Can confirm that the ESC locks up the rear inside wheel in low-speed turns. I think it has to do with the rear torsion beam - it's really easy to tripod, so the ESC detects wheelspin and stops the wheel. It does not happen to the Tograc or Vivace S. It does happen to the models with independent rear suspension for similar reasons - if you tripod it, the wheel that goes in the air stops spinning. Update: it usually only happens when you make it happen. Floor it up to 20 MPH, release the gas and immediately go to full lock left or right. One of the rear wheels will lift into the air, or there will be so little weight on it as to have the same effect. The ESC will stop the wheel.