what your talking about is a DIRECTIONAL tire. those have a tread design which matters on which side they are mounted on. if you wanted you can dismount the tires and just flip it to fit the other side if you really want to rotate the tires, but it gets costly to do it like that.
you dont have to have directional tires and most tires have a standard tread pattern that you can flip flop to any side you wish. dont confuse asymetrical tires with directional tires either, asymetrical tires only mount one way and can be flopped around like normal.
if you're not happy with the tires you have now post up what you want from your tires, people love talking tires.
