What rim do you use?
And stop grinding it :lol:
Theres probably a perfectly good reason why your brake is not working (Y)
Maybe a slightly leaking calliper...thats leathal
too much tar on rim...overall makes your brake absoloute crap
brake pads not square to the rim.
I went though that the other week, no matter what pads i put on, the brake was rubbish :$
cheer andy