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jmpc Gate Opener
Joined: 27 Oct 2009 Odometer: 29
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Posted: Thu Oct 29, 2009 8:42 am Post subject: Trailer suspension, axle configurations & weights?
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Hi all,
having just completed a self build trailer I am interested in hearing from anyone with experience of trailer suspension.
Which system is best - is indespension popular because it is easier for the manufactures to use, or is it actually better in some cases?
Leaf spring vs trailing arm - pros and cons of each please.
Single axle or tandem, and if tandem, close coupled?
Trailer wheel track, how important is it to match the track of the vehicle? Does it really matter that much, are there any advantages to it NOT matching the vehicle´s track.
And weight, how much is too heavy?
__________________________________ all the best
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Jimmy Just got MTs
Joined: 01 Nov 2006 Odometer: 307 Location: Wirral, Cheshire
1992 Toyota Landcruiser
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Posted: Thu Oct 29, 2009 6:41 pm Post subject: Re: Trailer suspension, axle configurations & weights?
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jmpc wrote: | Which system is best - is indespension popular because it is easier for the manufactures to use, or is it actually better in some cases? |
I have had problems before with indespension units collapsing. I would never personally use them on an off road trailer build. They seem to have a much shorter life than other systems. If it was me, I would use leaf springs because they are simple to use and easy to "emergency bodge" back together should they break.
Quote: | Trailer wheel track, how important is it to match the track of the vehicle? Does it really matter that much, are there any advantages to it NOT matching the vehicle´s track. |
There are advantages to having a narrower track than the vehicle, i.e the trailer will closer follow the vehicles track when turning a tight corner rather than cutting it. Having the axle closer to the towing vehicle also helps with this. Of course, the ultimate track has to be a compromise between stability and manueverability, and the type of terrains it's most likely to encounter.
just my 2p
__________________________________ Reality is a nice place to visit, but I wouldn't want to live there |
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trailer guy Articulating
Joined: 19 Feb 2009 Odometer: 787 Location: Hampshire
1994 Land Rover 110
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Posted: Sun Nov 08, 2009 10:34 pm Post subject:
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Hi JMPC,
As Jimmy states, there's pros and cons to all suspension systems. The Indespension type (Indespension's actually a brand name derived from 'independent suspension system') is a rubber torsion system that works on compression. They're also manufactured by Peak, Al-ko, Meredith & Eyre etc. The good thing about this type is the road manners - smooth, quiet and responsive to the odd bump. The not so great side being that they're not designed to take severe abuse.
Leaf springs, comparatively, are fairly agricultural and pretty robust. They can be fixed easily if you're stuck in the middle of nowhere.
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trailer guy Articulating
Joined: 19 Feb 2009 Odometer: 787 Location: Hampshire
1994 Land Rover 110
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Posted: Sun Nov 08, 2009 10:57 pm Post subject:
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Sorry, had to break off then!
On a negative side, leaf springs (used by the likes of Ifor Williams and the majority of USA manufacturers) are often noisey and quite often require loading to near capacity before they give a decent ride.
Personally I wouldn't build an off-road trailer to more than 750kg GVW. This would still give a load capacity of 500kg (depending on the weight of your trailer). You probably wouldn't want to drag a stuck trailer weighing more than 750kg (three quarters of a ton) if it got stuck somewhere. You'd end up with either a burnt out clutch or, if you were trying to shove it by hand, a popped testicle! Not only that, it means you don't require brakes - another initial outlay expense and something else to go wrong.
Mine's got the axle pretty near the back, for better access and egress approach angles. It's also the same width track as the towing vehicle, so it doesn't have to cut it's own track. Also, the pcd (pitch circle diameter - stud pattern) is the same as the tow vehicle, so the wheels are interchangeable should the need arise!
Your self-build trailer, which looks excellent by the way, doesn't look like the sort of bit of kit you'd want to tow too far off the beaten track? Are you planning on building another? What are you looking to do with it?
