In terms of the material used to manufacture the wheels, we distinguish between rubber and polyurethane (PU) wheels. Rubber wheels are generally slower and wear faster. On the other hand, they better absorb small surface irregularities (especially small stones) and slide a little less on wet surfaces, although this mainly depends on the compound used in the manufacture of the wheels. Roller skis with these wheels correspond in speed to cross-country skiing. Just like on cross-country skis, your skis can ride very differently depending on the wheels you choose. You can get fast rubber wheels that correspond to cross-country skiing on frozen snow. However, you can also buy slow wheels, which, on the other hand, respond quickly to wet snow. In short, the differences in the speeds of rubber wheels are huge. Thanks to the different speeds of the rubber wheels, you can compare the possible difference in performance when driving together =).