How to fix bike brakes?

[olmue]

So...any bike repair experts around? We've all had to move up a size in bikes this year, and after MUCH looking, I finally found a used bike for my 13YO. Everything looks good on it (only three of the five gears appear to work, but the thing runs smoothly)--but the back brake is stiff, and doesn't actually stop the bike. You depress it, and the brake pads contract, but not tight enough to actually stop. Questions:

1. Is this the sort of thing a normal person can just fix? Or is it a bike repair shop sort of thing? (I don't want the bike repairs to cost more than the actual bike did.)

2. Do you just buy a whole new brake set? Or is it something like replacing the cable? (And no, I really don't know what I'm talking about by that.)

3. Or is it something where if I just spray enough WD-40 on the bike, everything will work smoothly?

4. Or do cables loosen up somehow? Should I be tightening it or something? 

I just feel like I don't know enough to know what questions I should be asking or what I should be even googling. (Yes, I'm aware Google exists. That's where I find videos of bike repair enthusiasts from Sussex, England throwing around jargon that I don't think even exists over here--it would sound mighty odd, let's say--and waving around bike parts that don't look like what's on this bike at all.)

I realize you can't fix my bike for me. But um, if anyone knows what questions I should be asking, I'm all ears.

Comments

[olmue.livejournal.com]

Thanks! We played around with tightening the cable down by the brake, and also replacing the brake pads. That seems to have helped the brake. Now on to the gear shifts...the shift thing you turn seems a lot tighter at one end than at the other, so maybe there's a cable that needs to be loosened up some in there. (Or maybe I just need to dunk the whole thing in WD-40!)