J-rack help: What am I doing wrong?

[AaronEcy]

tl;dr: I’m transporting two tandem kayaks using J-racks on my Subaru Crosstrek and one of them—a Hurricane Skimmer 140T that’s 33" wide—keeps moving while driving, though it’s well-secured with cam straps and bow/stern lines. Twice the J-racks themselves have moved; other times it seems to be shifting on the racks. Photo below.

My wife and I recently purchased two tandem kayaks along with Thule Evo Wingbars and Rhino-Rack folding J-racks to transport them on our Subaru Crosstrek. We went with J-racks because the kayaks are so wide, it seemed like the best way to transport both at the same time. She made the four-hour drive to Portland—the nearest city with what we were looking for—and had the rack store install the racks and the kayak store show her how to tie down the kayaks (though they didn’t use a bow or stern line). They made it home fine, but she had to stop and tighten one of the J-racks when she noticed one of the kayaks had shifted. When she got home, she noticed that the bottom plate of that J-rack was bent more than the others and both bolts were bent as well.

Since then, we’ve taken one or both kayaks out several times and had a few nerve-racking experiences. We’re always using bow and stern lines with hood/trunk anchors, with cam straps for all four straps on each kayak. It hasn’t been particularly windy—maybe 10–15 mph—though we live in a windy area. Where we’re going, we have to drive on a 70 mph Interstate, though we’re sticking to around 60 mph. Several times, we’ve noticed the bow of one of the kayaks—it’s always the same one, a Hurricane Skimmer 140T—has shifted several inches to the side while driving. Once, another one of the J-racks had shifted, though we had made certain it was cranked down tight. Other times, it seems the kayak has just moved within the rack, though not by much, as the cam straps on the body, bow, and stern were all still tight. We’ve tried setting the angle of the J-rack to 2, 3, and 4 (guessing these correspond to 20°, 30°, and 40° off the vertical, but I’m not sure), and the problems haven’t gone away.

The other night when returning from the river with just one kayak, we noticed it move to the side while driving. It still seemed secure, so I drove home at 50 mph with the flashers on. Upon inspection, I realized it had shifted in the rear J-rack—I had placed the angular side of the kayak so it fit flush in the angled J-rack, but it shifted inward, dragging the foam padding on the rack down and ripping it (photo below).

Can you help me figure out what I’m doing wrong? Am I not tying it down tightly enough? I don’t think so, since I’m cranking on the cam straps until just before the hull seems to give a little. Any further and I’m scared of damaging it. Should I really not be transporting a boat with such a flat bottom on J-racks—can it just not handle the wind/turbulence? Am I just over-reacting? Watching the bow suddenly slide several inches over while going 60 mph is terrifying, though.

Figuring out what’s going wrong is pretty urgent—I’m a grad student and I’m using this kayak for my research, which is time-sensitive over the next few weeks. The other kayak, which we’re not having problems with but have only transported a couple times, is for taking the kids to have fun. It’s a sit-in, so it doesn’t work for my research, which requires me to jump out of the boat and climb back in in 2–3 feet of water.

Thanks for any advice you’re able to offer! Here a photo of the problem. Not sure if the system will let me post more photos later in the thread.

Rear J-rack where the boat shifted, pulling the foam padding down and ripping it:

[AaronEcy]

The system only lets me upload one photo at a time as a new user, so I’ll try to see if I can add a couple more to help explain.

View from the rear of the car so you can see where the boat shifted from—it had been in the padded crook of the rack:

[AaronEcy]

View from the front of the car

[AaronEcy]

Car with empty racks—could the crossbars be too close together? They’re as far apart as Thule says they should be, but I gather that’s a minimum.

[AaronEcy]

Bent J-rack plate—you can see how the bolts are bent. It still tightens down well, but it’s difficult to remove/re-install. Not sure if this is the fault of the original installers or just something that happened during the first transport. Maybe Rhino-racks aren’t best on this type of crossbar?

Thanks again for any advice. Let me know if any other photos would be helpful.

[Wolf]

I don’t use J-cradles, but most I’ve seen appear to have a deeper “cradle” than the Rhino racks in your photos. That would help keep the kayak from rotating in the cradle, as your Hurricane Skimmer 140T seems to be doing. You could probably improve the situation by routing the cam straps a certain way or using additional straps, but I’m hesitant to suggest anything specific because to me the whole arrangement just doesn’t look very stable and sturdy.