Good luck planning!
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jmpc Gate Opener
Joined: 27 Oct 2009 Odometer: 29
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Posted: Sat Nov 14, 2009 12:29 pm Post subject: Re: Trailer suspension, axle configurations & weights?
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Jimmy wrote: | jmpc wrote: | Which system is best - is indespension popular because it is easier for the manufactures to use, or is it actually better in some cases? |
I have had problems before with indespension units collapsing. I would never personally use them on an off road trailer build. They seem to have a much shorter life than other systems. If it was me, I would use leaf springs because they are simple to use and easy to "emergency bodge" back together should they break.
Quote: | Trailer wheel track, how important is it to match the track of the vehicle? Does it really matter that much, are there any advantages to it NOT matching the vehicle´s track. |
There are advantages to having a narrower track than the vehicle, i.e the trailer will closer follow the vehicles track when turning a tight corner rather than cutting it. Having the axle closer to the towing vehicle also helps with this. Of course, the ultimate track has to be a compromise between stability and manueverability, and the type of terrains it's most likely to encounter.
just my 2p |
Thanks for the reply Jimmy, and I am sure I´ll end up greeing with you on the indespension suspension, not that I don´t agree already, but I have to test it anyway now that I have it,
__________________________________ all the best
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jmpc Gate Opener
Joined: 27 Oct 2009 Odometer: 29
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Posted: Sat Nov 14, 2009 12:54 pm Post subject:
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trailer guy wrote: | Sorry, had to break off then!
On a negative side, leaf springs (used by the likes of Ifor Williams and the majority of USA manufacturers) are often noisey and quite often require loading to near capacity before they give a decent ride.
Personally I wouldn't build an off-road trailer to more than 750kg GVW. This would still give a load capacity of 500kg (depending on the weight of your trailer). You probably wouldn't want to drag a stuck trailer weighing more than 750kg (three quarters of a ton) if it got stuck somewhere. You'd end up with either a burnt out clutch or, if you were trying to shove it by hand, a popped testicle! Not only that, it means you don't require brakes - another initial outlay expense and something else to go wrong.
Mine's got the axle pretty near the back, for better access and egress approach angles. It's also the same width track as the towing vehicle, so it doesn't have to cut it's own track. Also, the pcd (pitch circle diameter - stud pattern) is the same as the tow vehicle, so the wheels are interchangeable should the need arise!
Your self-build trailer, which looks excellent by the way, doesn't look like the sort of bit of kit you'd want to tow too far off the beaten track? Are you planning on building another? What are you looking to do with it?
Good luck planning! |
Hi Trailer Guy, thanks for the reply. .. yes, I am intending to build another, this one was always going to be a 'prototype`as I knew I was going to make a lot of mistakes. Now, more than ever, that I can see what I should have done differently its impossible not to want to build another, improved version.
This one currently weighs 900kg, net, and will weigh up to 1,400kg when fully loaded.
The improved version will be built using lighter materials, so should stay under the 750kg mark net.
You´re right of course, this is not for extreme offroading, but mainly being into overlanding I find that the majority of offroading I do is normally on tracks and paths that, while too hard for a normal car for hours on end, are not that challenging at all for a 4x4, especially if ones takes it easy.
Having said that though, I have made some pretty impressive assents and descents on some mountain paths that have required low gears in low range all the way, and I have not had any trouble.
But as I´m sure you know, it's often the case that what looks super challenging often isn't, and what looks easy can quickly become super challenging, like getting completely stuck at the bottom of a grassy meadow because of a slight incline and a bit of morning dew!
The next version will have a leaf spring or a trailing arm set up, the later currently being my favourite choice, but here I am open to persuasion.
