Over-loading the roof

@davavd
As I mentioned above somewhere, it may be extremely challenging to find a weight limit for the side rails, and the sales people tend to be equally useless. Few car manufacturers think about the needs of people who put kayaks on the roof, and even those who do make strange decisions. Like the “redesigned” racks on the 2010 Subaru Outback, which interestingly you can avoid now by getting a Euro package. All they have to do is go back the same rails the Forester has and they had on the Subaru before 2010, but I guess that is too easy.

Anyway - that rant over - one above post has it right. The frame that those side rails are over is intended to provide a degree of safety in a rollover. There is no way putting racks and couple of boats over that point is going to challenge its limits unless there are concerns about how the side rails themselves are anchored. Given the effort it takes to get the darned thing out, most of these are awfully solid for the purposes of carrying kayaks.

One note on the side wind issue - we noticed pretty quickly that the ride went more smoothly once we got neoprene cockpit covers for our boats

One comment. The roof is made to handle a roll over of course. BUT that has nothing to do to rack capacity. If a rack fails it gets pulled off upwardly. Like my rack is clamped on so if the clamps fail they will get pulled off by wind pulling upward on the boats. Same thing for the suv factory rails. If they fail they will be torn off upwardly not by down force of weight. Its about how much force those factory rails or after market clamps can take from wind pulling up and sideways. At least thats how I see it.

@dc9mm

I have probably seen as many poorly mounted rack and boats setups going sideways as upwards on the highway. But this is all an argument for at least bow lines. Those who have an engineering degree can argue about whether stern lines provide protection against the same kind of forces or are doing something else. The other thing that I have done since I tried to carry a canoe on occasion is cross the bow lines so right pulls left and left pulls right. Not sure it is doing as much for the kayaks as a canoe, but it does hold pressure against the inside which is usually the highest part when using a stacker or the Hullivators.

Sounds like the above is talking about towers mounted directly into the channel. That goes to a comment higher up, that there are times when it may be prudent to replace the towers in a rack system even if everything else seems solid. Those feet take a lot of the workload.

Becareful because you can damage your roof from an overload even though roof is made not to collapse from weight of vehicle. My yak towers are on factory racks. I know if I go past 100 lb limit I can damage sheet metal on roof. Even the 100 lb rating is scary for me.

@Gsetc
Unclear what you are talking about. If you have third party cross bars, which are generally rated for near 200 pounds for each bar, on side rails which are rated for a couple of hundred pounds, and everything is secured properly - hard to figure out how going to say 150 pounds for a couple of boats is going to impact your roof. Unless you are talking about using the factory cross bars and there is a misnomer somewhere.

my OEM roof rack with 4 Yakima Towers attached to OEM roof rails with Yakima bars is rated for 100 lb. total minus weight of two bars and 4 towers. Put my Libra XT up there at 95 lb. empty and that’s it sadly.

@davavd said:
Tell me some stories about how much you piled on your roof racks.

I have a Canyoh P/U truck with Thule square bars and towers that mount solidly near the edge of the roof. I went with longer bars, as a lot of people who haul boats do to maximize their roof space. I planned it so that I’d be able to carry a canoe in the middle and a kayak on each side in a J-Cradle. I’m pretty sure this does exceed the weight limit of the system but have yet to actually have this configuration of boats on the roof.

I have enough space that I can carry four kayaks of any length in J-cradles, with two of those cradles mounted outboard of the towers. I’m sure this also exceeds the weight limit. Again, I have yet to actually have four boats on there, but there’s room to do it.

The most I’ve actually put up there is three, and I’ve done so with three full sized sea kayaks on quite a few occasions. I’ve done it with one J-cradle in the middle, and with simple foam blocks directly on the rails. I suspect this probably exceeds the weight limit too. I’ve driven over 10 hours round trip with them up there and no problems then or now. The biggest problem I found was fuel consumption was considerably higher. Aside from that, even in a crew cab pickup truck 3 people plus camping gear is getting pretty cramped. Four might work, but not with the stupid amounts of gear I’ve seem most people bring along with them.

Picture from spring 2015:

@Kayak_Ken said:
While weight on the racks is important, I think how you drive should be considered also. Hurricane force winds start at 70 mph. Something to think about when you are driving down the highway at 70+ mph weaving throught traffic, being hit with cross winds from weather or semi’s.
When I use roof racks, each boat has it’s own set of straps and front/rear tie downs. When given a choice I always go with my trailer even if I am only hauling one boat.

