[EricH]

Originally Posted by caincteam2777

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.