Clattering brakes on Liv Envie My 2017 Liv Envie has 'V' style proprietary brakes (Giant Speed Control). Recently they've been making a clattering sounds when they engage the carbon wheel. This is happening on both the front and back wheels. Any ideas why?

Thank you!
Brakes make sounds when:


Pads are worn out and metal plate of pads makes contact with the wheel.
Pads or wheels are dirty and greasy. 
There is some loose part in braking mechanism. 
Pads are rubbing against the wheel. 
Overheating caused by long and hard braking.
Pads are wet. 


To fix each of problems listed above do this :


Replace the pads. 
Clean pads and wheels with some brake cleaner, degreaser or rubbing alcohol. 
Tighten the loose part. 
Straighten the wheel or align the pads. 
Try to not brake if isn't necessary, or get better brakes that could handle the heat better. 
If you are riding in wet conditions there is nothing you can do about it.