Modifying My Car Trailer

[75coupe]

so I want to change the tie down system on my car trailer.

Im going to use two 80mm wide ratchet straps, each to run from front of trailer over the front wheel then over the rear wheel,

just like below, except my trailer is a complete sheet platform.

and Ill be using square u bolts to run the strap through if that makes sense.

What I need to know is what size steel I should use as reinforcement for the u bolts.

Im thinking 50x50 square tube 5mm? thickness, running the entire wide of trailer welded to each side rail welded at intervals to underside of sheet platform.

Any advice?

[X-Modcarz]

50x50 x 5mm thick will do your job perfectly. This is assuming your trailer bed width is 2m or less. If you have rails in between, eg - 4 rails for the length of the trailer, then you only need to run the tie down 50x50 between the 2 outer rails. Hope that helps.

(PS - I am a structural engineer and designed my own car trailer too.)

[75coupe]

Oh sweet, i had visions of the car deforming the metal and go flying off on the highway..

Thanks for the reply, what method of tie down system do you use???

[75coupe]

And what do you think minimum wall thickness would do the job...

[KiwiRS4T]

I think your tie down idea looks dodgy. A sideways impact or even some potholes could see the car move sideways. I think the normal 4 ties downs would work better.

[warps]

Nothing wrong with that tie down system - just use individual ones on each wheel ( even 2 wheels will do the job). This system is used on tow trucks, so it's clearly effective.

Edit: i meant car transporters, not tow trucks.

Edited March 26, 2016 by warps

[75coupe]

Well my trailer was stolen so ill have to work on replacing it before i can fit it out...

But thanks for the suggestions...

[MBS206]

That epically sucks that it was stolen!

As an alternative that Neil and I spitted a few years back at the Australian Hill Climb champs, a guy was using boat rollers with a bracket bent up that slipped through the floor of the trailer. It meant the strap was all above the trailer deck and easily accessible, and it merely required four holes per wheel to be drilled in the deck. This also means no climbing under or over the deck. Ie super easy to do up in the pissing down rain!

[donburtron]

Nothing wrong with that tie down system - just use individual ones on each wheel ( even 2 wheels will do the job). This system is used on tow trucks, so it's clearly effective.

Edit: i meant car transporters, not tow trucks.

Tow trucks use them aswell

I sell can am commanders and we tie them down the same way.

It straps the wheels town and the suspension carries the loan of the unit on the trailer while towing it.

Its the best way i have toe anything down in 6 years of towing car and bikes around.

It also help with the rough towing.

Sorry to hear the ops trailers stolen.

That bullshit

[neil_se]

Seems to me that there would be too much friction to get the strap tight over the front and rear tyres (with sticky tyres anyway). With the 4 ratchets positioned as per the top photo, accessing them would be difficult and the height of the ratchet itself would be too tall for the ground clearance of most race cars.

On my previous trailer I used choker straps which worked very well. There was still a lot of friction to overcome on a single sticky tyre. My new Tilta came with it's own over-the-tyre system.