Yes feathering is visible to the eye but can be difficult to see if you don't know what your looking for. If you run your hand over you tires tread first one direction around the tire and then run your hand the opposite way around the tire you'll feel the difference. If your tire is feathered you will feel the change in elevation of the individual tread blocks. If your hand runs smooth one way and the tread catches it and doesn't permit your hand to slide as smoothly the opposite direction your tires would be considered feathered. Judging solely from the info youve provided I'm guessing that its either wheel balance or feathering on your tires. This site will explain everything you need to know about your tire wear. http://www.geraldstires.com/Services.../Tire.htm#Tire Wear

 

Great site man, thank you!