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car trailer suspension?
Posted: Fri May 22, 2009 7:52 pm
by Renton
i'm looking into car trailers to tow my comp truck. just after pro's and con's for rigid versus leaf suspension?
there's quite a few rigids out there for sale, but am worried that it will be too much strain on the trailer chassis or the tow hitch with the amount of weight on it.
anyone have experience with either options?
.
Posted: Fri May 22, 2009 8:19 pm
by lukes4x4
just built my trailer . cost me $4500 in materials. rated but at 2500kg gross and weighs 640kg so legally can tow 1860kg . it has rocker setup as the springs to get the rating. it tows excelent and only has approximatly 100kg ball weight with the buggy on it. i have electric 10 inch drum brakes on both axles, and a breakaway unit. led lights etc. any box trailer though that is gonna be rated at over 2000kg gross needs to be bluesliped at a heavy vehcile blueslip station. if i was to do it again i would go 60mm wide springs rather than the 45mm so i could rate it at 3200kg.
cheers lukey
Posted: Fri May 22, 2009 8:21 pm
by Slunnie
I've not towed with a rigid, but my work produces quite a few trailers each year for HSC projects.
The rigids dont load share if the ball height isn't correct - the ball height must be correct. The rigids do however have lower deck heights.
Posted: Fri May 22, 2009 9:31 pm
by Eddy
Rigid are garbage ... REALLY ...
Shake themselves to bits, unless they're built heavy, and then you're overloaded as soon as you throw your toolbox aboard.
You need a proper load sharing rocker leaf spring setup.
Easier and safer.
Posted: Fri May 22, 2009 11:17 pm
by sudso
I made a car trailer for a farmer using 2nd hand independant suspension he sourced from a caravan. Basically an A arm set up. Rides smooth as with or without a car on.
Posted: Fri May 22, 2009 11:53 pm
by Corgie Carrier
I have friends in speedway and they swear by rigids.
BUT only if they are always loaded, unloaded they bounce all over the road.
So if you are just towing your rig to comps and home I would suggest a rigid.
If you are unsure, track down a rigid you can borrow and put your rig on it and try it out.
Posted: Sat May 23, 2009 9:01 am
by Shadow
is rigid where the leaf spring is upside down (to normal) Bolted(clamped?) to the chassis in the middle, and each end of the spring attaches to an axle?
Posted: Sat May 23, 2009 9:37 am
by Dozoor
A couple of things to Keep in mind for our sport ,
The roads to a lot of comps are ruff as , so suspension is a plus.
Often it may be dirt and steep , which can turn to Mud and steep
so electric brakes are a must , if you run out of traction going up
with overide brakes on the trailer will drag you all the way back to
Bottom.
Posted: Sat May 23, 2009 11:10 am
by ausyota
Dozoor wrote:electric brakes are a must , if you run out of traction going up
with overide brakes on the trailer will drag you all the way back to
Bottom.
Good point. I hadnt though of that.
I am going to be buying and modifying or building a trailer soon, I was tossing up what brakes to put on.
Posted: Sat May 23, 2009 12:59 pm
by tweak'e
to be honest i haven't really had that problem. usually you lose drive traction before you loose braking traction. also if tow vechile goes back would it locks the trailer brakes on.
however electric brakes certainly have an advantage in helping control the trailer.
i'm not up on your guys rules but i think you need electrics for that weight class anyway.
one thing i have found the hard way is trailer brakes are pointless if the wheels don't have traction. your better off to go 4 wheel brakes on the trailer. especially with override brakes. if the trailer starts sliding it forces more braking on which simply locks the wheels up.
suspension, tandem leafs (load sharing) with shocks.
typically slipper springs because they are a bit lower than full rocker. but rocker is more comfortable.
i have found that the banging/boucing when unloaded is reduced with shocks installed. also lowering tire pressure helps to.
don't forget to allow for you wheels. you will want decent sized tires for offroad. unfortunaly that can mean a very wide trailer or a flat deck trailer.
Posted: Sat May 23, 2009 1:09 pm
by Slunnie
tweak'e wrote:suspension, tandem leafs (load sharing) with shocks.
typically slipper springs because they are a bit lower than full rocker. but rocker is more comfortable.
i have found that the banging/boucing when unloaded is reduced with shocks installed. also lowering tire pressure helps to.
