Why do heavier skaters need softer wheels?

It's pretty obvious that people of large build won't be using the same wheels as the average build people. Indeed the bigger you are the more you need grip because the centrifugal force drags you to the outside when entering a corner. Thus the bigger you are the more the centrifugal force affects you and so the more you need grip to pop of the corner and generate more speed.

The only way to get more grip is to use the snap of the wheel: the rebound of the wheels when pushing on them. This will provide you with the required grip. There are various ways of getting more bend. You can use a softer hub or a softer tire.

Inline wheels, with a thicker inner ring, pop more. Larger and heavier skaters will probably be using F or XF wheels and the average to lightweight weight people the XF or XXF.

Diederik Hol, CEO, and designer of Cádomotus says: "Many skaters think that more weight means bigger footprint and more boggy roll hence why I choose XXF over XF, but this is not correct if you want to go fast."

This would only make sense when you just roll and not push! When you want to go fast, you need to push, for which you need grip. Heavier skaters need more grip.

Yann says: "Indeed technically heavy people should increase the footprint when standing on the wheel but actually, it does not affect the roll. Because you generate more speed while pushing than rolling. The larger footprint isn't an issue. If you want to generate more speed you need more traction for a higher push efficiency."