Analysis of causes and solutions for a detached roof rack

One of my customer bought the roof rack from me and told me that the roof rack came off his roof, taking the kayak onto the road and causing some light damage to both my roof and the kayak, He shouwn me the photo what is happen

From the photo we can find the back one roof rack is detached, as we car drive quickly, the wind will push the kayak head down, Due to the torque, the retracting force of the roof rack at the back will be amplified, far exceeding the specified 75kg., So the back roof rack will detach, It is actually not recommended to place long objects on the roof of the car. It is difficult to estimate the force generated by the wind during driving, and it is easy to lose control. If this is really necessary, it is best to use ropes to fix the front and rear ends of the Kayak to the car. so that the Roof rack only bears downward pressure but not torque.