Roller skates -- or quad skates -- with adjustable trucks allow a rider to set the trucks at a desired stiffness. This adjustment determines how much weight is required to turn the skates when the rider leans right or left. Like the trucks on a skateboard, the back wheels twist to the outside of a turn while the front truck angles towards the inside of a turn. If the trucks are not tight enough, the ride becomes loose and uncontrollable. If the trucks are too tight, the skater cannot put enough weight on the inside or outside of his skate to turn.
Turn the skate over. Facing up, you will see two bolt heads which fit either a hex or Allen wrench. If your trucks are too loose, turn the bolts to the right to tighten them. If they are too tight difficult to turn, turn the nuts counter clockwise. You do not need to turn the bolts more than one turn at a time.
Put the skates on and do a few laps around a track or down the sidewalk. Test the stiffness of the truck pads by leaning hard to each side. If you are not happy with the performance of the skates, adjust them once again.
Adjust the front and back trucks at different levels of tightness if you are still not pleased with your skates' performance. If you loosen your front truck too much in relation to the back truck, your toes my dive every time you make a turn. In this case, tighten the front truck pads. On the other hand, if you cannot get your toes to get a grip and pull into a turn, but the heel of your foot falls to the side and you begin to skid, tighten the back truck pads.
Adjust the truck pads regularly. You may discover that by tweaking them -- even though you're happy with the skates' performance -- a precise setting exists that not only improves your ride, but also increases your comfort.