wrote in message
...
I bought a cheap bike at WalMart today.
etc.

What everyone else said, plus this:

It's entirely likely there's something truly fundamentally wrong with the
way the bike was assembled and the brakes installed. Like the pads are
missing, or the brakes are on the wrong side of the fork, or the fork is
backwards, or something else so stupid you probably won't believe it when
you learn what it is. Aside from their innate compromises, *mart bikes are
often assembled by people with no prior experience or training in the task.

Go to one of the sites mentioned, parktool or sheldonbrown, and carefully
compare the photographs of properly-installed brakes to your brakes.

Then think about what else might have been botched in the assembly of your
bike, and ask yourself if it's still a bargain if it's so dangerous you're
afraid to ride it.

RichC