Tires, Tubes, Rim strip
One of the biggest, easiest and cheapest upgrades you can do to is change its tire. On a unicycle all your weight is on one tire (unlike a bike where you have two wheels), so you need a larger volume tire. Tires for unicycles need to have strong side walls (i.e. high pressure tires).
Tires, Tubes, Rim, strip, Unicycle, Parts