First of all, look at a picture: 72mm belongs to the big wheel and 60mm belongs to the small wheel.
In fact, what you are asking is only one aspect of the wheel, and the other is the hardness of the wheel: there are generally hard wheels and soft wheels.
In terms of size alone, it is the diameter you said: 72mm and 60mm, because the big wheel is fast and not suitable for beginners, and 60 is a special wheel for small fish dishes.
Then let's first compare the difference between hardness and wheels: that is, the feeling of use:
If the same size is 60mm, for example, the hard wheel is fast, but the shock absorption is poor; The soft wheel is slower, but when the road surface is bad, it will make you down-to-earth and choose according to your own interests.
So if you are a beginner, it is recommended to consider the diameter of 60 mm After all, 72mm is not only expensive, but also requires technology. In addition, after the size is determined, choose soft wheel or hard wheel according to your own use characteristics, and generally choose the original hardness of small fish plate. After all, it was ordered by the manufacturer.