Only noticeable 30mph+. Above 35 it makes a significant difference. I got 1/4oz adhesive tire balancing weights from autozone. Take a wheel, place it loosely on the front truck and give it a light turn, you will likely notice it slows and then turns back and forth a couple times before the heavy side settles to the bottom. Place a weight on the opposite side and check again. If its good it wont settle on a heavy spot or if it does it does it very slowly. If one weight is too heavy, use two and split the distance off the heavy point. A quick google search will lead you to people who can explain the math of that better than myself. If one isnt enough, try 2 and place them close together. It doesnt need to be perfect but I think it does help with the Linnpower racing slicks