Wheels on minibot

In the manual, where it specifies exactly what parts we can use, the list doesn’t seem to include wheels. The wheels that came with the mini kit are part of the Tetrix components, right? Are we limited to those wheels? We don’t want to use these wheels, so I was wondering if we’re allowed to build our own wheels. We were thinking of creating wheels using PVC pipe and either rubber bands or non-slip pads. Is this allowed?

As long as your constructing your wheels out of the parts you described it would be legal.