I too had the question of how tight the wheels should be when building. What I found to be a good tension was tight enough to take the wobble out, and then just a tad tighter to keep things in control. You still should be able to spin the wheels with minimal force. They will not spin freely at that point. There is a small window on spinning smoothly under control and binding. If there is wobble, they are too loose. If they spin freely when you flick them...too loose.