Thread: Building a small covered car trailer

Hi you will need to go dual axle, new parts are best and easier to work with.
With the subaru liberty waggon I find ts on the small side.
Its just too easy for a trailers to push a small cars around going down hills ect.
Tony

Sounds like an interesting project, especially the bit about "aquiring" a race car.

Firstly, I would not scrimp too much on the running gear, new axles, springs and coupling shouldn't break the bank and you wont have to worry about things like bearings and brakes for a while. It also allows you to get an axle exactly to your specifications in terms of length and capacity.

If you can keep your weight under 1500Kg, you can get away with a single axle setup, but you'd continually have to be aware of what your putting in the trailer. Building it as a single axle, you'll also need to be fairly accurate with your axle placement. Too close to the centre of gravity (not necessarily the centre of the trailer), and the trailer will not tow well, constantly trying to swap ends with itself and you. Too far to the rear, and the trailer will tow fantastically, but will probably exceed the towball weight rating for a smaller tow vehicle.

As you say, if the trailer i being towed by more than one tow vehicle, then over-ride brake would be the way to go. As for which type... Mechanical drum is by far the cheapest, but there's quite a delay in braking effort as quite a bit of movement is taking up the slack in the cable, and you can't have it too taut or the brakes will drag and overheat. Hydraulic is a bit dearer, mainly due to the coupling, but the hydraulics will work pretty much instantly, as long as everything is kept adjusted and maintained.
But, ask yourself, how often would it be towed by other cars? Because once you've had Electric, you never go back.

You're right, 09sr5's is a fairly heavy duty trailer and could quite easily handle 4000Kg. Yours on the other hand would get away with 75x50 main rails and drawbar, and 40 square for the rest. 25mm sq would be perfect for the upper frame, and remember, triangles are your friend.

The floor is a personal choice. Timber can be just as heavy as steel as it has to be much thicker. And with timber, once you cut it, it's difficult to rejoin. A steel floor is lighter for similar strength, but on a racecar, I would steer clear of checkerplate, mainly for where the wheels go, as the tread on the checkerplate tends to make and leave an impression in your soft, sticky race rubber. If your budget will spring for it, smooth 3mm aluminium plate would be ideal. Lighter than steel, and no need to paint it.

Good luck with it, and keep us posted on your progress.

If you can keep your weight under 1500Kg, you can get away with a single axle setup, but you'd continually have to be aware of what your putting in the trailer. Building it as a single axle, you'll also need to be fairly accurate with your axle placement. Too close to the centre of gravity (not necessarily the centre of the trailer), and the trailer will not tow well, constantly trying to swap ends with itself and you.

Have you tried towing a "lighter" weight tandem on the Suburu? If it was me I would go the tandem, I just like the way they sit out on the road. Then again I have a Falcon Tradesman ute to tow one with.

antoni sounds like he has had experience towing with a Suburu. Have no personal experience with one myself, but would some suspension work on the back help out here? At least so its sits better when towing. Yes I know ideally there is no substitute for extra tow vehicle weight.

As the man says, electric is ideal. Ally where possible/practical to keep the weight down.

Hi Wannaberacer 60,
Have been building a tandem similar in size to the one your after. (see 'Trailer for long loads' in this forum.)
Size is 4.5m x 1.5m with 1.5m drawbar. 75x50x3mm main frame and 100x50x3
drawbar
All up I have spent $2700.00 and am in the final stage of painting.
This includes new tyres and fancy white rims.
While it might be cheaper to build it yourself, it is a lot of hard work and a fair bit of time. You really must love the challenge of doing it yourself or it's not really worth the hassle.
Me, I just love the whole workshop thing and couldn't care if it cost twice as much.
Write out a list of all components you will need and be surprised at how long that list will be.

Hi no did not have a Suburu had some small cars not for long.
They can get pushed a round in the wet and I did in 1100 kgs statwag once towing a small race boat just mowed the grass bit.
The last 15 years been useing a F250 for towing they go they stop , just no good for parking in the city,,,,,,
Tony.

Originally Posted by antoni

Hi no did not have a Suburu had some small cars not for long.
They can get pushed a round in the wet and I did in 1100 kgs statwag once towing a small race boat just mowed the grass bit.
The last 15 years been useing a F250 for towing they go they stop , just no good for parking in the city,,,,,,
Tony.

or fuel economy.

i would be be wary of towing that mutch weight with a small car.

