I have to agree with miller tyme. Todays electric motors are not designed for 30min runs even though new battery technology will allow it. It is hard enought to keep motor temps down during a 5 or 8 minute run at an indoor carpet track. I would save yourself the $150 and run for say 10min, take a break, and run again when the motor has cooled. You will also be amazed how much dropping a tooth or two can lower motor temps.
-Kane