Twin axle vs single axle

[CPH]

I've been thinking of getting a newer van for a while and wouldn't mind getting a bigger twin axle van.

My current van is an old elddis and weighs in at about 1080KG fully laden. Max towing capacity of the car is 1600KG but I want to avoid going as high as that if I can help it, although I have my eye on a Swift Conqueror which just tops that number if it's loaded to the max.

However, I have a query. My single axle van tows really well, the car will happily pull it all day long and barely breaks a sweat. A couple of weeks ago I hired a twin axle box trailer to transport some of my girlfriends furniture from Peterborough to South Wales. The empty weight of the trailer was only 600KG but the car hated it and struggled to maintain 60 MPH on the motorway, overtaking and inclines were horrible.

Luckily my car is chipped so I stopped at a services and turned the chip on (I only normally use it for towing as I find the power delivery a bit too aggressive for normal use) while at the same time checking the brakes on the trailer in case they were binding, the hubs were barely warm so I assume it was all ok.

With the chip on it was plain sailing once again.

I was quite surprised that the car struggled so much without the extra power from the chip though. Is this because of the extra rolling resistance from the twin axle setup? Would I experience the same issue from a twin axle caravan?

I've had a fair bit of towing experience but this was the first time I've pulled anything twin axle and was really surprised that the car struggled with it.

[panddhicks]

I am surprised that you had problems towing a twin axle box trailer. I can only think that the problem may have been caused by wind resistance. I have a 2ltr1995 850 petrol Volvo towing a twin axle dropside trailer. Less wind resistance with the dropside than a box. My trailer unladen weighs 500kgs. Maximum loaded weight 2000kgs. I normally load it to around 1500kgs maximum and I have not had problems negotiating the wolds/hills in my area. I find twin axle trailers better for towing than the single one.
Best of luck
Regards
Paul

[mike95]

I have had and towed both over the years and our twin axles have been much easier to tow as they are more stable. They also tend to have lower profile tyres so slightly lowering the centre of gravity.

All things being equal it would be the twin axle for me. However, in recent years they have grown in size and weight. A few years ago our Bailey Unicorn would have been on a twin axle but now just single.

Consequently I think you might struggle to find a twin axle below your 1600 kg weight limit.

The other thing that you need to watch out for is that some campsites on the continent will not take twin axles..

Hope this helps.

Good luck.

Mike

[c_lee]

Regarding a twin axle caravan there are several considerations to keep in mind - some of which you will probably know already:

1/. If it doesn't have a motor mover fitted they are more difficult to maneuver manually especially regarding rotating it. Much bigger turning circle - you can rotate a single on its axle. Twin axle motor movers are more expensive to fit too if it doesn't already have one.

2/. There are many large caravans these days that are in single axle format that many years ago would have been offered as a twin for a caravan of the same size or weight - I think some manufactures at one time played on the 'more is better' mentality when it wasn't really needed - and charged the extra appropriately for the FAD.

3/. A twin axle van has the, not inconsequential, extra weight of the second axle, more complex braking and extra servicing cost. If a twin axle is not essential due to size or weight, IMO that extra weight would be better used as additional payload or reduced car towing load to suit the likely lower overall permissible weight.

4/. Leveling of a twin axle van on site is not as simple as leveling a single axle.

I think twin axles do offer some advantages in some cases, but IMO they are more likely to be overridden by the advantages of single axle unless for a really big ( heavy ) van which would be over your 1,600KG limit anyway.

I have a V70 TDI too limited to 1,600 KG.

HTH - Colin

[CPH]

Hi Paul,

Thanks for your experience with twin axle trailers. I'm surprised it was a pig too and given your reassurance that it shouldn't have been a problem I'm wondering whether the pump timing belt has stretched and the lack of towing power is due to less than optimal injection timing, will have it checked out soon.

Mike,

I didn't know that some continental sites had restrictions on twin axle vans, thanks for the heads up. We actually quite fancy doing a spot of touring in Europe so will take that into consideration and maybe reevaluate whether we need a twin or not.

I have generally noticed that newer vans seem to be bigger and heavier than a lot of the older ones out there. There are some twin axles that I would really like, I do like the Swift Conqueror 580, the ones in my budget top the scales at 1619KG fully loaded and the generation earlier at 1600KG fully laden. The perfect van would be the Avondale 630/6 which despite being a big van weighs in at 1450KG at the limit, I believe. That's way out of my budget at the minute though, a bit too new 😕

I don't pack loads of stuff when going away so wouldn't expect to get anywhere near the limit on any van, although an over zealous copper might take exception to towing a van with a limit that exceeds the car's legal limit, and the heavier bulkier stuff I put in the boot for extra stability and so when we get to site there's less to take out the van before it can be used for tired kids and emergency bathroom breaks etc so would be keeping the van pretty light really. The car has beefed up rear suspension so I'm not worried about loading weight in the back.

