Hi, my name is mykal. I have been unicycling for about a year and 1/2 I was wondering what kind of unicycle the people use in the video and how they got smooth tires. 
Most use a 19" trials. 2.5" wide tires
Shave off the tread w/a belt sander. A Tryall resonds best to shaving. Rolls a bit more smoothly, a bit lighter, and foot on tire tricks are a bit easier.
Personally I wouldn’t do it. I don’t think shaving helps THAT much and cuts the tire’s life in half.
Another option is a true 20" wheel like the KH Flat. And use regular smoothish BMX tires. (Max width available = 2.35")
the blue one looks like the Kris Holm 19" long neck. The white one looks like the impact 19" trials. Smooth tyre is probably just wear and tear.
I didn’t watch much of the vid but the tire on the uni at the beginning was DEFINATELY shaved.
Hello Skilewis, you’re probably correct. I didn’t get to read your post until after I posted my reply. BTW, the owner should buy a pair of shin guards. His shins are shredded. lol !
Hey, in case you didn’t notice I replied in your other thread.
thanks Ill makesure to sand my tires
where did you find the KH Flat? can you send a link?