In article ,
says...

I have back pedal style breaks. They are very loose, and so it takes
a while to stop (have almost died many times because i couldn't stop
in time). Does anyone know how to tighten these breaks? I tried to
search the internet for a link on this, but to no avail.

If your bike doesn't have one already, get a front brake. If it does
have one, get use to using it. It will help you avoid all of those
near death situations.
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Alex