Colin,

Thanks for the pointers. I know twin axles are more difficult to manoeuvre and manhandle. I've never used a motor mover, I just struggle on moving it with the car, I'm getting better at it too 😂

I wasn't aware that levelling a twin axle was an issue, but it stands to reason I suppose.

Many thanks guys for your help, much appreciated.

Chris

[pagan8c]

I have a twin axle Lunar 640 which has an mtlp of 1795kgs but I have the XC 70 MY13 215 engine so no problem towing it .I don't find the twin difficult to level as I carry some bits of decking wood which I can double or treble up to raise the downside section.I do have all wheel movers because it is to heavy to move by hand.You can also buy a type of airbag system which will level up twins easily.I like my twin and it is the first 1 I have had .I got this because of the layout of the van but it would not have bothered me to get another single axle if the layout had been what I wanted .I find reversing the twin onto my drive is better than a single because it comes round more gradual where as you know a single gets to a point then seems to move round a lot quicker.Other than that I would have a single again any time even if it was quite long.

[Steamdrivenandy]

One of the things that aggravates me with Lunar twin axles is that they extend the van compared to the singles but don't use the extra length to make the beds longer. So you still end up with a maximum bed length of 6ft 2ins (6ft 3ins for a double) which isn't helpful to anyone over 6ft tall.

[heyskull]

I have an old 1990s Bessacarr 500GLD which is a twin axle.
Thiis I take of site twice a year and probably only tow for about 600 miles.
It is very stable and I can probably agree that twin axles were a fad of sorts.

But in my opinion the biggest advantage (especially with it being a relativley lightweight for size) is more tyres with almost half the air pressure of a single axle caravan.
Thus meaning less likely to overheat and blow a tyre and if one does go pop double the chance of the van still being in one piece.

SC

[mordred1973]

As a youngster (!) I towed my parents caravans, probably more than my dad, he tended to use the phrase "why have a dog and bark myself"

I have thuse towed a 1975 Monza 1000, a 1982 Ace Harmony, 1992 Ace Herald, 2000 ABI Dales 520 (seem to remember they were avail in single or twin on same size caravan).

Since starting caravaning with my family, I was mildly apprehensive over getting a 2010 Bailey Pegasus 646, due to a) overall size b) the weight and c) the twin axle setup. My concerns were unfounded.

Stability is perfect, despite towing at a 92% ratio, manoeuvring with the car is as already mentioned easier than the single axle's towed before. The downside is that it is almost impossible to move by hand, ours had a motor-mover fitted when we purchased it (only a 2 wheel drive one) which works brilliantly, although the dearer 4wheel drive ones turn much tighter.

Having said all of that, we were adjacent to a new Adria on site recently, which was the same overall size and after googling, the same overall weight as ours, all on a single axle.

[sunshinetours]

Originally Posted by mordred1973

As a youngster (!) I towed my parents caravans, probably more than my dad, he tended to use the phrase "why have a dog and bark myself"

I have thuse towed a 1975 Monza 1000, a 1982 Ace Harmony, 1992 Ace Herald, 2000 ABI Dales 520 (seem to remember they were avail in single or twin on same size caravan).

Since starting caravaning with my family, I was mildly apprehensive over getting a 2010 Bailey Pegasus 646, due to a) overall size b) the weight and c) the twin axle setup. My concerns were unfounded.

Stability is perfect, despite towing at a 92% ratio, manoeuvring with the car is as already mentioned easier than the single axle's towed before. The downside is that it is almost impossible to move by hand, ours had a motor-mover fitted when we purchased it (only a 2 wheel drive one) which works brilliantly, although the dearer 4wheel drive ones turn much tighter.

Having said all of that, we were adjacent to a new Adria on site recently, which was the same overall size and after googling, the same overall weight as ours, all on a single axle.

The Adria's (and other Euro makes) are on a larger longer chassis so have also a longer A frame promoting a more stable tow and allowing much higher weights than previously to be on a single axle. Some of the Adria's you are referring to are about 8.3m long on a single axle and 1800kg+ !