[atoav]

In skateboarding people tend to use angled riser pads to adjust the kingpin angle. As a side effect these riser pads can (ever so slightly) absorb hard shocks and decrease the chance of a wheel-bite (when your wheel comes into contact with the wood of the deck and stops you apruptly). This is not necessary with most longboards as they usually have a higher clearance, or even cutouts at the sports where wheelbites would occur. In street skateboarding the tradeoff is a little different, because the area where wheelbites occur are just next to the area "the pocket" you utilize for nearly all flip tricks. Also taking wood away there would have a negative impact on stability so street skaters would rather live with wheel bites than sacrificing wood area there – or as mentioned use the stiffest pushing you can find, use riser pad, tighten the trucks or similar.

[gabereiser]

As a previous skateboarder, the sweet spot is having full weight on a corner and having about 5mm of space between the wheel and the board. Wheel diameter also plays into the equation. Smaller wheels are used for looser KPT truck setups to reduce the wheel bite mark while increasing the truck turning capability. Risers further this difference. A standard park/street setup is different than, say, a downhill setup or what you find at your local department store. 48-52mm wheels instead of 56-58mm.

Longboards use larger wheels and wider trucks to clear the board of any wheel bite. Some even cut out that area of the board. For skateboarding, you need that area for stability, flip tricks, and landings.

The physics of it all is what’s so awesome about it.

[xodjmk]

About Zero people use riser pads in modern skateboarding. Nobody cares about wheel-biting either, even with loose trucks. if you wheel-bite and fall, you failed to land your trick. The goal is to land 'bolts', as kids say. (Source - any skate video)

[rhodorhoades]

I skate risers with tight trucks. As parent suggested, it helps with stairs and drops.

[atoav]

I skate riser pads, that is more than zero.