__________________________________ all the best
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mike. Mud Obsessed
Joined: 03 Nov 2005 Odometer: 4010 Location: wirral
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Posted: Sat Nov 14, 2009 9:30 pm Post subject:
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after seeing a cross section of an indespension unit its not hard to see why it broke, this one let go because of a little bit of corrosion and a gentle speed bump. some are stronger than others but i wouldn't like to rely on them off the tarmac. the fact you have a twin axle setup will help iron out potholes though.
do you think you could fit shock absorbers to it? would help them take a clobbering.
the best aussie units have coils, the really expensive ones have wishbones!
i'd like to make an offroad trailer when i've finished my project, my plan is to use front hubs off an sj (larger bearings and better seals than trailer hubs) in a portal configuration to give decent clearance. using short springs and radius arms.
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Roger Mud Obsessed
Joined: 25 Feb 2008 Odometer: 2050 Location: Redditch Worcestershire
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Posted: Sun Nov 15, 2009 5:20 pm Post subject:
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jmpc wrote: | trailer guy wrote: | Sorry, had to break off then!
On a negative side, leaf springs (used by the likes of Ifor Williams and the majority of USA manufacturers) are often noisey and quite often require loading to near capacity before they give a decent ride.
Personally I wouldn't build an off-road trailer to more than 750kg GVW. This would still give a load capacity of 500kg (depending on the weight of your trailer). You probably wouldn't want to drag a stuck trailer weighing more than 750kg (three quarters of a ton) if it got stuck somewhere. You'd end up with either a burnt out clutch or, if you were trying to shove it by hand, a popped testicle! Not only that, it means you don't require brakes - another initial outlay expense and something else to go wrong.
Mine's got the axle pretty near the back, for better access and egress approach angles. It's also the same width track as the towing vehicle, so it doesn't have to cut it's own track. Also, the pcd (pitch circle diameter - stud pattern) is the same as the tow vehicle, so the wheels are interchangeable should the need arise!
Your self-build trailer, which looks excellent by the way, doesn't look like the sort of bit of kit you'd want to tow too far off the beaten track? Are you planning on building another? What are you looking to do with it?
Good luck planning! |
Hi Trailer Guy, thanks for the reply. .. yes, I am intending to build another, this one was always going to be a 'prototype`as I knew I was going to make a lot of mistakes. Now, more than ever, that I can see what I should have done differently its impossible not to want to build another, improved version.
This one currently weighs 900kg, net, and will weigh up to 1,400kg when fully loaded.
The improved version will be built using lighter materials, so should stay under the 750kg mark net.
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I am not certain if your use of the 750kg weight is just coincidental, but if you do not have trailer brakes then the 750kg is the gross weight allowed.
Roger
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trailer guy Articulating
Joined: 19 Feb 2009 Odometer: 787 Location: Hampshire
1994 Land Rover 110
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Posted: Sun Nov 15, 2009 9:29 pm Post subject:
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No coincidence there! That's why I've built mine to 750kg GVW.
It means I don't have the expense, and possible failure, of a braking system. It shouldn't way more than 250kg (I've made the top out of ally chequer plate), giving me a payload of 500kg.
I was honest with myself and admitted I wouldn't be rock-crawling with it and half a ton was more than enough gear to drag behind me.
I've been in the trailer game a while so put a bit of thought in to it before commencing build.
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jmpc Gate Opener
Joined: 27 Oct 2009 Odometer: 29
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Posted: Mon Nov 16, 2009 1:03 pm Post subject:
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trailer guy wrote: | No coincidence there! That's why I've built mine to 750kg GVW.
It means I don't have the expense, and possible failure, of a braking system. It shouldn't way more than 250kg (I've made the top out of ally chequer plate), giving me a payload of 500kg.
I was honest with myself and admitted I wouldn't be rock-crawling with it and half a ton was more than enough gear to drag behind me.
I've been in the trailer game a while so put a bit of thought in to it before commencing build. |
Have you got any pics trailer guy?
__________________________________ all the best
JMPC |
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jmpc Gate Opener
Joined: 27 Oct 2009 Odometer: 29
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Posted: Mon Nov 16, 2009 1:09 pm Post subject:
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Roger wrote: | jmpc wrote: | trailer guy wrote: | Sorry, had to break off then!
