I'd got a Tilite Aero X a few months ago and did not realize that the front casters were too far raked back all this time. Last night I set them about straight up and down and now the front of the chair moves nice and freely, definatly a good adjustment to make. If your chair moves not very well on tight turns, check your caster fork rake!!! The casters don't seem to be fluttering as much anymore either when I go fast, still a little, but nowhere near as bad. I think some of it might be the wheels wobble a bit when you spin em, the bearings are tight and all, it's just both wheels are a little bit warped. Thinking about changing out to some soft roll 1.5 inch 5 inch caster, these ones are 1 inchers and too narrow for my taste. I like being able to go over grass and off road a little better, these 1 inchers are more prone to sinking in.