Obviously you should tie a large flat object like a Laser to more than just the racks themselves. You refer to the pullout strength of the factory racks, I was referring to the strength of the roof itself where the racks are attached, which is what I think the weight capacity means. The factory racks are often attached to the roof a short distance inside the edge of the roof. This means that they rely on the strength of the roof itself to support the weight. Aftermarket racks that attach directly to the car (and not to the existing racks) usually attach to the rain gutters or to a dedicated attachment point. The weight applied to aftermarket racks is carried by the sides of the car itself, which is why aftermarket racks have higher weight capacities.