Or becoming a big parachute
Thanks to a sturdy rack and multiple tie downs I can attest to the attractiveness of an aerial view of Gary Indiana
I think grief leads to safety
Yesterday, every time I heard a weird flapping noise I would stop at the next rest area and one time I even got off at an exit. -did a walk around and tugged at everything - found it all to be nice and tight and continued on my way.
Jack L
Can I laugh?
>Very seldom need that front and rear nonsense except when I want to protect the bow of an 18’-6", 19 pound carbon fiber knife point hull from breaking off when a big rig comes by.
Can I laugh when the bow of your boat flips up while you’re driving? It would be hard to keep a straight face.
sure
Like I said, shrink-wrapping the boat to the car is the only safe way.
I think the next time
I’ll just epoxy the boat to the roof and solve all my problems!
Jack L
You can’t be serious
– Last Updated: Apr-30-14 12:31 PM EST –
My front tie-downs angle forward at a flatter angle than 45 degrees. Being in an inverted "V" shape, they help a little bit at keeping the front end from moving side to side (though I have better ways of controlling that motion). However, if the boat ever tried to flip up such that it might break, the rope wouldn't be able to stop it until the movement was "too far", so it sure wouldn't stop the boat from breaking as you describe. At that angle of rope orientation, it would take a LOT of movement of the boat just to create a small amount of stretch in the rope (and the rope MUST stretch when taking on tension. Some rope materials do it more than others). A rope angled almost straight down would be more efficient at stopping motion relative to the rate of stretch of the rope, but the stretch would still occur. Therefore, to actually keep the boat from lifting at all as the upward force develops, you'd need to cinch the rope tight with boat-breaking force just so it would have enough of the stretch taken out of it to stop the motion caused by a similar boat-breaking force applied in the upward direction. Do you understand that part? Do you see why your idea is just not making any sense when one accounts for real-world physics?
Besides, some of my boats are pretty tough, and the front bar would tear out of the roof before the boat started to break, and again, that would happen whether the rope were there or not, because the rope MUST stretch in proportion to the tension applied, and only a fraction of an inch of boat motion would be enough to rip the front crossbar out of the roof. I used to carry an aluminum Jon boat on a Subaru, and if any boat would have lifted as you describe it would have been that one. In that case the front ropes went almost straight down (the best orientation to resist upward movement of the boat), but were never more than hand-pull tight, so if the boat were to lift with the kind of force you describe (enough to break a canoe), it STILL would have lifted several inches until the ropes got tight enough to resist that force. I never once saw any trace of lifting action though. Also, it's worth noting that when carrying that boat on that car, I used strong elastic straps for the main tie-downs, so the boat could have lifted a little bit if pushed hard enough. When I was a kid, my dad always strapped down boats with super-thick bungies, and the front rope was just there as a safety line (only hand-pull tight), and those boats never lifted either.
Are you the one who recently said the stern of a canoe would lift and break something if the boat were loaded rearward of center on the racks? If so, I'm probably wasting my time talking about real-world evidence for what these forces can be. I can show you the math that explains why forward- or side-sloping ropes provide much less ability to stop an upward movement of the boat (which combined with actual observation is proof that that such strong force pushing the front end up does not occur at all), at least if anything you say makes me think you would even understand such a thing, so that it would be worth my time (it would take me longer than this post did).
Quick Illustration For You
– Last Updated: Apr-30-14 1:28 PM EST –
Here's a way you can demonstrate for yourself that ropes angled forward won't stop your boat from moving upward (and as I described above, this in turn shows that any force which might be causing this to happen must be pretty minor).
Set your canoe on the roof with bow tie-downs angled substantially forward or sideways (say, a 45-degree slope). You may not do it that way, but lots of people do and have had no failures so this makes the point. Put ONLY the rear crossbar strap on the boat, not the front one. Now, lift the front of the boat as hard as you can. You may need two people, lifting the bow by means of a 2x6 or something reaching across the car's hood between you. Notice how high you can lift the front of the boat in spite of the ropes being there. See how the harder you lift, the tighter the ropes get and yet the bow still goes higher as you increase the lifting force too? The kind of force of the wind that you describe would be many times stronger than the force you can provide in this test, that is, if it can do what you describe, and would lift the bow even higher before the front ropes halted that motion. Now imagine that the front crossbar strap is in place and the wind lifted the boat this same amount (you can already see that if the wind wanted to lift the boat, it could and would). Can you see that your boat would break, or the front cross bar would rip loose from the roof, whether the ropes were there or not? Limiting the motion by means of the front ropes to one foot, or even several inches, wouldn't be enough to stop the damage from happening.
This should make it clear that the lifting action you describe simply doesn't happen. You'd see some motion of the boat if it were. The force may be there in tiny amounts, but not to the degree that will lift up the front of the boat and break something.
I was just thinking about that
I think a whole lot of discussion centers on the method of securing when in fact it’s the securer and how thorough they are that’s left out of the equation. IMO, if your kayak flies off the roof after you think you’ve secured it adequately to the rack - then you haven’t. I’m sure plenty of failures are actually “operator error”, because I know too many people who have never lost a boat or rack even though they drive in the same conditions as everyone else.
Yes, and my observations and this…
– Last Updated: Apr-30-14 1:47 PM EST –
... proposed demonstration are simply ways of showing what can be deduced about the forces that are present. It's not hard to see that the force described by Birren is in his imagination. To put it in the simplest terms of all, my bow ropes never get noticeably tight while I'm driving, which shows the boat isn't adding any tension to them that wasn't already there when I pulled them semi-tight with my hands. It really doesn't get any simpler than that. Those ropes help a little with crosswind resistance, but are mainly there to "catch" everything if something else fails.
I don’t worry about it lifting up.
If I didn’t have the inverted V ropes on the front, my worry would be it breaking off from one side or the other.
You evidently have never hauled an ultralight canoe with a long overhang over the front bar.
You can laugh till the cows come home, but I know my stuff is secure.
Jack L
this possibility?..($.005)_worth
– Last Updated: May-03-14 11:39 AM EST –
If things aren't going well Jack...if any of your doors can provide a solid hold...for running strap(s) over any/each door for a solid tie to any/each thwart(at the gunwale)...should provide some side-to-side prevention. You can always tie in a knot to hold(from inside)...
Sorry if I've repeated anything said previous.....
Steve