I am not sure if you turned on the ESC turbo function. If the turbo is on, it seems the gear ratio has too much torque. Usually we set 5.5 with turbo and 6 for non turbo.
We also suggest you to add molydenum grease on the gears to protect from wear.
We just had a race last weekend with 3 VBC drivers in 13.5T non turbo setup with grease on gears and the gears were totally fine after full day of racing. Please give it a try.