does anyone know how to assemble 4" traction wheels. i need to put two on a axle and have two axles. does anyone know how to do this?
Andy Mark, IFI, someone else?
Specifying the wheel type always helps. 
AndyMark Appears to be assembled (maybe not treads)
For IFI
http://andymark.biz/am-0014.html how do you get them on a shaft more or less, and how do you mount them
Live axle or dead axle?
It looks designed for a dead-axle drive, so we’ll go with that. You’d put the sprocket onto the hub, and then you’ll need a pair of appropriately sized bearings inserted into the center. Put an axle through the bearings and add to the robot.
it says that bearing come with it, but we will see.