Why did you choose this over leaf springs? What is the advantage. Thanks.
Trailer suspension options?
- Thread starter Brettski
- Start date
Why did you choose this over leaf springs? What is the advantage. Thanks.
taken from Adventure Trailers website.
MAXIMUM LOAD vs. SMOOTH RIDE: The challenge is that the leaf springs must be rated for the maximum load that the trailer might carry. We wanted a smooth ride no matter if the trailer was full or empty. We also wanted to maintain travel regardless of load. A trailer with leaf spring compresses the springs under load effectively reducing the travel, or reducing the amount the springs could compress to absorb shock. Our ideal system would have to have some method of maintaining travel no matter what the load.
LOAD: A typical SUV 's (Jeep Grande Cherokee) curb weight is 3669 lbs, the gross Vehicle Weight Rating (GVWR) is 5700 lbs. a payload of 2031 lbs. The payload is 55% over the curb weight.
When we look at our trailers we realized that the curb weight was 700 lbs, and the GVWR was 2700 lbs. a payload of 2000 lbs. The payload was 285% over the curb weight !!! Extrapolating that out, to get some idea of the GVWR of an SUV if it's payload was 285% of the curb weight, we found that the vehicle would have weighed 10,457 lbs.
The advantage is the ability to tune the airspring to match the load.
MAXIMUM LOAD vs. SMOOTH RIDE: The challenge is that the leaf springs must be rated for the maximum load that the trailer might carry. We wanted a smooth ride no matter if the trailer was full or empty. We also wanted to maintain travel regardless of load. A trailer with leaf spring compresses the springs under load effectively reducing the travel, or reducing the amount the springs could compress to absorb shock. Our ideal system would have to have some method of maintaining travel no matter what the load.
LOAD: A typical SUV 's (Jeep Grande Cherokee) curb weight is 3669 lbs, the gross Vehicle Weight Rating (GVWR) is 5700 lbs. a payload of 2031 lbs. The payload is 55% over the curb weight.
When we look at our trailers we realized that the curb weight was 700 lbs, and the GVWR was 2700 lbs. a payload of 2000 lbs. The payload was 285% over the curb weight !!! Extrapolating that out, to get some idea of the GVWR of an SUV if it's payload was 285% of the curb weight, we found that the vehicle would have weighed 10,457 lbs.
The advantage is the ability to tune the airspring to match the load.
old_man
Adventurer
I'm an avid 4x4 fabricator. I also have worked on several rides that I bagged with my son in law. Air bags give you great flexibility. They yield a smooth ride and can be adjusted to meet your load and set your ride height. Bottom line is that they are inexpensive and easy to implement. With the shocks, I could not ask for a better pulling and riding trailer. The shocks damp any excessive rebound and the trailer can take bumps with a minimal impact on the contents. If I get in a spot where a greater departure angle is needed, even though I can drag the back of the trailer without damage, all I need to do is air up and presto, I have 4-6 inches greater clearance. This is also nice for water crossings. I have actually done severe side hill trails where I aired down the uphill bag and filled the down hill bag to move the CG. Try that with springs.
Also, if you end up with more weight on one side than the other, it is easy to level out the trailer.
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Box Rocket
Well-known member
Most cost effective and reliable is going to be leaf springs. Very little to go wrong with leaf springs. Airbags and fancy trailing arms have some benefits, but a properly built leaf sprung trailer can ride very well. More importantly, the chances of a leaf spring failure are very low. Chance of an airbag or timbren suspension failure is quite a bit higher because they are just more susceptible to damage and wear. I know the fans of airbags etc are going to argue most of my points, but pure cost and reliability, there's no contest. I paid a whopping $15 for the suspension on my trailer.
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You won't win "cool factor" points with a leaf sprung trailer, but you'll make it to the next camp when someone else has an airbag failure (hope they carry spares), or have a trailing arm break or or brackets tear off the frame. (I've seen both happen) and the trailers were stranded where they were until repairs could be made. In the rare instance where you have a breakdown related to leaf springs, I've had one....I had a spring hanger separate from the frame, without much trouble you can continue travel. I threw a ratchet strap around the axle to keep it in the wheel well and drove another 200+ miles of trail until I got to a shop where I could reweld the spring hanger. No way I could have done that with an airbag or trailing arm failure unless I had spares.
