+1 To what @Gockie said. I was out on my 24" earlier. I do like that size. The tyre selection is more limited than 26", 27.5" and 29" but there certainly are some options.
Here is a picture of mine with a 24”x3” Felt “Thick Brick” (the brick part refers to the tread pattern, though given the size it is a fairly heavy tire )
My 24" is pretty basic with a cotterless hub and no brake, but it does have SHW 125/150 cranks, which is kind of unusual for a unicycle with this hub interface.
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