I had a very bad tik tik tik noise when the brakes are not applied, the noise disappeared when the brake is applied.
I removed the brake caliper and checked the brake pads.
what you want to look for is the outer Brake pad ( most right when sitting on the bike)
It sits between two braces and hooks underneath them.
There is a spring that holds that brake pad in place.
If the brake pad is not 100% mounted correctly or there is some play between the brake pad and the spring, the brake pad will move slightly hitting every hole in the brake rotor causing the tik tik noise.
I simply re-installed the brake pad, paying some more attention, and the problem was solved.
I am sure that has been discussed before, but thought i post this again for anyone who has missed it...
