeping all this information in mind ensures that buyers can find the right brake discs for their car.