GetGeared Guide To Motorcycle Brake Pads
Safety note: To remove/fit brake pads and to bleed/refill the hydraulics free of air requires technical know-how at professional level – GetGeared recommends that brake pads are only exchanged by a competent mechanic!

THE BASICS ABOUT BRAKE PADS

Motion into heat: A motorcycle stops by the brake system converting the kinetic energy (force of motion) of the vehicle through the brake disc to heat. The faster the heat build-up and the faster the cooling properties of the brake disc, the more efficient the brake system. And in real life, this has to work predictably across a whole range of situations including tapping the brakes lightly to descending the long road down from a mountain pass.

Speed matters: The kinetic energy, or heat generated, grows exponentially as speed increases. If you double your speed, the kinetic energy set free quadruples!

The key criteria for choosing brake pads:

  • Continued and controlled friction performance along the thermal continuum from cold to very hot and across different driving conditions from dry to wet
  • Stability under high pressure conditions and good bonding of the friction compound onto the backing plate
  • A thermal barrier between pad and hydraulics, preferably a ceramics underlayer
  • A good life span under normal usage while delivering continuous friction when required
  • Fine and evenly distributed metal particles for sinter or sintered pads
The Different Types Of Brake Pad
GetGeared offers a choice across the two main types of brake pads which are distinguished by what they are made of:

Organic (or non-asbestos) Pads:

This type of pad is made by mixing non-asbestos fibres, such as glass, rubber, carbon, and Kevlar, with filler materials and high-temperature resins. The resins act like a thermo-set plastic, which holds the components together like glue. They can have a small proportion of metal and are then occasionally called ‘sintered’.

  • Largest market share among brake pad types
  • Lower brake disk wear
  • A softer bite point and therefore easier to control
  • Softer compound which creates less noise, but can wear faster and create more dust.
  • Thermal performance to 800deg C
  • Longer bed-in time required
  • Prone to glazing when standard thermal performance limits are reached

Sinter Pads:

These pads have a very high metal content. Sinter pads heat up more quickly and run to a higher temperature. With more kinetic energy converted more quickly to heat, they are very effective. It is important how they are made though: Run your fingers over premium sinter pads and you feel a smooth surface of finely cut, evenly distributed metal particles do the same with budget pads and you get a rougher surface that acts like wire wool on your brake disc.

  • Higher friction levels, which are maintained in wet conditions
  • Low tendency to ‘fading’ brake performance in extreme conditions
  • Shorter bed-in period
  • A defined bite point
  • A higher running temperature, also affecting the brake disc surface
  • Not suitable for all brake discs (cast iron) or callipers
  • More prone to suffer corrosion
  • Brake fluid requires more frequent inspection

As a very general rule, sinter pads perform best on steel brake discs and organic pads tend to be kinder to cast iron discs.

GGBrakePadSection

Common Brake Performance Questions
1. Temperature continuum & brake fade

A brake pad’s comfort zone of operation is framed by the temperature range in which the pad is most effective. A great brake pad is a compound of materials, where individual elements of the mix are always effective at delivering friction regardless of the temperature; one material transitions into effectiveness while another material is fading away; all without the driver feeling any difference in the brake lever. When a brake pad starts to operate outside of its ideal temperature range, you can experience ‘brake fade’.

There are three types of brake fade:

The first is the conventional burning off of resins as the pads are bedding in. This is known as ‘green fade’ and occurs when gases from burnt resins are trapped between the pads and discs. When this happens the pedal feels firm but the motorcycle will not stop. Ensure that you do not enter situations that require strong braking when the pads are newly fitted!

The second type of fade is when the pads are forced to work outside their temperature continuum. This can happen more easily when inadequate or inappropriate brake pads are fitted and leads to excessive wear and poor brake performance when you need it.

The third type of fade is ‘glazing’. This is when the resins, which soften during active braking, then cool and solidify on the friction face of the pads. This glazed surface is hard and slick, and will not deliver the same level of friction as an unglazed pad.

2. Brake squealing

Don’t blame the pads! Brake squeal is caused by vibrations between the pad and disc, usually because the pads cannot move freely back and forth in the calliper. When the vibrations are in an audible range, you hear a squeal-like sound because of the rotation of the system. Providing the calliper and the brake disc are not damaged and properly fitted, unlubricated metal-to-metal surfaces within the calliper or excessive dust /glazing are to blame.

To keep your brakes clean, GetGeared recommends: WD40 Brake Cleaner

To keep your calliper free from salt and corrosion and therefore aiding the free movement of the brake pad, GetGeared recommends: PROCYCLE Brake Anti Squeal Paste

3. A soft handle

You should be able feel clearly the bite point of the brakes when depressing the handle/foot lever. If the feel is soft or spongy, more likely than not it means that air has crept into the hydraulics or worse, the brake fluid has congealed. You should get a qualified mechanic to bleed the system and refill it with new brake fluid.

GetGeared recommends: Petronas brake fluid

4. Pad taper

Pads often wear unevenly, usually with the front wearing first. This may be to do with alignment or faulty mounting of the disc and /or calliper, but the most common cause is that the front end of the brake pad tends to heat up more than the rear and as a consequence wears slightly faster. However, if the pads show a strong taper immediately seek the advice of a qualified mechanic.

5. Disc wear

Over time brake pads will carve a channel into the brake disc. This process is accelerated vastly by the use of budget brake pads (e.g. using low cost Sinter pads whose metallic structure is rough and acts like wire wool each time you brake), inappropriate brake pads for the disc type, or excessive grit embedded between the brake disc and pads. When a defined ridge has developed, brake discs must be renewed not least because the next set of brake pads will find it near impossible to bed in. Brake discs are expensive and it is worth insisting on high quality pads at every service and to keep the brakes clean especially during winter.

To keep your brakes clean, GetGeared recommends: WD40 Brake Cleaner

 

 

LEAVE A REPLY

Please enter your comment!
Please enter your name here

Sign up to our newsletter!