Have to agree - it is not the weight on the roof that is the issue, it’s the force on the boats as you are traveling down the highway. I think it is much for likely that the rails get ripped off your car than that the roof gets crushed from the weight of the boats. Even that is pretty unlikely with two boats as long as you tie them down. The trouble with a Rav4 (and my Forester, or any other SUV) is that it is tough to get a good tie down line on the stern.

Packed and ready for vacation.

A 4-door sedan is much better for that.

IMGP1318

@eckilson said:

The trouble with a Rav4 (and my Forester, or any other SUV) is that it is tough to get a good tie down line on the stern.

That’s not true, especially with canoes. There’s no reason that you can’t attach your rear tie-downs to a thwart instead of to the extreme back end of the boat. Related to this, I position my boats slightly behind center on the rack itself (not centered over the entire car as your pictures show). Then, tie-downs from the bow to the front of the car pull the boat in somewhat of a forward direction, and tie-downs attaching the thwart behind the seat to the rear of the car pull down in a slightly rearward direction. Thus, front and rear tie-downs oppose each other and the boat won’t be able to move all that far in any direction if the rack were to fail, and the rear tie-downs are a lot more effective in fighting normal buffeting forces as you drive than would otherwise be the case.

This photo shows rear tie-downs on both a kayak and a canoe, but I didn’t bother to use the described method on the kayak (it can still be done, with a lasso around the coaming, but I seldom do).

http://tinyurl.com/lpraynk

Also, putting the boat slightly rear of center on the rack itself helps immensely in cutting down how much buffeting occurs due to crosswinds and semi-truck turbulence, which also reduces strain on the whole rack. Doing the opposite, especially when done to the extreme (as in your sedan picture) magnifies that problem, so positioning the boat so it’s practical to use a thwart for your rear tie-down kills two birds with one stone.

Not sure what Eckilson is referring to on the stern tie down. It may be whether there is a good rear option similar to the eyelets available in the front bumper on Rav4’s and Foresters. In the rear, there is an option for a hook-up but it is not designed to be easy to reach for the end of a long day on the water. It is some kind of special purpose thing that is much less clear in its intention. My old Outback, pre-2010 redesign, also had that situation. The rear was just not set up to be as user-friendly as the eyelets in front. It was puzzling.

As to the direction of how the straps or ropes run, if I am carrying a canoe I try to line it up so that the thwart which is most rearward lies near enough to the cross bar that I can attach the thwart to that cross bar. I use a long strap or rope which has enough left over to do other things with it, from there you can secure to the back of the car or run it out to the stern to be hold a driving flag.

But in a car with a pretty hefty rear stupid plastic projection, which the Rav4 has, you have to get the whole thing shifted far enough back that the rope from the thwart is not putting pressure on it. That can be harder to avoid depending on the specifics of the setup.

I tend to only take the canoe out very locally, so in my case the extra length gets used for the driving flag. I haven’t tried it since getting the Hullivators though, I suspect it won’t fit with the Hullivators up.

This is turning out to be a very informative thread. Thanks again to everyone. I will add one piece of information I don’t think I have seen much discussion of. I try hard to get my two (yes, two) forward ropes on each boat to pull opposite from my two rear ropes. On the Rav4, this means using the top front door hinges as the forward anchor point. I use a piece of 1" webbing, passed around the hinge, with grommets in each end. I put a loop of rope through the grommets to make it easier to attach more than one rope (if I’m carrying two boats). At the back of the car, I have the same kind of arrangement using the tie-down loops just inside the rear hatch. My front ropes pull back and my rear ropes pull forward. With two ropes at the end of each boat plus two belly straps, nothing moves much. Usually I do this with two really light solos. I started this thread because for this trip, the boats are heavier (though still light) tandems.

@Guideboatguy said:
There’s no reason that you can’t attach your rear tie-downs to a thwart instead of to the extreme back end of the boat.

If there is an attachment point (there really isn’t an easy connection point on my Forester), I understand that you can attach to the thwart rather than the stern, but I don’t think that is as effective at stabilizing the boat as on a sedan where you can get two lines in opposite directions at the end of the boat.

@Guideboatguy said:
Related to this, I position my boats slightly behind center on the rack itself (not centered over the entire car as your pictures show).

You and I have debated the placement of boats on the car before. When I can, I do center the boat on the car as recommended in this old Mohawk video (go to 0:38).

https://vimeo.com/123483662

It works great on a sedan when you can get two lines in opposite directions at each end of the boat. Even on my Forester I place the boat slightly forward since it can be stabilized by the bow lines - never had a problem with turbulence or crosswinds, but to each his own.