Here are photos of a Rhino Rack cradle and a Thule for comparison:

[rnsparky]

The boat may be too big for the rack or not making sufficient contact. To help the rack from shifting on on cross bar wrap the cross bar in duct tape and reattach the j bar. Grab and shake and twist and push And pull from the side the boat hard while on the rack. If it moves you have a problem

[Celia]

I am not loving the boat fit on that Jrack to start with. But I also see the likely source of your problem.

I am not seeing the boat strapped so that the lower side is held hard against the upright portion of the J. There is obvious space for the boat to shift and take advantage of a few inches between the hull and the upright part, and put a boat in wind you can count on it doing so.

I am not there, but I suggest you find a way to get at least one strap in each location set so it goes around the hull and back thru the upright portion. May need to get a few longer straps.

Then add a second strap at each point - now you will be using a total of eight for two boats - that works more like the ones I am seeing, anchoring the boat to the cross bar to take some of the strain off the Jrack portions. My husband and I always double strapped for longer trips even using stackers, something the guy who sold us out first sea kayaks recommended. My boats have never, ever budged.

[hikenmike]

I always strap my boat through the top and bottom of the “J” as opposed to around the cross bar. I think the strap contours to the boat better that way. FWIW

[Chaoticzen]

I am no aerodynamic expert but if the kayak is shifting during transport on the rear rack with such a force that it bent/shifted the rack, and it’s such a wide/long kayak that’s strapped almost vertically (as all the j racks do). May I suggest two things :

1. You may want to further tighten/enforce that clamp on the j rack instead of using those finger tighten knobs. I would put in another nut with a locking washer to prevent the knobs from loosening

2. How are you doing your bow/stern tie-down? Can you please share a picture or two? You may need to use two tie downs on each end and do an upsidedown V to make sure the kayak isn’t being push on the ends, which creates much greater force then loosen it from the straps.

I guess is the bow/stern tie down maybe more of a factor than the J rack and the long wide kayak on its side really amplifies the wind effect.

Good luck and be safe

[szihn]

My wife has them on her Toyota. But we ALWAYS make a bow-line and tie off to the front bumper and a stern line to tie off to the back bumper.
Needed?
We can’t say because with the tie offs front and rear we have had no slipping at all. Maybe we would never need the bow and stern lines.

Is your seat belt needed? Not yet. They are never needed --------- until they are.
Like guns, fire extinguishers, a health insurance policy or even just locks on your doors, when you need them it’s too late to go buy them. They are worthless if they are not already in place.

3/8 inch rope is very inexpensive and it’s fast and easy to tie off.

[Celia]

The OPer said in his original post that they used bow and stern lines. That is not an issue.

The photos show the slippage that did take place with bow and stern lines in place.

The details of how the straps and lines are run is the only place to go here as long as they stay with the J’s.

[bud16415]

Here is my opinion on your problem.

First off I would not use it at all with bent clamping bolts and a bent bottom strap clamp. If it came that way from the installer I would not have accepted it.

Second boats come in all kind of shapes and sizes and weights and the Js need to be set so they work with the straps so during vibration things can’t loosen up. That requires trial and error.

I like how you bring the straps below the crossbars as if the Js came lose everything would stay somewhat attached.

[rnsparky]

Single line Bow and stern lines are for movement along the length if the boat for hard stops. To stop side movement from cross wind you need the lines to form a V with two separate lines at each end.

[rnsparky]

Here’s the best solution. — Since you have raised roof rails get Yakima or Thule rail grabber clamps and 78 inch cross bars which would fit both boats hull up on the bars. Been doing this for 25 years with no problems with canoes, and 9 to 15 ft kayaks, long trips at highway speeds. You just confirmed why there are so many j bars for sale on FB and craigslistt

[willowleaf]

Honestly, just my opinion and personal paranoia but I would not use J-racks to haul such bulky boats. I have owned Thule j-racks for 16 years and have hauled all manner of kayaks up to 18’ and 65 pounds on a range of rack set ups for thousands of highway miles. I am very uncomfortable with the obvious wind and inertial forces that apply to boats carried in that position. In fact if I aprroach a vehicle on the highway carrying boats on them that clearly have the sort of poor contact yours show I back off following them or engineer a pass to avoid them.

I have seen too often how boats can torque and shift in these things — horrible aerodynamics fir one thing. And few boats fit snugly into the angle the brackets create, especially wide and deep rec style hulls and SOTs. I completely mistrust the fold down models and any brand other than Thuke or Yakima. My own brother buikt his own j’s from pvc counduit, wood, and u-bolts to haul a heavy 17’ Looksha I gave him and I have been fighting with him about using this jerry built contraption ever since. IMHO the only truly safe and best aerodynamic way to carry a pair of boats like yours would be to get a Thule rack with cross bars long enough to allow them to be carried side by side and preferably inverted. Possibly with a pair of stackers between them for even better lateral stability and ease of positioning in loading.

