Need a roof rack CSI

So, don’t know how many of you have had the thrill of a kayak rocketing off your roof rack at 70 mph, but this weekend it happened to me, and I am trying to figure out what went wrong. It was a large sit on top (Ocean Kayak Prowler 15) fixed on a set of yakima bow downs (a kind of modified J cradle…would recommend not buying these now). I had this setup in place for a couple of weeks and never had a problem and then all of a sudden while traveling on the highway a gust of wind (though far from hurricane force or even the worst wind this setup had been used in) followed by a large cracking sound and suddenly my kayak was airborne on the louisiana highway. Upon examination of the remains along the side of the highway I found that the vices that secure the “Bow Downs” to the roof rack had both snapped, and the eyelits that my bow and stern lines were secured to had also snapped (and I mean the eyelits themselves, not that they had pulled the rivets out). This was my first sit on top and I am thinking that perhaps j cradle style racks are not the best for this type of kayak. I have two theories, one is that the yakima bow down is merely a shoddy piece of equipment, as the vices that secure it to the cross bars are made of weak (and obviously breakable) plastic rather than steel. The other theory is that perhaps the one the side position of the kayak while traveling caused excess strain to be put on the bow downs, causing the break. The kayak (kudos to Ocean Kayak) is undamaged, but I am suspending sit on top use until I figure out a better roof rack setup. Does anyone have any theories as to what went wrong and what could constitute a better setup for transporting a big heavy sit on top, as I have never had this problem before with regular kayaks.


I have used Yakima boat cradles of
various kinds since 1990, plus other kinds of Yakima devices, such as kayak towers. I have never had one of the plastic clamps break or crack.

Given your description, I suspect that some unusual force ripped your boat loose. But we’ll have to wait and see whether others have had plastic clamps break.

where is the speed limit 70?
You could slow down. People do that when it’s foggy or icy. Trucks to it with a heavy load. Stay within what the conditions will permit.

I don’t know the anatomy of the Ocean Prowler 15, but you could tie off your line around other points. Was it the toggles that popped off? If not, you could run some line through that. And use line, don’t trust those goofy tension systems. Get some rope and use knots. A bowline & truckers hitch should do.

Good luck!

not the best combination
Sit On Tops in any kind of J-cradle are really hard on roof rack components. They present such a large surface area to wind which really torques the rack. I’m a big proponent of not just running bow and stern lines, but lassoing them around the boat so the strain is on the boat, not on the fitting for reasons you found out.

I too, am not a fan of the Bow Downs on Yakima racks. Their universal attachment method works much better for factory racks but regardless of how tight they are, will still twist on the crossbars. The will twist in the X-axis like all Yakima Products will, but also in the Z-axis which I find unacceptable. But Yakima’s components rarely fail. Do you often travel without bow and stern lines? You said that the rack has been in more severe winds. I would tend to believe that the rack had taken severe stress loading over it’s life, albeit short, and this was the trip where it broke.

Contact your dealer and have them start the warranty process with Yakima. They’ll ask a few more questions to find out info you have not supplied. Like what is the make model and year of your car. What are the specifics pieces of base rack do you have installed. The conditions you were in and so on. They’ll want photos too. Yakima carries insurance for this purpose. If you were within load limits, carrying a properly secured load, and following all of Yakima’s guidelines, then they’ll take care of you.

But for your next rack, I would try to carry the boat flat instead of on its side.

actually if you think about it, hurricane-force winds start at 73 mph, so any small amount of headwind plus the wind resistance generated by your velocity of 70 mph, qualifies as hurricane force… so your rigging needs to be up to that task.

you didn’t describe how your straps were set up? if you tie the kayak only to the bowdowns, and are relying on the bowdown brackets to hold onto the rack, I can see how that will fail under high stress. the straps need to secure the boat to the load bars of the roof rack and not just the cradles.

There are long stretches of 70 mph
speed limit in many states, coast to coast. If the poor guy was doing only 70, he was being alot more law-abiding that most.

I will admit to having briefly hit 110 mph with a decked boat in Yakima cradles.

I think the victim in this case was hit with a freak localized wind shear that he didn’t much feel inside his vehicle, but which put very unusual stress on the boat and clamps.

Don’t know about Bow Downs but I always run my tie down straps to include the cross bars and side rails when possible. It would take ripping the complete rack out of the roof to loose the boat. I would never trust a single mounting point.

bow downs
Yeah, I think you are right. I never have failed to use bow and stern lines, but I think the upright Sit on top simply pulls too much wind resistance for the largely plastic J-Cradles. I guess I’ll go back to mako saddles, unless there is a better sit on top option.

might want to see what the bow downs are
rated for speedwise…sometimes manufacturers put a upper speed limit since they do not want this happenind…those sofr foam roof racks you strap on-do not go above 50 with them…the manufacturer will not even touch you if you speed and something happens…

a 30" wide sot on the roof just gave your vehicle a BIG SAIL!!!

a friend lost his waveski on route 93 in boston once for the same reason…blew the ski right off…that got run over!!!eewwwwww…

but Luke’s issue was even worse-the gust of wind hit his truck hard enough that the wind bent the thule bars DOWN! about 9" just past the attachment point on the roof…thule did cover this one…

personally i only use any sort of vertical kayak rack if i am carrying a bunch of boats…other wise they all go hull down…and i go 85…

I only have Thule J cradles for my Emotion SOT kayaks (one single, one tandem and one fishing). I did notice that the straps that came with the Thule package were not long enough to cover the bow and stern making me think that I really should not be using them for my three SOT kayaks. I just used larger straps and I have been fine even traveling over 70 MPH but I still wonder if I am testing my luck. Using the J cradles allows me to carry three on the van roof though.

Pretty sure all rack systems tell you to do this.

If the whole rack rips off - its a car or rack mechanical failure (or a really low bridge!). If straps shear/snap - they weren’t twisted over open spans to dampen vibrations - and/or were old and UV degraded. If kayaks fly off with mounts still attached and straps intact - it’s a user’s failure to secure all to the rack.

Thank you for posting
I probably speak for many when I say this caused me to take a closer look at how I tie down my little boat.

The straps that came with my Yakima Mako saddles only strap the boat to the saddles. I’ve trusted those in the front, but in the back I’ve always put a strap around the boat and the cross bars. From now on, I’ll do both in the front.

I never considered that the gizmos holding the saddles to the cross bars could break—and they haven’t, in 6 plus years, but now I’ll add that extra measure of safety. Now nothing can come off unless the entire rack comes off, and it is solidly locked on.

You indicated that eyelets failed - I assume the parts that go around the bars snapped.

One possibility - by tightening too much you can create more tension that the kayak would ever provide acting as a sail.

On the bow/stern lines - one trick is not to use loops attached to kayak for tie down, instead use those loops to stabilize 1’’ webbing which can in turn be attached to the tie downs. I have no idea if this sort of setup is possible with your kayak, but this is what I received with bow/stern tie downs.

Your most likely culprits are the straps. I see this a lot around here where people will only run their straps through the cradle attachment and not the cross bars. (This is also a demonstration of why bow and stern lines are needed) The cradles are just that places to cradle your boat and the straps need to be around the cross bars as well to provide addition support and security. I’ve had three boats on top of the car using various attachments (stackers, J bars, and saddles) at 70mph in storms, cross winds and gusts with out any problems.