Everything that touches the steps with the Hercules is soft rubber. We have rubber wheels, rubber V-belt glide belts, and soft polyurethane lifting feet. The V-belts maintain contact with the step, although they do no lifting they prevent the Hercules from scratching the steps. The dual lifting feet on the Hercules stairclimber put the same amount of pressure on the steps as the large rubber wheels do. This is because they are the same width as the wheels and have the same amount of surface area. It is interesting to note that some of the older Hercules's only had a single lifting foot in the middle rather than the two that we have now. The reason that we changed is so that the operator wouldn't have to balance the load in a sideways direction. However, there are still a lot of these older units still in use and they still work fine with no damage to the steps.