Your rover's drive train is the part that transfers power from its motors to the ground to move forward and backward.  You must decide whether to use wheels, tracks, or legs, how much ground clearance you will need, and what gear ratio will provide the best balance of speed versus power.

• Wheels
• How many wheels are best?  Each additional wheel adds weight, but also adds more stability.
• Will you power all of the wheels (like a four wheel drive SUV) or only some of them.  Powering all of the wheels adds maneuverability, but also adds complexity and weight because you need to use additional gears, rubber bands, or chains to get power to each wheel.
  
• 4 wheels 
• 6 wheel swamp buggy
  
• 6 wheel Mars Expedition Rover 
  


• Half track 
  
• Is a half-track better than using only tracks or wheels, or is it a compromise that is just more complex and heavier?


• Tracks
• Tank 
• Bulldozer   Notice that the gear that powers the track is up above the other wheels.  This provides better ground clearance.


• Legs
• 


• Ground clearance


• Gear ratio
• Power
• Speed
• Handling
  

• How many motors power the drive train?