Hi f250 on gas and a round 4ks to the ltr , also got a comie vn 6 to 7 ks to ltr ,
Its not as good when towing with the v6 uses more gas.
The boat was not big, as it was a race boat 4 cly hydro on single axle trailer.
just wide . best to have tow unit bigger than what you are towing.
Dual axle is so must easer there not so must load on the tow car .
Tony.

Hi All,


Thanks for all the constuctive suggestions. Preliminary thoughts as follows still open to suggestions though.

*Internal dimensions 4.5m X 2 M ( this also allows for a FF which is up to 1850 mm wide which may make trailer easier to sell at later date and room for bench across front

*Drawer bar 1.5 m long 100 X 50 X 3

*External frame 75 X 50 X 3

*Internal cross members at 750mm centres 50 X 50X 3

*wall/enclosure frame 1.8 m high, 25 X 25 X 2

*Dual axle with electric brakes ( do both axles need brakes?) Ford wheels

*Undecided about floor and wall covering but will take all suggestions on board.

As far as time and effort involved I am a member of active mensheds many of who are retired metalworkers desperate for something to do so labour and time not a problem so fortunately will probably only have to supply the coffee and beer at end of each day.

Should have price on metal soon and have spoken to Carasel about a package for everything else,excluding floor and cladding hope to bring for $2.5- $3K which is still about 1/2 price of commercially built trailers

Thanks again

Change of user name...??

Legally, you won't need 4 wheeled brakes under 2000Kg, but it's not much extra to order the rear lazy axle with Electric mounts fitted. That way, you conversion to 4 wheeled brakes is a bolt-on fit. Single axle wise, they're good for 1500Kg, so you're OK there.

Sizings look OK. Are you going to taper the front down along the drawbar? The trailer in the picture looks good, but I would be very concerned that the drawbar looks like it only extends back about a foot or two past the front of the trailer. It should really tie back to the front hangers so your accelerating and braking forces are directly acting on the coupling and springs rather than relying on the chassis and welds in between.

Yonnee,

You are observant I used the the wrong account the menshed one instead of my personal account. Thanks for your comments though.

In regard to the tapering of the front I always had the impression that it was best to have a clear 1.5m from the front to the towbar but if I could grab another 500mm from this by following the draw bar angle it could give more storage room with minimal increase in material and weight and improve the aesthetics of the trailer.

Project seems to be getting bigger (heavier) and note other comments about using Subaru seems will need something bigger

How old a Subaru? You'd have to be careful what the towing capacity actually was. We, until recently, had an MY97 AWD RX Wagon, and its towbar was rated 1200Kg, and I'm not sure if Hayman Reece have a Heavy Duty option (they've removed their catalogue from their website!!).

Hi All,

Have received prices for the structural steel, all steel required, new and galvanised, as stated previously supplied and cut for about $900 inclusive of GST, which just means one or two long weekends with enough helpers to build chassis.

Was disappointed however with price of sheet metal, new aluminium over $2100, new steel about $1600. Am happy to use second hand material for this, does anyone know here can source 2-3mm sheet steel (or even better ally) for floor and .5-1mm for walls ( will adjust framing depending on thickness of sheet). Are there companies which dismantle damaged semi-trailers bodies or sell used sheet in Sydney, could not find any on Google and could only find used sheet in Melbourne. Assuming can source sheeting at reasonable price can build trailer for $3000-3500, less than 1/2 price of comparable trailers advertised on racing websites.

Some of the larger steel suppliers in Melbourne have what is called 'down graded' steel plate which is cheaper than 1st grade stuff. Might be worth ringing around and asking for down graded steel. Might be the same for aluminium to.

For the wall sheeting, there's a sandwich type of sheeting that you might like to consider? It is made of two sheets of thin aluminium with a black polycarbonate(?) centre and is about 5mm thick. The face side can come in different colours . . . I've seen a black and a white version. You can router a deep V groove to just the right depth on the inside so that the sheet can be folded to form a perfect external corner (e.g. no need for external cover angles to hide butt joints). Wouldn't rust and wouldn't need to paint it. I think places like Metaland sell it?
Sorry, I just know it exists and looks good as trailer wall cladding. Hopefully someone else will know what I'm talking about and be able to help out with any other advantages, disadvantages, prices and where to get it, etc.
Cheers