Wheel Net Trailer Tie-Down (No Cross The Straps Controversy)

[Rick2004LJ]

Yes I would rather tie-down by axels but won't work on my setup - so no "cross the Straps" debate needed....

I have hauled all manner of cars by tying down by the tires using several different methods, and it looks like it is an acceptable method for our Jeeps. Now just trying to decide what will work best with my Jeep & trailer set up.

My choice would be wheel nets straight down to trailer:

Problem is I dont have the perfectly located tie-down point. I have V-Track (or L-Track/VersaTie) but it is not centered directly under middle of the tires - Opinions on if slightly offset would be a problem? :

Another option is an axel strap through the wheel:

Would be simple single attachment point (where off-set would not be an issue) and will work with my wheels.

Just questioning if this option is secure for the weight and "bouncy" nature of our rigs? Any problem using this with the beadlocks?

I have also used "Lasso" style Straps that tie down to the rub rail/Stake Pockets. Again would be simple single attachment point that would work with my trailer. Concern here is pulling laterally on the top half of the tire/wheel?

Would love to hear other folks experience using any of these methods and opinions on best option for my setup - fire away.
Thanks

 

[mrblaine]

Yes I would rather tie-down by axels but won't work on my setup - so no "cross the Straps" debate needed....

Only because you don't want it to but that is okay.

I have also used "Lasso" style Straps that tie down to the rub rail/Stake Pockets. Again would be simple single attachment point that would work with my trailer. Concern here is pulling laterally on the top half of the tire/wheel?

The tie down lasso isn't going to exert any more pressure on the tire and rim than going around a corner or driving it through a wedge offroad where the bottoms of both tires are forced together.

 

[NashvilleTJ]

My concern with a strap though the wheel would be the sharp edge on the bead locks damaging the strap.

 

[Rick2004LJ]

Only because you don't want it to but that is okay.

The tie down lasso isn't going to exert any more pressure on the tire and rim than going around a corner or driving it through a wedge offroad where the bottoms of both tires are forced together.

Thanks for the input. I really would like to do axels, guess I need to find someone smarter than me to show where.

 

[Woodrow]

I have hauled by strapping to the axles which is OK but there is surprisingly little real estate on my TJ axles to make this easy. So now, I have a version of these (https://www.macscustomtiedowns.com/straps/automotive/tire-block/e-track/p/511002/)
Mine are longer for bigger tires and use the heavier HD tube track sold by the same company. Very versatile. Works for Jeeps and sports cars. Down sides are the track needs to be built into your trailer and at the correct width. Turns out 63” works well for about everything I would haul. Also spendy.

 

[Rick2004LJ]

I have hauled by strapping to the axles which is OK but there is surprisingly little real estate on my TJ axles to make this easy. So now, I have a version of these (https://www.macscustomtiedowns.com/straps/automotive/tire-block/e-track/p/511002/)
Mine are longer for bigger tires and use the heavier HD tube track sold by the same company. Very versatile. Works for Jeeps and sports cars. Down sides are the track needs to be built into your trailer and at the correct width. Turns out 63” works well for about everything I would haul. Also spendy.

I have a set of those too that I use hauling low ground clearance sports cars - they are awesome. I played with them on the Jeep but the single strap over those big fat 37's just looked too small. No reason they wouldn't work I suppose?

 

[Rick2004LJ]

Only because you don't want it to but that is okay.

The tie down lasso isn't going to exert any more pressure on the tire and rim than going around a corner or driving it through a wedge offroad where the bottoms of both tires are forced together.

mrblaine - I know you prefer the axels, but do see any problem or reason not to tie down by the wheels/tires?​

​

 

[Steel City 06]

I haven't ever hauled a car, so I'm a bit out of my swim lane here.

However, for most loads, the strapping system must be able to withstand 0.8g forward deceleration, and 0.5g in other directions. With smaller trailers, 1.0g is a better design especially with improvements in braking systems. At an absolute maximum, 1.5g is the highest you would generally design a strapping system for, as that is what the receiver and trailer attachment systems themselves are designed for (using SAE J684). Beyond about 0.8g lateral and you have high likelihood that the trailer will simply tip over, so lateral accelerations past 0.8g are rarely considered (except if the cargo needs to be retained during a flip).

https://www.fmcsa.dot.gov/regulations/cargo-securement/cargo-securement-rules

Cargo securement can be done either by direct retainment, or by using force to increase the friction between the object and the trailer bed to an acceptable level. Due to stiffness incompatibility, a combination of these methods cannot be relied upon increase the cargo retention capability over the stronger method alone. In addition, the securement method needs to minimize load shift, which can contribute to instability resulting in loss of control or loss of cargo.

