2T van - 1 or 2 axles

[Graeme]

For an off-road van approaching 2T GVM, what are the significant pros and cons of single vs dual axles? I favour a single axle but perhaps 4 wheels are sometimes or often better than 2.

[bee utey]

Twin axle trailers are good on smooth roads, everywhere else a single axle will give you a better ride. Twin axle trailers put a lot of stress on your tow bar once you reach the limits of the axles articulation. Single axle trailers are also much easier to maneuver by hand using a jockey wheel.

[Graeme]

I should have stated for a van to be used on outback roads rather than an off-road van, so travelling over pot-holes and bumps rather than true off-road conditions.

[MR LR]

Our car trailer is single axle, 2500kg, I won't go back unless I need to go bigger. Tows like a dream on sealed and unsealed roads.

I'd go with single, but make sure it has a big axle and big bearings, and decent wheels and tyres. Primarily just because I much prefer how they tow, and it keeps weight down.

[disco 3 door]

It depend on personal preference, but if you go tandem make sure it's independent coils.

[bee utey]

The thing is, 2T isn't all that much for a single axle, if you use a quality set of hubs to fit 16" 4WD wheels. Match that with quality springs and some shock absorbers and your trailer will follow everywhere without any fuss. All of my trailers that I've built and owned over the last 35 years have been built to that pattern and they are far superior in towing comfort compared to the tandems I've had the misfortune to borrow. :)

[pop058]

If a tyre lets go (dramatically) on a single axle anything, the resulting ride is a little more exciting. I have had a few go over the years on dual axle trailers with no major side effects.

[bee utey]

If a tyre lets go (dramatically) on a single axle anything, the resulting ride is a little more exciting. I have had a few go over the years on dual axle trailers with no major side effects.
When I've had flats on my single axle car trailer I haven't noticed a thing until the tyre started shredding the mud guard. The trailer weight balance doesn't change at all. A flat on the rear of a tandem however can lead to wild swaying and a massive brown stain on your seat. I've seen that more than once.

[Graeme]

We're starting to think about a replacement van. Our current one is an old 14' Coromal to which I've fitted long off-road leaf springs and shocks and 30" tyres and it now rides rough gravel roads very well, although it only weights about 1T. The van's main deficiency is its lack of an en-suite but extra space and a longer bed would also be good.

We looked at some new Jayco Outbacks that have a single axle for the slightly smaller ones and duals for the next size up. I wondered if independent coil suspension duals might ride bumps better, acknowledging that 4 wheels hitting bumps could be worse than 2. I'm keen to keep the weight down but less impact felt by the tow vehicle is better.

We're also contemplating the pros and cons of pop-top vs caravan.

[pop058]

When I've had flats on my single axle car trailer I haven't noticed a thing until the tyre started shredding the mud guard. The trailer weight balance doesn't change at all. A flat on the rear of a tandem however can lead to wild swaying and a massive brown stain on your seat. I've seen that more than once.

I was referring to one letting go in a hurry, not just deflating and I have not experienced the major swaying (or staining :( ) when I have lost a front or rear on my trailers. Lucky I guess.

[MR LR]

Having had a blow out on our car trailer loaded, I can attest to it doing nothing erratic at all, but it is always loaded correctly.

Dual axles are the ones that try and steer the car, singles just follow. Even my 25 tonne single axle chaser bin is the same, but the dual axle versions buck the tractors around like mad.

[Slunnie]

I think duel axle.

Personally I think they ride the bumps a lot better as they have an axle that supports the trailer whenever one drop in a hole etc. It does change the ball weight no doubt as weights change between axles, but it has never worried the tow vehicle in my experience. Surprisingly, I actually think non-load sharing is also the way to go as long as your towbar is at the correct height. Re punctures, you get a puncture and you're hard pressed to notice it apart from the smoke.

I would also do leaf suspension and have appropriate leafs. My opinion is that independent suspension is more prone to failure because of the loads on the suspension mounts that hold the arms in place and because it point loads the chassis, where leafs provide a much better spread of load into the chassis using multiple points.

[Graeme]

Dual axles are the ones that try and steer the car, singles just follow. Even my 25 tonne single axle chaser bin is the same, but the dual axle versions buck the tractors around like mad.I hadn't thought of this characteristic, which would be at its worst on soft or slippery surfaces. However there's a huge difference between a 2.5T car turning a 2T van with close-spaced axles and a 5T tractor trying to turn a 25T dual axle trailer that also has a much shorter draw-bar.

A particular disadvantage of non load-sharing dual axles would be that raising the vehicle (air suspension) for gravel roads for more bump-stop clearance would put more load on the van's rear suspension and tyres, but perhaps not significantly and at least better than less load on the rear tyres. My current single-axle van sits slightly low at the front with the tow vehicle at normal height but level when raised 30mm for gravel roads.

[Graeme]

I would also do leaf suspension and have appropriate leafs. My opinion is that independent suspension is more prone to failure because of the loads on the suspension mounts that hold the arms in place and because it point loads the chassis, where leafs provide a much better spread of load into the chassis using multiple points.I agree with the mechanics and chose leafs for the old van particularly because new suspension was being fitted to a light-weight chassis. The Jayco single axle is solid with leaf springs whereas their duals are independent, both effectively 2 load points each side but not always equal load on the dual system.

