Kutittaa

I'm buying a whole new break for my bike. My last mechanical brake somehow fell off.

Anyway I need a whole new setup I'm told and because some paint has dripped on the front and back brake discs the store I am buying from tells me that I need 2 new brakes.

Funny because I am only buying ONE break. (The front one).

So do I really need TWO new brake discs (one for front and back I am told) when I only need to buy 1 front brake?

On top of that, is a tiny bit of paint going to make the brake not work? I can barely see the paint on the disc!
Could I just leave it in a tin of paint thinner for an hour and then use it like new?

Thanks a ton!