Others may disagree but I state this as soneone with a lot of experience with multiple boats (and other long heavt loads), vehicles and rack systems (starting with Quick’n’Easy gutter clamps and home made pressure treated wood racks on a 1970’s station wagons.). I have stopped using my j-racks out of concern for the drawbacks I see to their mechanical durability and the issues with getting most boat hulls well seated in them.

[JCH_ski]

I have a couple of sets of Malone J-racks, and one set came with brackets formed the way yours are- I’m not sure yours are bent entirely from use. All or a lot of that may be shaping to fit around certain types of bars (round or square). However, those bolts MUST be replaced! They have yielded, and are no longer able to do their job. Take them apart and go to the hardware store with the bolt and the nut, to make sure you get the right size and thread. Get at least grade 5 bolts to replace them - grade 8 wouldn’t hurt. They are likely carriage bolts.

I defer to the more experienced users here on the rest. It is very possible (likely) that the boat is just too wide, and the lower leg angle of the carriers is just too shallow. Another option would be saddle carriers for this boat, if the problem only occurs with that one. One question: have you tried loading the boat the other way - hull outboard? I don’t know if that would help or hurt.

I have a Crosstrek as well, and have never had the slightest hint of j-racks or saddles moving, or boats moving on them. 29” is the widest we have carried. I did notice that in the photo of the car with just the racks, the racks are not sitting parallel to each other. I’m not sure how much difference this makes, or how far one would have to move to align them, but the boat probably isn’t contacting both carriers correctly. You’d think car manufacturers would design these things to be flat. I suppose this is more aerodynamic.

[JCH_ski]

PVC!?!? That is a disaster waiting to happen. Seriously. I’m speaking as a retired mechanical engineer. If his Js are made of that, they cannot resist any load, and they WILL fail. So keep fighting him on that!

[willowleaf]

JCH-ski: Fortunately, the SUV that rack abortion he built was mounted on kicked the bucket a couple of years ago and now he drives a pickup truck (I still fight with him over his just propping the 14’ kayak – another I gave him – in the bed to haul it with little in the way of tethering.) I fear what he would attempt with the Looksha 17. But I noted he kept his home made j-racks in the garage and fear he will mount it on his wife’s next car. My “little” brother gets very wounded when I criticize his contraptions. But next time I visit him I may try to find those in the garage and neutralize them for good with a hacksaw. Rather have him pissed at me than kill somebody.

I was a factory sales rep for Carlon (major PVC conduit and fittings maker) for a while and also installed (and hot bent) a lot of it as an industrial construction electrician. I am extremely aware of it’s structural characteristics and vulnerability to UV aging. Had no idea he was planning that project until he sent me pics of that battleship Looksha perched on his new contraptions and my blood ran cold. I’d send you those photos but they creeped me out so much I deleted them from my phone. At least I convinced him he HAD to run the cam straps around the actual factory roof rack and not just through his Rube Goldberg j-rack as he had in his original mounting (shudder.) So at least had it all failed on the highway the unfortunates following behind him would only have to deal with shattered PVC and scraps of deck wood hitting their windshields and not a 17’ rotomold projectile.

[AaronEcy]

Wow, thanks so much for the help, everyone!

I have this sinking feeling that what several of you have said is correct—J-racks are really not the best solution for transporting such a wide boat. This matches my experience, as I can really feel the lateral forces when I’m driving, even when the kayak isn’t shifting around. Every time we’ve loaded the kayaks I’ve grabbed them and tried to push/pull and shift it left/right, HARD. The one never budged, until driving.

For now, I’m thinking my best solution might be to transport the other kayak—a Perception Cove 14.5 T that’s 31.25" wide—in one set of J-racks while strapping the Hurricane deck-down next to it. So far, we haven’t had trouble transporting the Perception in the J-racks and the bars aren’t wide enough to place the kayaks side-by-side, so I don’t think I have other options until I can find wider bars.

I’ll also try some of your suggestions—tying the Perception tighter to the upright part of the J-rack so it stays flush, using inverted Vs for the bow/stern straps.

Let me know if you have suggestions for securing the Hurricane upside-down. I’m off to research how to do so safely/securely.