Since the car is on wheels, it needs to either have the wheels secured from turning, or otherwise mount in a way that excludes the wheels from turning. Generally, it's easiest to simply anchor the car itself from moving, using straps to hard mounting points to keep it from moving.

So, using the example of a 4,000 lbs TJ, the bare legal minimum would be to restrain it from forward deceleration of 3,200 lbs, and lateral accelerations of 2,000 lbs. (4,000 is a better target for forward deceleration, 6,000 is the max you would consider.)

Let's say you use two straps looped around the rear axle, and then run them at a 45° angle to the bed to an anchor point directly behind it. The actual force on the straps is greater than the deceleration load because of their angle, in this case equal to the deceleration load divided by cos(45°). For a 4,000 lbs deceleration assumption, this means that the straps combined need to withstand 5,657 lbs. So two 3,000 lbs WLL straps will suffice. Increase the bed angle past 45° and you will need bigger straps. (Same case as when a compound angle is used).

As for lateral acceleration, 0.5g is relatively achievable with friction between the tires and the trailer bed. However, to guarantee it, you'll need to add additional downforce, as in a number of conditions, the coefficient of friction between the trailer bed and tires may be less than 0.5.

Say you use those two 3,000 WLL straps on the rear and two equivalent ones on the front, both at 45° angles. You crank them down with the ratchet to about 1,500 lbs preload each. Each strap contributes 1,500×sin(45°) lbs of downforce, resulting in a total of 4,242 lbs of downforce, pretty much doubling the friction you originally had. So you can get the 0.5g requirement even if the coefficient of friction is as low as 0.25, which generally applies even in the case of a wet trailer bed. (The only common scenario it might not work for is an oily trailer bed.)

The 0.5g acceleration in the up and down plane is pretty much taken care of by gravity. Granted, with a car like a TJ, this may result in some dynamic effects. Hence oversizing and overstrapping may be a good idea.

As a fail safe, it's not necessary a bad idea to leave the car in 4Low and lock the lockers, and then crank the parking brake. While the friction between the tires and the trailer bed is generally not enough (practically or legally) to prevent the load from rolling off the trailer in a 0.8g deceleration, in practicality the sliding of the tires on the bed will absorb some of the energy as the straps on the rear tighten, thereby reducing the peak load that they see. (That shock load is why you have to rely on the WLL and not the breaking strength of the straps.)

 

[mrblaine]

mrblaine - I know you prefer the axels, but do see any problem or reason not to tie down by the wheels/tires?​

​

I never prefer the axles.

 

[mrblaine]

I haven't ever hauled a car, so I'm a bit out of my swim lane here.

However, for most loads, the strapping system must be able to withstand 0.8g forward deceleration, and 0.5g in other directions. With smaller trailers, 1.0g is a better design especially with improvements in braking systems. At an absolute maximum, 1.5g is the highest you would generally design a strapping system for, as that is what the receiver and trailer attachment systems themselves are designed for (using SAE J684). Beyond about 0.8g lateral and you have high likelihood that the trailer will simply tip over, so lateral accelerations past 0.8g are rarely considered (except if the cargo needs to be retained during a flip).

https://www.fmcsa.dot.gov/regulations/cargo-securement/cargo-securement-rules

Cargo securement can be done either by direct retainment, or by using force to increase the friction between the object and the trailer bed to an acceptable level. Due to stiffness incompatibility, a combination of these methods cannot be relied upon increase the cargo retention capability over the stronger method alone. In addition, the securement method needs to minimize load shift, which can contribute to instability resulting in loss of control or loss of cargo.

Since the car is on wheels, it needs to either have the wheels secured from turning, or otherwise mount in a way that excludes the wheels from turning. Generally, it's easiest to simply anchor the car itself from moving, using straps to hard mounting points to keep it from moving.

So, using the example of a 4,000 lbs TJ, the bare legal minimum would be to restrain it from forward deceleration of 3,200 lbs, and lateral accelerations of 2,000 lbs. (4,000 is a better target for forward deceleration, 6,000 is the max you would consider.)

Let's say you use two straps looped around the rear axle, and then run them at a 45° angle to the bed to an anchor point directly behind it. The actual force on the straps is greater than the deceleration load because of their angle, in this case equal to the deceleration load divided by cos(45°). For a 4,000 lbs deceleration assumption, this means that the straps combined need to withstand 5,657 lbs. So two 3,000 lbs WLL straps will suffice. Increase the bed angle past 45° and you will need bigger straps. (Same case as when a compound angle is used).

As for lateral acceleration, 0.5g is relatively achievable with friction between the tires and the trailer bed. However, to guarantee it, you'll need to add additional downforce, as in a number of conditions, the coefficient of friction between the trailer bed and tires may be less than 0.5.

