Your drive roller is spinning on takeoff because of the motor is run at excessively high RPM, suggest 2/3 – ¾ of full throttle or you are depressing the foot pedal too quickly, (it’s like dropping the clutch pedal on a car and smoking up the tyres) depress the pedal gently in the direction that you want to go, get moving at least 24” (600mm) than depress the pedal to increase roller speed, be patient.