Pete says that if you have single axle and 'do' a tyre - you're done for, if you have dual axle, at least you still have one good wheel on that side to continue for a short distance if you have to.
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Pejay are travelling in a 2014 Holden Colorado LTZ Twin Cab Ute + 2013 Coromal Element van
Have had both duel and single over the years, have had an tyre related accident in both vans, sustaining heavy damage, thankfully insured, but the latest van is 17 foot with the axle set well back , makes for a very smooth ride, as for duel they ride well too , so it all really what you prefer , with the duel axle we only carried one spare and with the single we also carry one spare..
Most people who reckon that a twin axle van is more stable base this on one of two premises. If they have derived this from experience then in all probability the vans they are comparing are a long two axle model and a short single axle van. If you want to make a real comparison then you need nearly identical vans to compare.
The others use the "common sense" approach. Well Albert Einstein told us what common sense is - "Common sense is nothing more than a deposit of prejudices laid down by the mind before you reach eighteen." They think that two close coupled non steering axles will hold something straight when it is running at speed. It might be difficult to rotate the van on its axle when at rest. However at walking speed I can steer an 5.5 m van very easily, it's not much more difficult then steering a single axle van. I found this out when I was swapping vans when I traded my two axle van for a single axle one. If a walking speed considerable reduces the effort required to turn a twin axle van then how much "stability" will be left at road speeds?
A few years back I traded a twin axle van for a single axle model that was predominantly the same layout, length and weight. At the same time a mate went through the same exercise. Neither of us could detect any difference in the stability of our vans. So lets cut the crap about twin axles being more stable than single axles. Of all the factors that effect the stability of a van, the number of axles has probably the least effect.
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PeterD Nissan Navara D23 diesel auto, Spaceland pop-top Retired radio and electronics technician. NSW Central Coast.
Twins are less sensitive to weight distribution..
As said a well sett up single does the job just fine..
Larger vans or weight requires twin axle or more any way..
WE run a single axle van 17'6" weighs around the 2 tonne and ball weight 200 kgs have a weigh bridge ticket to reassure myself this is the weight it leaves home on a tour.
Tyres are rated at 1170 kg each, axle 3000 kg, chassis 2000 kg, towed by a 2500 car with max of 3500 and a 280 ball weight. Engineered to do the job.
I enjoy the road manners of this setup and with out load bars etc, but will switch to them on my replacement vehicle in the near future.
We have towed this van 20 000 ks of trouble free touring up any road, down any road with carefree touring.
Now the question asked the pros and cons.
If I was going anything longer I would need a 2 axle van to make it comply with transport rules and regulation.
Also the weigh allowance would help with a 2 axle van probably the biggest usable factor of all.
The other one would be having 4 brakes instead of 2 would help in that one off time but to date I have not questioned our braking ability.
Radar wrote:If I was going anything longer I would need a 2 axle van to make it comply with transport rules and regulation.
Also the weigh allowance would help with a 2 axle van probably the biggest usable factor of all.
The other one would be having 4 brakes instead of 2 would help in that one off time but to date I have not questioned our braking ability.
Your new van could have twin axles. It all depends on how much bigger you go. Beam axles go to a capacity of 2,000 kg but some independent suspensions go to a capacity of 2,300 kg. This will give you ATM capacities of from 2200 to 2500 kg or there a bouts. A lot of builders of the small to medium size off road style vans prefer to stick with single axles as they are more manoeuvrable in off road situations.
In this day and age you can order your van to be built to order to have greater than the "normal" 300 or 400 kg load capacity. There are a few builders that acknowledge we require larger capacities if our lifestyle includes extended travelling. I have seen a few vans at shows with more than the "normal" loading allowances in both single and twin axle categories. If a salesman will not negotiate higher loading capacities then you should consider voting with your feet.
With regards to braking, large capacity axles have large wheels (15" or bigger.) These have 12" brakes fitted in them. If you have twin axles then they are built with 1400 or 1600 kg axles. These are fitted with 10" brakes and 14" or less wheels. I think each system has been engineered to have excellent braking capacities.
-- Edited by PeterD on Friday 30th of May 2014 01:46:54 PM
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PeterD Nissan Navara D23 diesel auto, Spaceland pop-top Retired radio and electronics technician. NSW Central Coast.
From comments about common sense it's a bit hard to compare like for like I own a twenty one foot van with dual axles and have never seen a van this size or more importantly the same weight with a single axle but what I do know from having owned both single and double axle which I prefer for stability on the road and when backing into a site and the dual wins every time so you can only compare apples with apples when they are available I am also a great believer in common sense it works every time.