Say you use those two 3,000 WLL straps on the rear and two equivalent ones on the front, both at 45° angles. You crank them down with the ratchet to about 1,500 lbs preload each. Each strap contributes 1,500×sin(45°) lbs of downforce, resulting in a total of 4,242 lbs of downforce, pretty much doubling the friction you originally had. So you can get the 0.5g requirement even if the coefficient of friction is as low as 0.25, which generally applies even in the case of a wet trailer bed. (The only common scenario it might not work for is an oily trailer bed.)

The 0.5g acceleration in the up and down plane is pretty much taken care of by gravity. Granted, with a car like a TJ, this may result in some dynamic effects. Hence oversizing and overstrapping may be a good idea.

As a fail safe, it's not necessary a bad idea to leave the car in 4Low and lock the lockers, and then crank the parking brake. While the friction between the tires and the trailer bed is generally not enough (practically or legally) to prevent the load from rolling off the trailer in a 0.8g deceleration, in practicality the sliding of the tires on the bed will absorb some of the energy as the straps on the rear tighten, thereby reducing the peak load that they see. (That shock load is why you have to rely on the WLL and not the breaking strength of the straps.)

What safety factor is used to determine WLL on tie down straps?

 

[bucky]

I use these when strapping to acels.

 

[bucky]

In my opinion the shallow angle strapping like this is fine for lateral forces but does not help much with vertical movement.

 

[Steel City 06]

What safety factor is used to determine WLL on tie down straps?

Generally 3:1 relative to breaking strength, sometimes higher or lower depending upon the strapping system used. Some ultra-cheap straps are only rated using 2:1, which is unfortunately misleading. (For comparison, crane slings and components are generally 5:1; however, in that use case the consequences of breakage tend to be much higher.)

It's to account for several factors:
(1) - variation in strap production strength
(2) - dynamic effects due to load shift, particularly for plastics-based straps, which stretch appreciably
(3) - mitigate the effects of accumulated strap damage from repeated near-break events

Note that it is usually rated to failure and not necessarily just yielding. You may cause permanent damage to your hardware at a lower load than the load required to actually make it break.

It is also NOT intended to account for derating due to certain tie-down configurations or strap angles. For example, using it in "choker" versus "basket" requires a derate same as it does for a crane sling.

 

[B00mb00m]

mrblaine - I know you prefer the axels, but do see any problem or reason not to tie down by the wheels/tires?​

​

Why do you keep thinking axles are better? Tire baskets are the ideal spot to anchor it doesn’t impart any load into the Jeep that it doesn’t see under wheeling conditions. Im planning to switch over to tracks with wheel baskets when I don’t have other things to spend money on.

 

[Woodrow]

I have a set of those too that I use hauling low ground clearance sports cars - they are awesome. I played with them on the Jeep but the single strap over those big fat 37's just looked too small. No reason they wouldn't work I suppose?

I think the weight of the vehicle is important and TJs are usually fairly light. In addition to solving the problem of no great place to strap around the axle, I like the redundancy of 4 connections independently holding the vehicle.

 

[Longwhitejeep]

I have been thinking about trying these on my wood deck trailer. Or making something similar to fit my needs as I would like to switch to an over the tire setup. I have a wood deck.

This type of solution could work for the lasso style if installed on the outer edge like their video. You would have a tie down point straight down.


https://www.macscustomtiedowns.com/track/specialty/hd-tube/track/p/290008/

 

[Apparition]

Anybody have any experience with dog bone straps? Typically seen on rollbacks

Seems like an easy way to strap your rig down and allows significant adjustability.

 

[mrblaine]

Anybody have any experience with dog bone straps? Typically seen on rollbacks

Seems like an easy way to strap your rig down and allows significant adjustability.

View attachment 426618

I'd be more comfortable with that style if it had a longer one that went from the middle of the tire down to the dog bone. All of our straps for the most part are dependent on the tires staying inflated. Even if they lost a fair bit of air, most of the other styles will stay in place. That one looks like it would easily fall away if the tire lost some air and it was set up too close to the middle of the tire's diameter.

 

[bucky]

Here is a good wright up on securing a vehicle. While I do not buy my tie down equipment from them I do buy there semi cargo netting. I get most of my equipment from US Cargo Control. The majority of my trailers use D-rings my show truck hauler uses E-tracks.

https://www.myteeproducts.com/blog/car-tie-down-straps/

 

[Apparition]

I'd be more comfortable with that style if it had a longer one that went from the middle of the tire down to the dog bone. All of our straps for the most part are dependent on the tires staying inflated. Even if they lost a fair bit of air, most of the other styles will stay in place. That one looks like it would easily fall away if the tire lost some air and it was set up too close to the middle of the tire's diameter.

I saw these when searching for the dog bones. Significantly different setup than the dog bone though.