I was curios about the weight limit on factory racks. I drive an 02 santa fe and it has sticker saying 75 lbs evenly distributed. Well this weekend my entire fleet must hit the road. I can get one canoe and two kayaks on my trailer but that leaves the 80+lb. old town canoe to go on top of car. I figure Im within the safety factor for the factory racks but once considering the extra force from straps and bow and stern lines I might over load.
Your thoughts?
Well, My Trust Ended In the Late '90’s
– Last Updated: Aug-09-13 2:08 PM EST –
Had a '97 RAV4 and mine broke with canoe on top. Since it was well tied, it put a nice dent in the roof. Had I been on the interstate, it could have been ugly. I bought a Thule rack then and there. I've used both Thule and Yakima and have been happy with them. As I paddle most weeks of the year and use my racks all the time, it's worth the peace of mind to me.
I have never trusted factory racks and .
never will.
Jack L
unusually low weight limit
75lbs is pretty wimpy even by factory rack standards.
If it were me, I’d load the boat, strap it down, and give it a good test by pulling and pushing real hard on the tie-down straps. If the rack looks solid, then maybe you’re ok. If the bars flex a lot and look questionable I’d invest in a good aftermarket rack. Use your best judgement.
You might go to 100, but don’t tie your
end ropes down too hard.
It really comes down to one’s own judgement and instinct about materials and loads. The stated limits by car makers seem to have been written by lawyers. I feel I can judge what load a set of rails, topped by some sort of crossbars, can handle. I don’t feel the car maker, Yakima, or Thule limits are based on real experience, but I would not want to go way beyond them.
How air loads work
Aerodynamic loads increase by the square of the speed.
In other words, if you double the speed (say from 30mph to 60mph), then you quadruple the air loads. If you triple the speed (30 to 90 - don’t forget about headwinds), you increase the air loads by NINE.
I can’t tell you what direction the air loads will be in - that depends on your car, your canoe and the weather and the semi-truck that is buffeting you.
That rack is not up to snuff in my opinion.
If you use it, tie the canoe so that it stays put with a failed rack - tie it at the bow for sure, maybe the stern, and pass an extra strap over the canoe AND through the passenger compartment.
True
– Last Updated: Aug-09-13 5:58 PM EST –
The speed-squared increase is correct, but maybe isn't too serious if the aero load is only 3 pounds at 30 mph. Hard to estimate, of course. I agree with the view above that there is probably little actual testing behind published load limits.
I once did an estimate to see how fast one would have to drive to have the same drag on the kayak as it has at 3 knots in the water. My answer was around 60 mph (based on similarity arguments), which indicates that aero drag on the boat is about 5 pounds or so at that speed. There'll be more from the rack, maybe doubling the result. Again, this load is straight back, and will create an overall torque on the rack system base on how high the load is. But it isn't the same effect as the dead load of the boats. Buffeting by trucks is another issue, and it's hard to say how that is (or likely isn't) taken into account.
I agree that 75 pounds seems very wimpy - the aero crossbars on my Mini are rated at 75 kg, about 165 pounds, I think they're made by Thule.
Thanks
Thanks for insights. In 7 years I’ve had this car I’ve never had reason to place this canoe on roof. I have always trailered it. Who wants to lift 80 lbs that high anyway. I may remove cross bars and get some of those foam blocks and place directly on roof. Either way i will likely take the the state routes and not interstate. Double nickel all the way.
Derek
True
everything is fine and dandy as long as everything goes as planned.
Yaw that canoe 20 degrees at 75 mph and the airloads aren’t going to be 9 lbs. Things go bad fast if something comes loose. F = MA…since the Mass doesn’t change, the acceleration goes up just like the air loads. If it goes, it’s gonna go fast.
FYI - I tie my canoe to the rack (its a good rack) only when I drive across town at 30 mph, but the bow lines go on before I ever get on the highway.
Well, that’s my piece. I got stuff to do.
Agreed
definitely agree that things can go south quickly if the boat goes askew. Same goes for oscillation due to buffeting by trucks or crosswinds. I’m spoiled by a rack system that prevents almost all of this, so don’t have to worry about it too much.
Santa Fe rack
I hauled boats on Thule crossbars attached to the factory rack on an '03 Santa Fe for two years, including for one short trip both a 75 lb plastic canoe plus a 46 lb kayak. If you include the add on rack components that was pushing 150 lbs. I regularly hauled the 46 lb boat plus a 62 lb boat together on that car, even at highway speed. No signs of stress on the factory rack. I tend to think the racks are rated far lower than they will actually withstand. I always use stout bow and stern lines to the bumpers plus heavy Thule nylon straps, wrapped around both the add on and factory rack.
I just drove 500 miles this week at highway speeds with 84 lbs of kayak (plus 15 lbs of Thule cross bars and J racks) mounted on my '02 Subaru outback which I also think has a 75 lb rack rating. I would not fret at loads up to around 125 lbs, pushing 150 makes me a little nervous.
gotta go w/G2d here
use the limit and discretion as a guide.
I had a subaru that could carry three kayaks, I believe the limit was 150#. In addition, the rails were stout and were connected at three points along the car’s roof frame, not just two.
My next car was an SUV with a roof rack system attached to the roof sheet metal with what looked like sheet metal screws. So, that came off and I put a Yakima system on.
What you could do …
– Last Updated: Aug-10-13 4:00 PM EST –
... Is take a page off the poor man's book on car racks for this trip only: strap a pair of nice 2x4 or similar pieces of wood on your factory rails, thus bypassing the factory cross bars. That is, if your Fe has rails and not some fancy-shmancy built-in rail-like protrusions... If the rails are sturdy and you do a nice tie down job, this works surprisingly well.
No Problems today
Today loaded the canoe on the factory rack. Used 4 heavy duty ratchet straps to secure the boat to the car. Took special care not to put much downward force on the racks but still be secure. Kept speed down to under 60mph on the two hour drive each way.
The rails were actually close enough that the canoe didn’t rest on the cross bars, but on directly on the rails.
Have a good day
Derek
Never use ratchet straps !
You can damage your canoe or worse, your rack system.
Use camlock buckle straps.
Jack L
Or better yet -
use 1/4 or 3/8 inch rope and trucker’s hitches. Less chance of failure imho. You do have to know how to tie the knots properly.
Factory racks or…?
I’m confused whether your talking about the racks that are bolted into the car roof, or the bars that you actually place the kayak on. I replaced the bars that the kayaks rest on, but the factory racks seem rock solid and are bolted in at 6 points to the roof so I can’t imagine them causing a problem.
Lyn
good question, and a recommendation
regardless, if one has enough confidence in using factory rails, whether or not one uses bow and stern lines, one really ought to tie off onto the rail in addition to the crossbars.