I recently “invested” in some 2.3mm thick disc rotors from Ali Express. My first experience of them was yesterday when once bedded in they stopped me ok, but by crickey they are noisy! The noise seems to be related to heat as first application on a run is quiet but they get noisier the more they are used before getting a chance to cool down on the winch back up.
It’s Shimano SLX brakes with new stock pads (I assume resin).
What does the hive mind think I should do to shut them up?
Were they cheap unbranded rotors or branded knockoffs? It might just be they’re rubbish. No chance you’ve contaminated them?
Meths then wet and dry sandpaper on the discs. Dremmel your pads. Squeals go by by.
Check alignment
I would lightly sand the rotors and pads, clean with washing up detergent and hot water and try bedding them in again. Quite possible the rotors were contaminated from the manufacturing process and that contaminated the pads.
If the noise is coming and going with heat cycles then the heat is bringing changes to the pad co-efficient of friction. The change in co-efficient of friction modifes the stick-slip behaviour of the pad and that creates a resonance in the disc.
Your most likely 'fix' will be a different pad material.
I run sintered pads on bikes simply because they are more consistent and more tolerant to dirt/water/shit etc...
Right, I've cleaned the rotor and pads with IPA and sanded the pads, which are actually D02S sintered pads not resin as first thought. Just need a chance to test them now.
Don’t forget to bed them in properly again. Good luck
