64, 72, 76 and 80mm wheels are the measurements for inline skates. 32x54mm, is the size of wheels for quad roller skates, where 54 mm corresponds to the diameter and 32 to the width.
As the diameter of the wheel increases, the vibration decreases and a higher speed can be reached. If it decreases, the speed will be lower. Lateral stability and driving will also be affected proportionally, the biggerr they are, the lower the balance.