disk brake shudder

[Al223]

Hello!
why does my front disk brake on my bike shudders under harder braking and vibrates the whole front of the bike? what are the causes and can you tell me any remedies?
Thank you!

[Vorpal]

Is this a new bike? Did you follow the bedding in process?

What type of brakes are they? If it's not a new bike, is it new behaviour?

[barrym]

I would suspect the head bearings are loose. While stationery hold the take on and see if you can feel movement whilst moving back and forth.

[Brucey]

various things will make the symptoms worse, but the most likely underlying cause is a fault with the disc itself;

1) contamination and/or
2) thickness variation and/or
3) disc runout (warped disc)
4) disc not mounted to the hub correctly
5) hub bearings loose

On a front disc a thickness variation that is unmeasurably small (even with a good quality micrometer) is enough to cause severe judder. It may be accompanied by/caused by the other things in a kind of hellish symbiosis.

So if you want a high chance of curing it quickly and simply, new disc and pads please. However if there is contamination from lube leaking out of a hub, or oil leaking from a faulty hydraulic system, or the disc mounting is bad, the problem will recur.

If you have a little time on your hands and are willing to try some stuff out, try

a) cleaning the disc and replacing the pads, and/or
b) swapping the front and rear discs

A thickness variation is tolerated better on the rear, because there isn't a resonance that can be 'excited' in contrast to the fork which can spring back and forth.

Don't ride too far with a bad fork judder; this can cause the fork and/or frame to fail in a relatively short period of time.

cheers

[Gattonero]

Hello!
why does my front disk brake on my bike shudders under harder braking and vibrates the whole front of the bike? what are the causes and can you tell me any remedies?
Thank you!

That is not enough information, at all.

To avoid speculation, it needs to know at least if that was original equipment or retrofitted, brand and model and size of the brakes, and type of forks, plus rider setup.

Juddering can come form many causes, of which the type of forks is often the main culprit.

[rmurphy195]

Mine are TRP Spyres, and they just needed proper adjustment of the mountings to get the judder to disappear, using the vidoes supplied by TRP - the calipers weren't quite square-on https://www.youtube.com/watch?v=wPTK0yEUI5s

Maybe even with a different brake you could have this problem?

As others have said, state what brakes you have