I can't seem to get my rear brake to work. It was working fine one day, then after a weekend of riding it doesnt work. I worked on it awhile and had it aligned really well, but it still didnt work. I think the rotor may be contaiminated, so I was going to get some alcohol to clean it. Also should I try to clean the pads too when I clean the rotor. If the rotor is contaminated will I have to replace the pads anyway? My front pads are fine and it looks like I have enough pad left in the rear. Thanks, any help will be good, I want to ride, so I got to get this fixed.