Yep, I'm pretty sure we have done setups with shackles on the rocker though, so you can have shackles and maintain a lower ride height also.
Posted: Sat May 23, 2009 1:40 pm
by Corgie Carrier
Shadow wrote:is rigid where the leaf spring is upside down (to normal) Bolted(clamped?) to the chassis in the middle, and each end of the spring attaches to an axle?
Rigid is where the trailer frame is welded to the axles, no springs are fitted.
Posted: Sat May 23, 2009 1:45 pm
by Shadow
Corgie Carrier wrote:Shadow wrote:is rigid where the leaf spring is upside down (to normal) Bolted(clamped?) to the chassis in the middle, and each end of the spring attaches to an axle?
Rigid is where the trailer frame is welded to the axles, no springs are fitted.
fark that.
suspension is just tyres then?
Imagine if you git a pothole?
Posted: Sat May 23, 2009 1:51 pm
by ozy1
i have towed a rigid trailer loaded and unloaded, it towed nice when loaded, and towed like a bucket of shit when it was empty.
also think about the use of your car trailer, once you have it you will use it for picking up parts, picking up your broken down mates, so it will get alot of use empty,
i have had an issue when towing before comming to an extreemly steep hill, went to first and ran out of puff i stopped to go to low range, trailer dragged me backwards down the hill,over ride brakes dont do shot whan trailer and weight is dragging you backwardseven while i stood on the brakes took 5m for car brakes to pull it up,
go full eletric, they work either way, and would have solved this problem, combined with rocker springs it will tow well, stop well, if all built right.
Posted: Sat May 23, 2009 1:54 pm
by Shadow
ozy1 wrote:i have towed a rigid trailer loaded and unloaded, it towed nice when loaded, and towed like a bucket of shit when it was empty.
also think about the use of your car trailer, once you have it you will use it for picking up parts, picking up your broken down mates, so it will get alot of use empty,
i have had an issue when towing before comming to an extreemly steep hill, went to first and ran out of puff i stopped to go to low range, trailer dragged me backwards down the hill,over ride brakes dont do shot whan trailer and weight is dragging you backwardseven while i stood on the brakes took 5m for car brakes to pull it up,
go full eletric, they work either way, and would have solved this problem, combined with rocker springs it will tow well, stop well, if all built right.
the electric brakes my brother had on his tool trailer did not work in reverse.
They used an electomagnet which cl;amped to the inside face of the drum, which then used the friction between the magnet and rotating drum to drag a lever forward pushing the linings againt the drum.
in reverse they did not work at all.
Posted: Sat May 23, 2009 2:48 pm
by tweak'e
Shadow wrote:Corgie Carrier wrote:Shadow wrote:is rigid where the leaf spring is upside down (to normal) Bolted(clamped?) to the chassis in the middle, and each end of the spring attaches to an axle?
Rigid is where the trailer frame is welded to the axles, no springs are fitted.
fark that.
suspension is just tyres then?
Imagine if you git a pothole?
to right !
however i think the theory is that the suspension of the vechile tied to the trailer does all the work and dampens out the bumps.
however put a load of bricks on it and its a different story !
ozy1 wrote:i have had an issue when towing before comming to an extreemly steep hill, went to first and ran out of puff i stopped to go to low range, trailer dragged me backwards down the hill,over ride brakes dont do shot whan trailer and weight is dragging you backwardseven while i stood on the brakes took 5m for car brakes to pull it up,
does depend on how well the brakes come on. ours come on very quickly. you cannot reverse it without disabling the brakes. just rolling back into the trailer is enough to put the trailer brakes on.
however if a single set of brakes will hold all the weight on its own is another story
electrics can also have auto turn off in reverse, so you can back up with out having to turn the brakes off yourself.
as far as slipper vers roller (sorry not sure of exact terms) as an example have a look at the tandems at the bottom of this page
http://www.trojan.co.nz/index.asp?pageID=2145833592
a little bit of difference in heights. also have to watch the centre mount between the springs doesn't bottom out on the ground/etc.
