ABOUT DISC BRAKES
- Without doubt the component that gives our members the most grief.
In this article we will try to explain the problems and be as constructive as possible. Even though it's hard.
This is not a scientific article, but 100% based on our own professional experiences. An experience that is based on the members we have and the bikes they buy.
What are disc brakes?
Disc brakes have handles on the handlebars, like most types of brakes. These are connected to the brake mechanism itself in one of 2 ways: Either via a wire or via hydraulic pressure, i.e. brake fluid in hoses that activates the brake mechanism when you pull on your handle - We call the handle a brake lever.
There is a ​distinction between mechanical disc brakes and hydraulic disc brakes. However, both types works by a brake mechanism, which we call a brake caliper, that clamps 2 brake pads together around a thin brake disc. This disc is mounted on the wheel. By squeezing this, you stop the wheel.
Here is a picture of a disc brake:
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What's the problem?
Daily we meet schreeching disc brakes that are very noisy when in use. Often without some of the components being worn. Good brake pads and discs, also called rotors, are expensive to replace, and we consider it a problem to have to replace something that has not been worn down.
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But the violently schreeching sounds can be very annoying.
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Why does this schreeching occur?
Theoretically possible reasons:
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Incorrect setting or installation
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Brand new pads/discs which have not yet been "bedded in", i.e. the new parts must first adapt to each other.
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Crooked brake disc
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Cold and damp weather
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Metallic pads(organic pads are less noisy)
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Cheap and bad brake discs
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Leaky hydraulics
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Pollution.
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​Our experience
If your brakes schreech at the start of your ride, especially in winter, it's probably because of the cold - the brake heats up quickly if you use it. If it is due to water it should also be temporary.
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However - in our experience - schreeching is almost always due to pollution. Sometimes due to a leaking caliper that drips brake fluid onto the disc.
Often pollution contaminates and penetrates the pores of the material in both discs and pads.
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You can do something about it
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The simple way to fix the problem of contaminated brake pads and discs is to change them. It's just expensive, and a shame if they're not worn. The worst thing is that the problem quickly reappears.
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You are driving in a city with pollution in the air. The water and dust that sprays up from the ground also contains oil residues etc. If you wash the bike, there will probably also be residues of various things on the discs and blocks. It cannot be avoided. And yet it can be remedied.
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You can park the bike in a closed shed/basement. It limits some of the pollution.
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You can drive many kilometers every day, drive fast and brake hard. Thus, the brakes will clean themselves and they will heat up, which is relevant when the weather is cold.
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You can try various chemicals and agents that promise to solve the problem. To date, we have not found a remedy that works for more than a few days, once the pads and discs have been contaminated.
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You or we can remove discs and pads, grind them and clean them. But again, it is not usually a solution that lasts once the problem has arisen.
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If we change your pads and discs because of schreeching brakes, it is important that you follow the advice here so that the problem does not reoccur. However, 19 out of 20 of our customers also have bikes with very cheap brake discs, so the upgrade we provide will also help somewhat.
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Conclusion: What do the mechanics themselves do with their own disc brake bikes?
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Those of us who have short distances and no possibility of indoor parking, we live with the problem. We just annoy the others in traffic with our noisy brakes, as there is nothing to do.
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Those of us who drive far, drive fast and furious, and cycle every day, never have problems with screeching disc brakes. Only the first kilometer when it's cold.
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Our conclusion is therefore that commuters with a leisurely pace and short distances in a polluted urban zone should stay well away from bicycles with disc brakes. For those who have long distances and drive to, disc brakes are good because of their stability and powerful effect.