On a negative side, leaf springs (used by the likes of Ifor Williams and the majority of USA manufacturers) are often noisey and quite often require loading to near capacity before they give a decent ride.
Personally I wouldn't build an off-road trailer to more than 750kg GVW. This would still give a load capacity of 500kg (depending on the weight of your trailer). You probably wouldn't want to drag a stuck trailer weighing more than 750kg (three quarters of a ton) if it got stuck somewhere. You'd end up with either a burnt out clutch or, if you were trying to shove it by hand, a popped testicle! Not only that, it means you don't require brakes - another initial outlay expense and something else to go wrong.
Mine's got the axle pretty near the back, for better access and egress approach angles. It's also the same width track as the towing vehicle, so it doesn't have to cut it's own track. Also, the pcd (pitch circle diameter - stud pattern) is the same as the tow vehicle, so the wheels are interchangeable should the need arise!
Your self-build trailer, which looks excellent by the way, doesn't look like the sort of bit of kit you'd want to tow too far off the beaten track? Are you planning on building another? What are you looking to do with it?
Good luck planning! |
Hi Trailer Guy, thanks for the reply. .. yes, I am intending to build another, this one was always going to be a 'prototype`as I knew I was going to make a lot of mistakes. Now, more than ever, that I can see what I should have done differently its impossible not to want to build another, improved version.
This one currently weighs 900kg, net, and will weigh up to 1,400kg when fully loaded.
The improved version will be built using lighter materials, so should stay under the 750kg mark net.
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I am not certain if your use of the 750kg weight is just coincidental, but if you do not have trailer brakes then the 750kg is the gross weight allowed.
Roger |
Roger,
a question for both you and trailer guy - aside from the law, at which weight would you feel comfortable towing without breaks with your set up?
I have a 5 door Ptrol, which is heavy at about 2,400 kg, so I guess (not that I have ever tried becasue I always seam to be towing stuff that weighs in above a ton, with breaks) that 750kg without breaks , behind would hardly notice, but is that really the case? If mechanical problems wern't an issue would you be inclined to put breaks on anyway?
__________________________________ all the best
JMPC |
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jmpc Gate Opener
Joined: 27 Oct 2009 Odometer: 29
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Posted: Mon Nov 16, 2009 1:17 pm Post subject:
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mike. wrote: | after seeing a cross section of an indespension unit its not hard to see why it broke, this one let go because of a little bit of corrosion and a gentle speed bump. some are stronger than others but i wouldn't like to rely on them off the tarmac. the fact you have a twin axle setup will help iron out potholes though.
do you think you could fit shock absorbers to it? would help them take a clobbering.
the best aussie units have coils, the really expensive ones have wishbones!
i'd like to make an offroad trailer when i've finished my project, my plan is to use front hubs off an sj (larger bearings and better seals than trailer hubs) in a portal configuration to give decent clearance. using short springs and radius arms. |
Mike, yes could put shocks on I suppose, thanks for the idea! Your suspension idea with a portal axle sounds thought through. What are radius arms?
__________________________________ all the best
JMPC |
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trailer guy Articulating
Joined: 19 Feb 2009 Odometer: 787 Location: Hampshire
1994 Land Rover 110
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Posted: Mon Nov 16, 2009 8:17 pm Post subject:
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jmpc wrote: | trailer guy wrote: | No coincidence there! That's why I've built mine to 750kg GVW.
It means I don't have the expense, and possible failure, of a braking system. It shouldn't way more than 250kg (I've made the top out of ally chequer plate), giving me a payload of 500kg.
I was honest with myself and admitted I wouldn't be rock-crawling with it and half a ton was more than enough gear to drag behind me.