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To be clear, I don't have anything against, airbags, trailing arms, or other suspension options. They're cool and they can work really well. I'll admit that ride and height adjustability of air bags is a neat feature and I can see it's usefulness in certain situations. For me, I just wanted something I didn't need to worry about in remote areas. For that reason, I'm a fan of leaf springs and use that on my trailer. Is it the best solution for every trailer, probably not, but for small offroad type trailers, it's a great option.
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I've shared this before but maybe it's useful here. This is a video of my trailer from a couple years ago, through some fairly rough terrain, and I don't have a problem pulling it pretty fast. Not rockcrawling by any means but definitely worse than a graded fire road. This is with cheap trailer leaf springs, no shocks, and about 15psi in the tires. (If you are using LT tires like many of us, too many people have too much air in them IMO. They are designed to be under a much heavier truck so they easily handle lower pressure under a much lighter trailer. This helps ride quality in a big way.)
https://youtu.be/N7F5GCh2dwg
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Here's my trailer as of today, built it 8 years ago. Still leaf sprung with lots and lots of miles.
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Just my opinion, and I'm no expert. But suspension travel on a trailer is often over emphasized and misunderstood by new builders/buyers. A trailer just doesn't need to have the same kind of travel that the tow rig has. And to get anything close to that would require springs so soft that the load capacity would not be good. I believe that suspension compliance (think, don't break the eggs in my food bin) should be the priority, not the amount of travel in the suspension. This can be achieved with very minimal travel.
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You won't win "cool factor" points with a leaf sprung trailer, but you'll make it to the next camp when someone else has an airbag failure (hope they carry spares), or have a trailing arm break or or brackets tear off the frame. (I've seen both happen) and the trailers were stranded where they were until repairs could be made. In the rare instance where you have a breakdown related to leaf springs, I've had one....I had a spring hanger separate from the frame, without much trouble you can continue travel. I threw a ratchet strap around the axle to keep it in the wheel well and drove another 200+ miles of trail until I got to a shop where I could reweld the spring hanger. No way I could have done that with an airbag or trailing arm failure unless I had spares.
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To be clear, I don't have anything against, airbags, trailing arms, or other suspension options. They're cool and they can work really well. I'll admit that ride and height adjustability of air bags is a neat feature and I can see it's usefulness in certain situations. For me, I just wanted something I didn't need to worry about in remote areas. For that reason, I'm a fan of leaf springs and use that on my trailer. Is it the best solution for every trailer, probably not, but for small offroad type trailers, it's a great option.
.
I've shared this before but maybe it's useful here. This is a video of my trailer from a couple years ago, through some fairly rough terrain, and I don't have a problem pulling it pretty fast. Not rockcrawling by any means but definitely worse than a graded fire road. This is with cheap trailer leaf springs, no shocks, and about 15psi in the tires. (If you are using LT tires like many of us, too many people have too much air in them IMO. They are designed to be under a much heavier truck so they easily handle lower pressure under a much lighter trailer. This helps ride quality in a big way.)
https://youtu.be/N7F5GCh2dwg
.
Here's my trailer as of today, built it 8 years ago. Still leaf sprung with lots and lots of miles.
.
Just my opinion, and I'm no expert. But suspension travel on a trailer is often over emphasized and misunderstood by new builders/buyers. A trailer just doesn't need to have the same kind of travel that the tow rig has. And to get anything close to that would require springs so soft that the load capacity would not be good. I believe that suspension compliance (think, don't break the eggs in my food bin) should be the priority, not the amount of travel in the suspension. This can be achieved with very minimal travel.
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Hello all-
Making a lot of progress now that we've actually started our build. I'll start a new thread shortly, but for now a question:
I have 2500# springs on here (1250 per side). I doubt this thing will ever weigh over 2000. Does anyone know how much compression space the springs might need? We're thinking of putting the axle over the spring in order to lower the frame, so we can build the cabin a little taller (and still fit in a standard garage). Thoughts?
Making a lot of progress now that we've actually started our build. I'll start a new thread shortly, but for now a question:
I have 2500# springs on here (1250 per side). I doubt this thing will ever weigh over 2000. Does anyone know how much compression space the springs might need? We're thinking of putting the axle over the spring in order to lower the frame, so we can build the cabin a little taller (and still fit in a standard garage). Thoughts?
