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: