How many twists on straps
Post a picture of what your straps look like. As others have mentioned, this is typical of a strap that’s oscillating in the wind. You can add two or three twists, or wrap something else around the strap. If the problem persists, move to rope and it will be less likely to catch wind and oscillate.
Tie up any excess strap ends, or just toss them the end in the open door and shut it.
Yes I do 3-4. Wondered what he did.
Second the crossbar idea. My old truck howled all the time. I tuned it out but passengers would all ask “What’s that sound?!”
If you have not fixed the problem yet, you might post a picture of your set up with the boat tied down. Small changes in the straps and orientation of the boat can cause problems, because you set up a harmonic oscillation at certain speeds.
Noticed the same thing with our canoe - loading it a few inches farther back lessened the sound somewhat. the webbing used to strap it down was all tight on the canoe’s belly - nothing for the wind to grab and excite… With a kayak it might pay to close it off - or it becomes a giant pan flute perhaps under the right circumstance ( windspeed, carspeed, loading orientation )
It is often the strap beween the hill and the bar, the hypotenuse.
On a recent trip I had a loud buzz coming from the front strap and stopped to adjust it about 6 times until I finally swapped the 1.5 inch wide NRS front strap for a normal one inch wide Yakima strap and the noise went away completely. The NRS straps never buzzed on previous vehicles…noises can be really sensitive to details!
@string said:
It is often the strap beween the hill and the bar, the hypotenuse.
Well that explains everything… except the hippopotamus being executed (hippo-to-noose)
Well if it we’re a whoomp! I’d say it was the cockpit cover needed a strap across the cover. But you said a “rumble”.
@Sparky961 said:
@string said:
It is often the strap beween the hill and the bar, the hypotenuse.Well that explains everything… except the hippopotamus being executed (hippo-to-noose)
Blasted spell check. HULL
@string said:
Blasted spell check. HULL
Indeed. Fortunately we “biologicals” are still better at that than computers. Perhaps there will come a day when this is no longer the case.
I never hear any loud, rumbling, or buzzing noises coming from the the canoes I carry, from the NRS tie down straps I use, or my Yakima rack…
But then I typically have a CD by the Allman Bros., Tom Petty, the Eagles, the Tedeschi/Trucks band, Bad Company, or ZZ Top, cranked up to about 9 on the CD player.
B)
BOB
good selections, I wanna run shuttles with you bob!
Is your nickname " what?"
The straps, position of boat, readjusting rack are all good “fixes”…if they don’t work, consider checking your rudder if you have one, and/or foot braces to make sure they are locked in transit so as not to vibrate at higher speeds.
One responder said, “Twist em”. That always worked for me.
Wherever you have a strap in tension that is flat to the wind for a foot or two, that strap can “sing” or “roar” in the wind at highway speed. One full twist per foot of strap that isn’t touching a hard surface should stop that noise. Other things can also “sing” in the wind, like a loose rope end, or even a seat back. If a taught rope is singing, tie another rope or a bungee to it to stop the vibration.
Round rack bars can also generate noise like “moaning”, when nothing is on the bars. Air vibrating around them at highway speed can cause noise. You can take a piece of outdoor carpeting about as long as the bar, maybe 10 inches wide, and wrap or loop it around each bar. Sew, glue or otherwise fasten the carpet to itself (backing side to backing side) on the downwind side of the bar, thus creating an approximate airfoil shape. Cut it away as needed for straps, supports, etc.
Large holes in a flat plate parallel to airflow can also generate “moaning”. I learned about this when I made a roof rack using flat aluminum plates to support the bars. I killed the noise with door edge guard material on the leading edge of each plate.
No need to put up with wind-induced vibration. No need to turn up the radio. No need to buy anything.
Had the same problem. Solution: Half way up the strap, tie an old sock or a rag onto the strap.
Do NOT ignore the problem the way some people here are advising. That rapid strap vibration will break down the strength and integrity of the straps, and eventually they will fail. Then you have a loose kayak flying off your roof and causing a traffic accident that could kill people.
The number of twists depends upon the length of the section of strap. I like to use a half twist per foot of length exposed to the wind. The longer the unsupported strap, the more twists you will need.
Also see this article, here:
https://thcc.clubexpress.com/content.aspx?page_id=22&club_id=496051&module_id=257066
- John Rich