Unless there's a significant concern for or against a single or dual axle configuration, the van choice will be based on other criteria.

[Pedro_The_Swift]

Every time I see a 18' single axle I cringe,,,
it just looks out of proportion,
and yes, by design 4 wheels are harder to shift at the jockey wheel,,
but its a small price ( I cant remember the last time I even tried:D) for the van towing straight.
and go the van,, popups are for kids just out of camper trailers:p

[bee utey]

I think duel axle.

Personally I think they ride the bumps a lot better as they have an axle that supports the trailer whenever one drop in a hole etc. It does change the ball weight no doubt as weights change between axles, but it has never worried the tow vehicle in my experience. Surprisingly, I actually think non-load sharing is also the way to go as long as your towbar is at the correct height. Re punctures, you get a puncture and you're hard pressed to notice it apart from the smoke.

I would also do leaf suspension and have appropriate leafs. My opinion is that independent suspension is more prone to failure because of the loads on the suspension mounts that hold the arms in place and because it point loads the chassis, where leafs provide a much better spread of load into the chassis using multiple points.

All the trailers I've hated towing the most were set up that way. I was always glad to hand them back after the trip, hopefully to never tow them again! :p

But then I've never had a three ton truck to tow a two ton trailer, perhaps a fully loaded leaf sprung 4wd is only marginally less unpleasant with this combination. :angel:

[weeds]

I would go single.......based on my old pop top that probably weight closed to 2t.....would have been nice to have brakes way back than

Fit quality tyres, I had one tyre (probably a million years old) blow on the van at 100km/hr towing with a two door rangie. No ill effects, just pulled over and fitted the spare. Than brought two light truck tyres.....

[Slunnie]

All the trailers I've hated towing the most were set up that way. I was always glad to hand them back after the trip, hopefully to never tow them again! :p

But then I've never had a three ton truck to tow a two ton trailer, perhaps a fully loaded leaf sprung 4wd is only marginally less unpleasant with this combination. :angel:
Really, I much preferred this setup. It worked really well for me.

[Homestar]

If a tyre lets go (dramatically) on a single axle anything, the resulting ride is a little more exciting. I have had a few go over the years on dual axle trailers with no major side effects.

I had the back left tyre let go on a borrowed tandem some years ago (3,000kg rated, electric brakes being towed with the RRC at around 80 at the time). I had a car on the trailer, which was balanced well and plenty of weight over the draw bar and it was towing well. Once the tyre went, the draw bar unloaded as the weight pivoted over the remaining wheel to the back and I had a real tail slapper on my hands. It's the closest I've come to having an accident while towing - a real brown trouser moment. Not sure what the result would have been without electric brakes - pretty bad I think.

I haven't experienced the same with a single axle, so I have no comparison.

[Pedro_The_Swift]

of course for the totally paranoid amoungst us,,
http://www.aulro.com/afvb/attachments/trailers-vans-campers/102974d1449958389t-show-us-your-caravan-camper-trailer-camping-trailer-p1010331y.jpg

Thanks Stephen;)

[ozscott]

I had blown out - rear tyre - on my 2 ton boat trailer at 100 kph and it was just a lazy pull over on the Logan Motorway and change it....it was nicely taking the weight on 3 wheels. Custom leaf springs and nicely set up trailer - beams. Impossible to move sideways without the vehicle attached is the only issue.

My van is single axle independent suspension. Tows very well. Cant help wondering what manner of drama it would create if it had a sudden blowout...i run light trucks on all trailers.

I have a 1.7 tonn caged up box trailer and it tows beautifully also...heavy duty leafs and beam. Needs a load though.

Cheers

[Graeme]

We ended-up with a tandem trailing arm independent with coils & shocks and Alko stability control which hopefully will assist with the RR's trailer assist if a rear van tyre blows.

[Mick_Marsh]

Been thinking about this for a while. My 2t tandem tows beautifully. The single axle 1t Crump & Cornish is much easier to manoeuvre in tight spots. The Track is brilliant.
If I was towing a van in the bush around tight tracks, I'd probably lean towards a single axle.

[Graeme]

If I was towing a van in the bush around tight tracks, I'd probably lean towards a single axle.and hopefully something that weighed a good deal less than 2T empty.

[joel0407]

This is actually my preference.


https://www.aulro.com/afvb/images/imported/2016/01/32.jpg




I wanted to build it into my last trailer build but at under 500kg I couldn't justify it. I don't know what its called but single spring, single axle but seesaw with tandem wheels on each end.


https://www.aulro.com/afvb/images/imported/2016/01/33.jpg


I've seen it referred to it as simplicity suspension but I think that's the brand name.


Happy Days

[Aaron IIA]

Walking beam. The same as the back end of graders.

Aaron

[joel0407]

Walking beam. The same as the back end of graders.

Aaron





Yeh, That's it. I have towed farm trailers with it and it seamed to work very well. As the trailer goes over a bump or pot hole, if the obstacle is 100mm in height the vehicle is only affected by 50mm as each wheels passes over the obstacle. It's not quiet that simple as the single spring needs to support the whole weight so even though there is half the movement this doesn't translate in to half the bump being felt by the vehicle.