A spin can be instigated by pushing off an object, such as a signpost, a person,
or what is pretty cool, another unicycle, if the two of you are riding in
opposite circles (i.e. like a round eyeglasses or a figure 8) then you can do
all sorts of things when your two paths intercept. You can each push off each
other and you both can do a 180 or 360 degree spin, or you can grab hands and
the two of you can do some very interesting two person spins. one person stays
immobile while the other spins around him.
Good luck and have fun. I cannot do a spin unaided, but I often push off an
object as I ride by and do a 360, sometimes successfully!
doug williams freezing cold snowy slushy salty montreal