I think she is referring to the crossbars not the roof rails. You have two options you can get a Thule tower that attaches to the factory rails and in most cases I think you can still get towers that attach directly to the roof. I think the guy was talking about the actual attachment of her kayak rack with Thule mounts not fitting on the factory cross rails not that you can’t put Thule crossbars on the car. I don’t think you would have a weight issue either, I know people with Thule racks on the factory rails who can put 4 kayaks across on their sides and then two more on their bottoms on top of these and have had no issues.
This is a Subaru Fan post and I don't mean to rain on your parade.
First, the bar spread on a Subaru is 24". The kayak is 17' long. There's a lot of pressure on the ends of the kayak from the wind. If I can get the rack closer to the bulkheads, it is better for the boat not to flex so much.
Here's the problem with roof racks in general. It's not the roof, it's whatever is the weakest link of the system. Your roof is able to withstand a rollover which is considerably more weight/pressure on the roof than a couple of kayaks. The weakness could be in the rails or the crossbars or the connectors that hold the rack to the roof. I don't know what the weakest part of the Subaru is, but I was told by the salesman that it can only hold around 100 pounds.
As you know, a part of the Outback's roof rail rotates to become the crossbars. Maybe the hinge is the weak point, because all of the weight is carried on the hinge and clip??? I don't know.
At the time I looked at a Subaru i 2013, Thule did not sell a connector that held the Thule crossbars to the Subaru rack. So there was no way to connect the longer Thule crossbars required for the Hullivator to the roof. I don't know if you can see from the photo I posted earlier, but the rails stand away from the car about 8 inches, so that when the kayak comes down, it doesn't hit the mirror or the side of the car.
Gloria, when your friends put so much weight on top of the car, it is a danger to everyone on the road. It's not about if the car can hold the weight. It can.
The problem is basic physics. Velocity. Momentum. Inertia. Newton said, "An object either remains at rest or continues to move at a constant velocity, unless acted upon by a force."
The problem is that in the event of an accident, either with a stationary object or an oncoming car, those boats are moving at the same speed as the car. Then, the car stops and the boats keep moving. Newton's Second Law.
It comes down to, what's the weakest part? The straps? The other boats? The crossbar? The screws that hold the roof rack to the steel bar in the roof? The weakest part is going to fail because it is not designed to hold so much weight IN AN ACCIDENT.
And while I have everyone's attention, if your boats are not tied front and back (as well as on the rack) to your vehicle, your load is "not properly secured" and YOU CAN GET A TICKET.
I witnessed an accident that could have been a relatively minor collision. However, the kayaks were not tied properly and flew forward off the top of a car into oncoming traffic on the highway. No one was killed, but the accident caused by the flying kayaks and serious injuries to innocent people could have been prevented if the ignorant &*%^$& with the boats had tied them down properly. Off my soapbox. Sorry. I get carried away.