I'm making a rc cart with 4 wheels with rubber tracks on them. Two front wheels are powered by two dc motors 3.5-15[Nm] torque. Torque of 15[Nm] represent stalled torque. Let's say that friction between wheel axel and body of cart is minimal. Diamter of axle is 10[mm] and the diameter of wheel is 100[mm]. Motor spins at 35-70[rpm] depending on two posible gears (it's a windscreen wiper motor). What is maximum load it can carry? I found some calulations that are totaly different. One of them says it can carry 230kg unlike the other says only 15kg. I guess calculation of 15kg would be maximum lifting force instead of pulling but I'll let you decide what is correct. Thank you very much!