My heavy bike (~15 kg) has thick wheels, the rim width of each is about 3 cm. Accordingly, the tires are also thick (~4.5 cm). Unless the tires are fully pumped up, the bike is difficult to ride and is considerably slow (due to significant traction).
I am thinking of replacing the wheels with thinner ones. Is this possible in principle? If so, what issues have to be considered before doing that?