Tow bar angle

[EcoCivic]

Originally Posted by euromodder

It tries to lift the rear while pulling.
Thus making your tow car feel skittish, as if the rear wheels weren't on it ... sound familiar ?


Do you remember vectors from math lessons ?
No problem if you don't, but unless the towbar is level, whatever force happens to go through it will also result in an extra vertical force on your tow hook


Either up or down, depending on
- towbar angle
- what 's happening (you pull, or the towed car pushes you under braking)

Great information, thank you very much! Just out of curiosity, how would that change going up hills? Because like I said, my car felt a lot more stable and easier to control when it was going up hills, even small ones.

[Piotrsko]

Up hill you have the mass of the vehicle slowing the tow vehicle which is a stabilization force.

[EcoCivic]

Originally Posted by Piotrsko

Up hill you have the mass of the vehicle slowing the tow vehicle which is a stabilization force.

You mean because the vehicles are going slower? If so that's not it. I got up to 45 going up a pretty long but small hill and it felt perfectly stable, 45 on a flat surface would have been terribly unstable. I think it's because I was pulling it, meaning it didn't have the opportunity to push me.

[me and my metro]

I agree, just like applying trailer brakes to make a swaying trailer straighten out. Flat or downhill an improperly loaded trailer can push you around, but they tow pretty well uphill.

[EcoCivic]

Originally Posted by me and my metro

I agree, just like applying trailer brakes to make a swaying trailer straighten out. Flat or downhill an improperly loaded trailer can push you around, but they tow pretty well uphill.

That makes sense, thanks. That also makes me wonder if the way the weight is distributed between the 2 cars makes any difference. That car was relatively full of junk as is, but once I got there I put my luggage, jack, tools, tires, extra parts, etc in the towed car to make more room in my car for my dog. I am wondering if I might have made things worse by adding more weight to that car instead of to the tow car? If nothing else I would think that having the weight in my car (over the tires doing the braking) would be better for braking performance than having that weight pushing on my car. Thanks

[UFO]

Originally Posted by EcoCivic

Thank you for your help. I have not checked the alignment, but I don't remember it pulling while I was driving it. It's been years since that car has been driven though, so I may not be remembering correctly.

Was your tow bar pointing down as much as mine is? There's a big difference between "not perfectly level" and off by like 1 foot. LOL

Also, to be clear, I did NOT leave the axles completely out. What I did is I took apart 2 old axles I had laying around and took the ends off. I then took the axles out of the towed car and stuck those ends into the wheel hubs of the towed car and torqued them down, that way the wheel hubs are still being held together as they normally would be, just without being connected to the transmission. Hopefully that makes sense

My Datsun is very low to the ground, I think the attachment for the tow bar is about 1 foot off the ground, and the truck hitch about 1.5 feet. Enough to notice the truck diving while braking, so I imagine a foot of difference would be a bit sketchy.

[EcoCivic]

Originally Posted by UFO

My Datsun is very low to the ground, I think the attachment for the tow bar is about 1 foot off the ground, and the truck hitch about 1.5 feet. Enough to notice the truck diving while braking, so I imagine a foot of difference would be a bit sketchy.

Thanks. So your tow bar was higher on the hitch than where it attaches to the towed car, the opposite of mine. I am wondering if maybe you didn't run into stability issues because the truck you were pulling your Datsun with is much heavier than your Datsun, so it wasn't pushed as much?

[freebeard]

Great information, thank you very much! Just out of curiosity, how would that change going up hills? Because like I said, my car felt a lot more stable and easier to control when it was going up hills, even small ones.

In euromodder's helpful diagram at Permalink#19, Fy is vertical on the chart but not in real life. Against gravity, the tow bar is 'leveler'.

[UFO]

Originally Posted by EcoCivic

Thanks. So your tow bar was higher on the hitch than where it attaches to the towed car, the opposite of mine. I am wondering if maybe you didn't run into stability issues because the truck you were pulling your Datsun with is much heavier than your Datsun, so it wasn't pushed as much?

Maybe. My old Toyota is about 4000lbs (rated to tow 3500 with bumper hitch), the Datsun is 2500lbs. If your tow is the same weight or more than the tow vehicle, you are likely going to have stability issues, good point. You may not have enough braking ability either, not safe.

[EcoCivic]

Originally Posted by UFO

Maybe. My old Toyota is about 4000lbs (rated to tow 3500 with bumper hitch), the Datsun is 2500lbs. If your tow is the same weight or more than the tow vehicle, you are likely going to have stability issues, good point. You may not have enough braking ability either, not safe.

Thanks. I just don't understand why towing a trailer of a similar weight worked perfectly and this doesn't. If I remember correctly the trailer was pretty level, so that may have something to do with it. I actually accidentally got it up to 70 MPH because it pulled so well I couldn't even feel it back there.

As for braking ability, the brakes actually felt okay(ish) when I was pulling the trailer. The empty trailer wasn't noticeable and the loaded trailer wasn't terrible. More brake pressure was required to stop, but not terrible. However, I have rear discs, Hawk performance pads, Powerstop slotted rotors, and braided stainless brake hoses, so that helps some. I am way more limited by traction than by braking power, so getting a proper hitch so the front of my car isn't lifting up would probably help quite a bit.