Rim brakes are simple. Rim brakes are fun. Rim brakes sometimes need adjusting. If you pull the lever and the brakes are still loosy goosey, then it's time to tighten up the tension on that brake cable!
On the back of the brakes, there's a threaded barrel assembly where the cable goes through. When the lever is pulled, the cable is tightened and the brakes engage to the side of the rim.
One way to increase tension on the cable is to screw the barrel assembly counter-clockwise. This will bring the tension on the cable into a range where pulling the lever engages the brakes. If the barrel assembly is loosened all the way and the brakes are still not touching the rim, the cable will need to be tightened from the other end.
- Down on the brake assembly, use a hex key wrench to loosen the bolt where the cable goes through. With the cable loose, close the brake pads tight to the rim, and pull the cable tight. TIGHTER! Ok, good. Now tighten the bolt down that holds the cable to the brakes. Finally, back up on the handlebars, screw the barrel assembly clockwise to adjust the cable to the right tension.
Now when the lever is pulled, the brake pads should engage with minimal travel! You now have properly functioning brakes. You're welcome.