Posted: Sat May 23, 2009 10:04 pm
by ozy1
Tweak'e
brakes in my trailer come on very quick as well, also i cant revers if i dont throw the latch over,
but coming to a stop and a steep hill and having the trailer drag you down, your hitch will not slide and enable the breaks if you get what im saying
Posted: Sat May 23, 2009 10:15 pm
by Shadow
ozy1 wrote:Tweak'e
brakes in my trailer come on very quick as well, also i cant revers if i dont throw the latch over,
but coming to a stop and a steep hill and having the trailer drag you down, your hitch will not slide and enable the breaks if you get what im saying
my brothers trailer wouldn't have braked either in that situation. Wheels need to be moving forwards to apply the brakes.
would have done the same thing.
Posted: Sat May 23, 2009 10:53 pm
by ozy1
Shadow wrote:ozy1 wrote:Tweak'e
brakes in my trailer come on very quick as well, also i cant revers if i dont throw the latch over,
but coming to a stop and a steep hill and having the trailer drag you down, your hitch will not slide and enable the breaks if you get what im saying
my brothers trailer wouldn't have braked either in that situation. Wheels need to be moving forwards to apply the brakes.
would have done the same thing.
wheels do move when your being dragged down the hill backwards, eletric brakes should work in this situation considering the magnet will be energised, but in reverse they normally only operate one shoe, where as in forwards direction it operates both shoes,
Posted: Sat May 23, 2009 10:56 pm
by narnturbogq
Rigids are dangerous pieces of s##t, and i would stay well clear of them. I've had two mates nearly write off their tow cars and the cars they were towing (one $65,000 total and the other $40,000 total)when using rigids, and they were only towing light cars (1000-1250 kgs), not comp trucks weighing between 2000-3000kgs.
I'm not sure about the road laws in your state but in Vic, when towing loads over 2000kgs (trailer and car(on the trailer) combined) the trailer must have brakes on all wheels and have a break-away system, so that if the trailer comes of the ball and takes off, the brakes lock on stopping the trailer from potentially killing someone.
Also be careful with the towing capacity of the tow vehicle, as most big car trailers weigh around 700 kgs, and add to that, most comp ready patrols would be getting up near 3000kgs, that doesnt leave much room to move on any tow vehicle, except for ford f250s or big Chevs.
Its all well and good until you hit someone, and then your in all sorts off sh#t, with the cops and insurance.
My advise is stay well clear of rigid trailers, and do some weight calculations of the comp truck and trailer combined, and make sure you can legally tow it , because the last thing you want to do is writeoff yours and someonelses car and and get fined by the cops and get shafted by your insurance company.
Good luck, Andrew
Posted: Sat May 23, 2009 11:00 pm
by Shadow
ozy1 wrote:Shadow wrote:ozy1 wrote:Tweak'e
brakes in my trailer come on very quick as well, also i cant revers if i dont throw the latch over,
but coming to a stop and a steep hill and having the trailer drag you down, your hitch will not slide and enable the breaks if you get what im saying
my brothers trailer wouldn't have braked either in that situation. Wheels need to be moving forwards to apply the brakes.
would have done the same thing.
wheels do move when your being dragged down the hill backwards, eletric brakes should work in this situation considering the magnet will be energised, but in reverse they normally only operate one shoe, where as in forwards direction it operates both shoes,
I will take your word for it, have only had a quick look at them when bro was changing the magnets.
If they did work in reverse, they work really crap compared to in forward.
In forward they would lock on a 2tonne loaded tool trailer. In reverse it didnt even seem like they were on (using the overide controller in car).
Posted: Sun May 24, 2009 11:13 am
by tweak'e
ozy1 wrote:Tweak'e
brakes in my trailer come on very quick as well, also i cant revers if i dont throw the latch over,
but coming to a stop and a steep hill and having the trailer drag you down, your hitch will not slide and enable the breaks if you get what im saying
i get what your saying easy enough, its just your trailer was going back faster than the tow vehicle

you probably stopped on the hill instead of rolling back into the trailer. ie let the trailer momentom push into you when you stopped and let the vechiles weight roll back into it keeping the brakes on.
certainly not a guaranteed thing to get right and that the situation is to be avoided in the first place.
also its much worse when the muppet driver hasn't got the hubs in !
the problem we have had is you don't have traction to go forward but the trailer brakes on forced on so you can't back and you can't get the brakes off.