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A slightly different application, but still relevant -
My boat weighs 1500 kg fuelled up and ready to go, plus the trailer weight.
When I bought it new, it was delivered on a single axle trailer and I was told it was all legal.
I had to replace the wheel bearings every year - not regrease - replace with new bearings due to galling of the bearing surface.
There was always plenty of grease in there, and no water contamination.
I eventually fitted a second axle to the trailer, and in the past 7 years have not replaced the wheel bearings yet.
Check and repack every year, but no sign of wear.
The boat tows better with the dual axle, and is easier to control when reversing.
Also the brakes work better.
Only draw back is that it is harder to move around when disconnected.
PJK
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Now that food has replaced sex in my life -
I can't even get into my own pants!!!!!!
A slightly different application, but still relevant -
My boat weighs 1500 kg fuelled up and ready to go, plus the trailer weight. When I bought it new, it was delivered on a single axle trailer and I was told it was all legal. I had to replace the wheel bearings every year - not regrease - replace with new bearings due to galling of the bearing surface. There was always plenty of grease in there, and no water contamination.
This has very little to do with dual Vs single axle. It has everything to do with the correct axle loadings. A couple of things come to mind. One was that the rig was within limits as sold to you and you put extra loading in the boat. The other (and to my mind) was the trailer was not really big enough to carry the load. They have possibly underestimated the weight of the boat or not allowed for the motor weight.
I had a similar situation. The tare weight of my van was guestimated as being over 200 kg more than the weight as delivered. I also was replacing the bearings annually. After I had replaced 3 sets of bearings I put it over the weighbridge. The loaded van wheel weight was 250 kg more than the 1600 kg axle limit. I replaced the axle with aq 2t capacity on and have not replaced the bearings since 2006. It has demonstrated to me that a slight overload of the axle will result in a very reduced bearing life.
As I said, it has everything to do with axle loadings and not the number of them. It would possibly have been cheaper for you to replace the axle with a heavier one than add a second one.
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PeterD Nissan Navara D23 diesel auto, Spaceland pop-top Retired radio and electronics technician. NSW Central Coast.
A slightly different application, but still relevant -
My boat weighs 1500 kg fuelled up and ready to go, plus the trailer weight. When I bought it new, it was delivered on a single axle trailer and I was told it was all legal. I had to replace the wheel bearings every year - not regrease - replace with new bearings due to galling of the bearing surface. There was always plenty of grease in there, and no water contamination.
This has very little to do with dual Vs single axle. It has everything to do with the correct axle loadings. A couple of things come to mind. One was that the rig was within limits as sold to you and you put extra loading in the boat. The other (and to my mind) was the trailer was not really big enough to carry the load. They have possibly underestimated the weight of the boat or not allowed for the motor weight.
I had a similar situation. The tare weight of my van was guestimated as being over 200 kg more than the weight as delivered. I also was replacing the bearings annually. After I had replaced 3 sets of bearings I put it over the weighbridge. The loaded van wheel weight was 250 kg more than the 1600 kg axle limit. I replaced the axle with aq 2t capacity on and have not replaced the bearings since 2006. It has demonstrated to me that a slight overload of the axle will result in a very reduced bearing life.
As I said, it has everything to do with axle loadings and not the number of them. It would possibly have been cheaper for you to replace the axle with a heavier one than add a second one.
Peter, you are correct in that the problem I had was one of the load being very close to, or slightly exceeding, the rated axle load, but I would think that would also be the case with a 17 - 18' van, so same principles would apply.
I looked at a heavier single axle solution, but with boat trailers you try and keep wheel size down so that you need less water to launch and retrieve the boat. To go to a heavier axle I had to increase wheel diameter.
I am happy with what I did, and very happy with the result.
Having also towed single and dual axle caravans over the past 40 years, I also believe there is a point where it is just common sense to go to a dual axle arrangement.
Of course, this is only my opinion, backed up by my experience, and others are also welcome to their opinions.
Regards
Peter PK
-- Edited by PJK on Sunday 1st of June 2014 10:26:31 AM
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Now that food has replaced sex in my life -
I can't even get into my own pants!!!!!!
^^^Yes the same with car trailers.. ^^^
15" is about as large dia you want as loading side is too high..
Can run drop axle but you cant open the doors over the guards..
Equal and opposite reactions!!
