Aluminium Trailers – Torsion Arms vs Axle/Springs
Submitted by Darren253 on Thu, 2021-02-04 13:01
Considering my Aluminium Trailers options for the 2400 and wanted to gauge peoples opinion and experiences on Torsion arm vs Springs on Aluminium trailers?
From my consideration, Torsions arms have less moving and corroding parts and a lower C.O.G, however a torsion arm failure would be catastrophic. Torsion arms also offer no load sharing should you ever ride up a kerb for example (not that I have ever done that, honest )
What are your thoughts?
Browndog
Posts: 582
Date Joined: 10/04/12
Springs
Springs all the way for me. Every torsion arm type trailer I have ever owned has needed the axles to be replaced. Have just finished converting my dual axle cat trailer over to leaf springs, ride height is similar, but now easily replacebale down the track, much heavier duty. Price was around $1k more than just replacing the torsion axles. Trailer was steel, not ally, but don't think that would make much difference.
Cheers,
BD.
ranmar850
Posts: 2702
Date Joined: 12/08/12
Once you have seen the axle pull out ...
--torsion axles will do it, pull a tight U-turn when they are getting on and you can drag the whole stub/arm out. As well, they give no warning of failure. They have the advantage of a lower ride height than springs, no cosmetic rust...use multi-leaf springs, you break one on the road, you can get by with various bodges. Have a rubber torsion fail, what can you do?
The load sharing thing is important, too, IMO. Proper rocker load sharing rides much better than individuals. You do seem to see a lot more torsions on ali trailers
Rob H
Posts: 5784
Date Joined: 18/01/12
Axles
Everything mentioned above is absolutely true.
Having said that I have gone with 2500kg torsions on the new trailer I am building now, my first foray into torsion.
Points of note, and my observations
During the boat (and trailer) import boom 10 years back, I noticed that many trailer importers (and many private imports as well) are actually not legally rated correct in Aus as the US afaik does not have the 120% rule.
It is quite easily noticable, the US standard 3500 pound axle uses Ford 5 stud hubs, 10" discs and 14" rims.
3500 = 1590kg x 2 @120% is only around 2700kg-many are rated here as 3.5T. I guess mainly because here they have just used the US, or the company importing can simply tag them as whatever they want as manufacturers only need to get something like 1 in 20 (or 50?) actually inspected.
This may also be contributing to the numbers of failures people observe given our roads are generally narrower and rougher than US
Long post I know sorry
Give a man a mask, and he'll show you his true face...
The older you get the more you realize that no one has a f++king clue what they're doing.
Everyone's just winging it.
Darren253
Posts: 570
Date Joined: 23/07/16
Cheers
Great info Rob No "sorry" required
ranmar850
Posts: 2702
Date Joined: 12/08/12
Yes, what Darren said
^^^^ I'd never actually considered the fact that the cross axles on torsions also act as a structural member, instead of unsprung weight. And I knew I'd be doing a lot of really bad roads with this--Ningaloo station roads, Tamala when it is due for a grading ---so it was a no-brainer.
Dustymongrel
Posts: 13
Date Joined: 05/03/11
Parabolic Springs
Hey mate, have you had a look at the parabolic springs. Had some fitted to my hilux and the ride is great. I presume they make them for trailers etc. Look like they would be easier to wash the salt off too. Just a it more initial outlay.
sea-kem
Posts: 14931
Date Joined: 30/11/09
I actually put parabolics on
I actually put parabolics on my boat trailer last year and were cheaper than the 9 leaf spring set. When speaking to the fella at Martins he said they were initially getting them galvanised and had a couple returned broken as galavanising brittlises the steel. Since they left them black steel they'd had no returns. Good for crrosion control as leaves for salt water to ingress.
I've had the boat up to Gnaraloo and up and down the track to the bay for a week with no problems, also the 70km's in and out. That in my opinion is a good test. I do carry a spare though.
Love the West!
ranmar850
Posts: 2702
Date Joined: 12/08/12
I'm really wary of Parabolics nowadays.
After a catastrophic failure on the Ningaloo station road. It's all very well to carry a spare spring , but you had better carry a spare axle as well. My 600 Quintrex CC had tandem parabolics, which of course are non-load share. On the way home one year, about 10.30 am, one of the parabolics ( rear axle) snapped about halfway out to the highway. You have absolutely no backup with parabolics--they snap through the locating pin hole , then you have nothing securing the axle on that side. So the wheel/tyre assembly on that side goes back with great force, bending the axle and doing other damage such as ripping the tyre open on any hardware it encounters and taking your mudguard with it.
This all happened to me, I was taking it steady, 15km to the bitumen, then bang. Disaster. What a mess. I won't go into details on the fix, but was lucky enough to pick up spares in Exmouth . After leaving the boat on the side of the road. We got back to Kalbarri about 6.30 next morning. And I have seen it happen to at least one other vehicle on that track. I donated a set to Phil next year to put in the spares bin, and still have some lying around here, if anyone wants them.
yes, galvanising springs certainly can cause embrittlement. My current set, just on 3yo, was on the Easytow trailer I ordered with the boat--appear to be galvanised, but may be some other finish, no rust.
Rob H
Posts: 5784
Date Joined: 18/01/12
The last trailer I built 10
The last trailer I built 10 years back, Martins were out of galvanised 7 leaf so I bought from either Bigman or Huntsman through Ebay.
The "galvanising" had disappeared after about 6 months and when I queried them they said "oh we dont galvanise them, its Dacromet".
I suspect it was more likely silver spray paint...
Just recently though I saw a mates springs, he coats them with Soft Seal which is for protecting machined surfaces.
Looks much like new...
Give a man a mask, and he'll show you his true face...
The older you get the more you realize that no one has a f++king clue what they're doing.
Everyone's just winging it.
Cruise Control
Posts: 973
Date Joined: 03/11/10
Had torsion arms on my 685
Had torsion arms on my 685 Cruise Craft trailer for 7 years. Towed back and forth to Coral Bay every year (almost) without any issues and all over Perth/Mandurah. I know that Ace Trailers ensured that the torsion bars were compliant with the 3.5t capacity.
Preferred torsion suspension over springs for smoother and quieter ride but then I was very gentle with my gear when I towed.
Rob H
Posts: 5784
Date Joined: 18/01/12
.
Hey Bruce, yeah issue was always with imported trailers that were already tagged in the US.
I first saw this at a Perth manufacturer (horse trailers I think) who was importing US trailers.
I had a look at them to buy and asked "what are they rated at?"
Answer was "We can do it to whatever you want".
Give a man a mask, and he'll show you his true face...
The older you get the more you realize that no one has a f++king clue what they're doing.
Everyone's just winging it.
ab1961
Posts: 70
Date Joined: 05/12/12
New Trailer
I have just had a new trailer built to replace a tri-axle cat trailer with torsion axles, we went to a dual axle with leaf springs and landcruiser hubs, I will never have torsion axles again, they are impossible to repair.