[longrange]

We anticipated a problem like this and changed the sprockets initially. We went with 11 and 32 from McMaster Carr and received them in 2 days. We discovered that putting two 11 tooth gears side by side we had to turn down half of the hub of one sprocket for the chain to clear the hub. Also we had a problem with the alignment of the cim motors as mentioned earlier. We ran the robot elevated and tested each motor in forward and reverse using a power supply to measure the current. After making slight position adjustments to the motors, no motor draws more than 5 amps @12.5 volts.
Also if you adjust your chain tensioners tooooooo tight you will load the system down.