I've been in the trailer game a while so put a bit of thought in to it before commencing build. |
Have you got any pics trailer guy? |
Thread here, in this section:
http://forum.difflock.com/viewtopic.php?t=44044
__________________________________ www.compasstrailers.com |
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trailer guy Articulating
Joined: 19 Feb 2009 Odometer: 787 Location: Hampshire
1994 Land Rover 110
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Posted: Mon Nov 16, 2009 8:36 pm Post subject:
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jmpc wrote: | Roger wrote: | jmpc wrote: | trailer guy wrote: | Sorry, had to break off then!
On a negative side, leaf springs (used by the likes of Ifor Williams and the majority of USA manufacturers) are often noisey and quite often require loading to near capacity before they give a decent ride.
Personally I wouldn't build an off-road trailer to more than 750kg GVW. This would still give a load capacity of 500kg (depending on the weight of your trailer). You probably wouldn't want to drag a stuck trailer weighing more than 750kg (three quarters of a ton) if it got stuck somewhere. You'd end up with either a burnt out clutch or, if you were trying to shove it by hand, a popped testicle! Not only that, it means you don't require brakes - another initial outlay expense and something else to go wrong.
Mine's got the axle pretty near the back, for better access and egress approach angles. It's also the same width track as the towing vehicle, so it doesn't have to cut it's own track. Also, the pcd (pitch circle diameter - stud pattern) is the same as the tow vehicle, so the wheels are interchangeable should the need arise!
Your self-build trailer, which looks excellent by the way, doesn't look like the sort of bit of kit you'd want to tow too far off the beaten track? Are you planning on building another? What are you looking to do with it?
Good luck planning! |
Hi Trailer Guy, thanks for the reply. .. yes, I am intending to build another, this one was always going to be a 'prototype`as I knew I was going to make a lot of mistakes. Now, more than ever, that I can see what I should have done differently its impossible not to want to build another, improved version.
This one currently weighs 900kg, net, and will weigh up to 1,400kg when fully loaded.
The improved version will be built using lighter materials, so should stay under the 750kg mark net.
|
I am not certain if your use of the 750kg weight is just coincidental, but if you do not have trailer brakes then the 750kg is the gross weight allowed.
Roger |
Roger,
a question for both you and trailer guy - aside from the law, at which weight would you feel comfortable towing without breaks with your set up?
I have a 5 door Ptrol, which is heavy at about 2,400 kg, so I guess (not that I have ever tried becasue I always seam to be towing stuff that weighs in above a ton, with breaks) that 750kg without breaks , behind would hardly notice, but is that really the case? If mechanical problems wern't an issue would you be inclined to put breaks on anyway? |
You'd be surprised. I've dragged just under 5 tons (I know, I know, you don't need to say anything!... it was private property so no laws broken) with the shogun (3.5 v6 24v) and it coped amazingly well. Didn't need to take it out of 2WD. It was obviously braked, but the wagon coped very well all the same - even reversing the load up an incline!
I dare say you'd hardly notice 750kg, braked or not, behind the Patrol. Even 'law aside', personally I'm happy that 750kg is about right for trundling around without any brakes. Don't forget, ridiculously, the 750kg GVW, unbraked, law applies to Fiestas and LWB Patrols the same!
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jmpc Gate Opener
Joined: 27 Oct 2009 Odometer: 29
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Posted: Mon Nov 16, 2009 8:52 pm Post subject:
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Trailer guy
took a look at your self build, nice work! I see you've opted for indespension system, are you going to take it off road as I am mine?
__________________________________ all the best
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trailer guy Articulating
Joined: 19 Feb 2009 Odometer: 787 Location: Hampshire
1994 Land Rover 110
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Posted: Mon Nov 16, 2009 10:55 pm Post subject:
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Yes, probably give it a bit of a trundle out (still not finished - work gets in the way of so much fun, doesn't it?!) when I'm happy it's pretty much there.
The Indespension axle was used because it's a prototype and unlikely to get rock-crawled, plus the axle was built to my spec (size, weight capacity -1000kg-, PCD etc) and was FOC, so a bit of a no-brainer!
I'll give it a bit of a hard time and see how it goes!
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