I just finished building a new RC18B2 from the B2/T2 kit. It all went together fairly easily but it doesn't roll very well (like there is a hung bearing or something). I checked all the bearings as I put it together and they were all fine and I have the belt tensioner for the front belt set at its loosest setting but it rolls like the brakes are always on. I know new belts tend to be stiff but this is much tighter than I'd expect. Any suggestions for what to look for before I start tearing stuff off?