And now for something completely different....
I recently had my X500 jacked up in the front doing some routine maintenance and I noticed how effortlessly the front wheels would spin. I played around a little and discovered that the tire is so well balanced and the bearings are so smooth that the tire will actually balance itself on the weight of the valve stem. The tractor has about 250 hrs on it. JD must be using some pretty good bearings on these wheels.
The same thing occurs on the left and right front tire. I've never seen this type of precision from a garden tractor tire/bearing so I just had to record a video and share. :-)
2013 John Deere X500 Front Wheel Balance and Bearing Demonstration - YouTube