Posted: Mon May 25, 2009 7:33 pm
by beebee
tweak'e wrote:ozy1 wrote:Tweak'e
brakes in my trailer come on very quick as well, also i cant revers if i dont throw the latch over,
but coming to a stop and a steep hill and having the trailer drag you down, your hitch will not slide and enable the breaks if you get what im saying
i get what your saying easy enough, its just your trailer was going back faster than the tow vehicle

you probably stopped on the hill instead of rolling back into the trailer. ie let the trailer momentom push into you when you stopped and let the vechiles weight roll back into it keeping the brakes on.
certainly not a guaranteed thing to get right and that the situation is to be avoided in the first place.
also its much worse when the muppet driver hasn't got the hubs in !
the problem we have had is you don't have traction to go forward but the trailer brakes on forced on so you can't back and you can't get the brakes off.
What the? As far as I can see, that makes no sense at all!
I witnessed an F250 get draged some 40-50m to the bottom of a hill when it ran out of traction and the trailer (with over-ride brakes) pulled it backwards. At the bottom it ran into another trailer parked off the side of the track that had done the same thing. Electric brakes with in cab control is the only SAFE way to go!
Posted: Mon May 25, 2009 7:49 pm
by Shadow
beebee wrote:tweak'e wrote:ozy1 wrote:Tweak'e
brakes in my trailer come on very quick as well, also i cant revers if i dont throw the latch over,
but coming to a stop and a steep hill and having the trailer drag you down, your hitch will not slide and enable the breaks if you get what im saying
i get what your saying easy enough, its just your trailer was going back faster than the tow vehicle

you probably stopped on the hill instead of rolling back into the trailer. ie let the trailer momentom push into you when you stopped and let the vechiles weight roll back into it keeping the brakes on.
certainly not a guaranteed thing to get right and that the situation is to be avoided in the first place.
also its much worse when the muppet driver hasn't got the hubs in !
the problem we have had is you don't have traction to go forward but the trailer brakes on forced on so you can't back and you can't get the brakes off.
What the? As far as I can see, that makes no sense at all!
I witnessed an F250 get draged some 40-50m to the bottom of a hill when it ran out of traction and the trailer (with over-ride brakes) pulled it backwards. At the bottom it ran into another trailer parked off the side of the track that had done the same thing. Electric brakes with in cab control is the only SAFE way to go!
He is suggesting that the momentum of the trailer will slam into the back of your car, activating the trailer brakes, then your car (cause you havent hit the brakes?) rolls backwards toward the trailer which keeps the brakes activated?
Not going to happen. when you losw traction your trailer has 0 momentum, and just skull drags you.
car trailer
Posted: Sun May 31, 2009 5:16 pm
by crumpy85
I build trailers every day off the week i would go for the rocker roller suspension3/5 tone rating whith 50mm Square Axle 12" Electric brakes on both axles whith a Breakaway and a in car brake controller its a bit over kill but better safe then sorry
Posted: Sun May 31, 2009 6:26 pm
by Athol
I'd suggest that you use an electric brake controller on the tow vehicle, but hydraulic on the trailer axles!
You can now get a combined master cylinder and hydraulic pump unit which takes an electric brake signal as its input and operates normal hydraulic drum wheel cylinders or disc calipers.
This means that you can use more reliable hydraulic brakes on the axles, but have electric brake control including breakaway.
I'm really not a fan of the electric drum brakes where the magnets drag around against the inside surface of the drum.
Posted: Sun May 31, 2009 6:42 pm
by ozy1
Athol wrote:
I'm really not a fan of the electric drum brakes where the magnets drag around against the inside surface of the drum.
what are you reasons behind this, am etreemly interested,
Posted: Sun May 31, 2009 7:00 pm
by Rhett
the only big adantage of that set up is(to my knowledge) boat trailers over 2 ton so you have to have in cab controled brakes and a break away unit, but don't have drum brakes that fill with salt water and rust.
Posted: Sun May 31, 2009 9:35 pm
by ozy1
Rhett wrote:the only big adantage of that set up is(to my knowledge) boat trailers over 2 ton so you have to have in cab controled brakes and a break away unit, but don't have drum brakes that fill with salt water and rust.
good point would love to hear if there is any other bonues
Posted: Sun May 31, 2009 9:45 pm
by Shadow
the magnets wear out and are expensive and wear the back of the drum aswell.
I bet electric over hydraulic would be more powerful aswell, but will definantly take more power. (good wiring on the tow vehicle).