Screeching and vibration from front disc .. help please

[nickinbattle]

Front Disc brake(Shimano) makes dreadful noise/vibration just at the ‘bite’ point where it stop the wheel (final 2 or 3 cms of rotation on the rotor !

Only started a month ago No luck in sorting it ! .. have had pads, rotor and caliper all replaced and it makes very little difference (all are clean, aligned and functioning as they should)

Absolutely no problem on the rear.
Don’t know what to do or try next. Help please 😊

(someone did suggest its vibration coming up thru the forks into the head and its loud as it travels thru bike frame tubes .. head not set up properly or worn ? )
Nickj

 

[JayKosta]

it could be the head tube bearings (or maybe even wheel bearings).
With bike fully stopped and front brake held tight, can you feel or hear any 'ticks' or movement, when you try to push the bike forward & backwards?

 

[nickinbattle]

Hi Jay ... Thankyou for your response ... really appreciate you taking the time, it helps enormously

Yeah so when I hold brake full on the bike will rock very slightly back and forth, I wouldn'.t have called it a tick, but I can hear it hittin/knocking against stops back and forward. Its subtle but it is definatly there, it feels and sounds like its in the head.
Do I assume that my next check is to get the head bearings tightened or even replaced. (I don't have the right tool for this, but I think I know a man who does !)
Here's hoping

Thanking you again

 

[RedheadDane]

Maybe it's a little demon living inside your bike, getting scared because you're going so fast.

 

[jmdirt]

Pad misalignment is the main cause of noise/vibration.

Is the wheel quick release? If so try a different QR skewer.

I would try a completely different front wheel since you have already replaced the brake components.

I would have the brake mounts faced.

The 'nock' that you describe could also be fork bushings, and they shouldn't cause braking issues unless they are completely worn out and you would notice that always not just under braking. While headset bearings can cause a vibration, they shouldn't cause a noise under braking unless they are so loose that you would notice that always not just under braking.