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workingonit71
Aspirantes ad Adventure
off-road with leaf suspension; spring over axle, short cabin height for stability
- You've already answered your own questions; don't waver now. The way you have your springs over your axle is the way to go, for maximum ground clearance, so don't compromise that, to gain cabin height. Not only will you lose trail ability, by lowering the frame, a tall cabin will be more unstable on uneven ground, and have added wind resistance when being towed.
- Most small trailers, unless you need the comforts of home inside, are usually 4' from the frame up, or less. Part of the reason for that, is the traditional, most common size of the wall-building material (usually plywood, but increasingly of some composite), which is the 4'x8' sheet. I built my squareback trailer entirely based on 4'x8' sheets of 3/4" plywood. My interior is only 48" tall, inside, but until I began having knee and back problems (I'm 66), it was sufficient to sit up in, or change clothes inside.
- My trailer has the springs under the axle (since I don't anticipate rock-climbing with it), and is 24" at the top of the frame, so overall height is 24"+48"+.75"+.75"=73.5". It easily clears the garage door, though there is an abrupt ramp making the trailer jump up 3-4". Most garage entrances have a minimum of 6'6" (78"), so that should be easily met by the usual trailer, with a 4 foot inside height. If you need to change the way you already have your frame set, be sure to consider the repercussions, on and off-road, first.
I am getting ready to start building an offroad trailer. I will be using a new 3500# straight tube axle, and 2x3x3/16" frame tube.
So right now, I am trying to figure the Leaf springs out for it. Debating on finding automotive leaf packs at the salvage yard, or just using a new set of trailer leaf packs from Redneck. Salvage yard springs are $50/set, and the new Redneck packs are much higher.
What style are others using for builds?
I have been looking, but haven't really come across information saying the types of leaf springs commonly being used. My Google Foo, isn't strong with this one I guess. lol I was hoping this thread had more specific info, but maybe this question will keep it going. Unless there is other threads on this topic?
So right now, I am trying to figure the Leaf springs out for it. Debating on finding automotive leaf packs at the salvage yard, or just using a new set of trailer leaf packs from Redneck. Salvage yard springs are $50/set, and the new Redneck packs are much higher.
What style are others using for builds?
I have been looking, but haven't really come across information saying the types of leaf springs commonly being used. My Google Foo, isn't strong with this one I guess. lol I was hoping this thread had more specific info, but maybe this question will keep it going. Unless there is other threads on this topic?
bluejeep
just a guy
experienced vote for bags
coming in late to the game - oh well, my apologies. I built a trailer that I used to tow my jeep to events. It was heavy duty, being that the load was 4500 - 5000 lbs.
Used firestone airbags, and designed it so the back of the trailer sat on the ground when I lowered the pressure in the bags. Just drove on or off, aired up and headed down the road. Sold the trailer years ago. Only change I would have ever made if I still had it would have been to go with double axle.
Smoothest riding trailer I have ever experienced, by a long shot. That's whether it was fully loaded or completely empty. Just adjust the pressure. Neither my dodge ram nor the dakota was aware they were towing anything
If I ever were to build another trailer of any size I wouldn't even hesitate - bag it straight away.
Been toying with going bag over coils on the Jeep for the same reasons :Wow1:
coming in late to the game - oh well, my apologies. I built a trailer that I used to tow my jeep to events. It was heavy duty, being that the load was 4500 - 5000 lbs.
Used firestone airbags, and designed it so the back of the trailer sat on the ground when I lowered the pressure in the bags. Just drove on or off, aired up and headed down the road. Sold the trailer years ago. Only change I would have ever made if I still had it would have been to go with double axle.
Smoothest riding trailer I have ever experienced, by a long shot. That's whether it was fully loaded or completely empty. Just adjust the pressure. Neither my dodge ram nor the dakota was aware they were towing anything
If I ever were to build another trailer of any size I wouldn't even hesitate - bag it straight away.
Been toying with going bag over coils on the Jeep for the same reasons :Wow1:
rnArmy
Adventurer
Most folks will use an eye-to-eye leaf spring for their trailers. Some trailers will come from the factory with slipper springs - to be blunt they suck - don't go there. Eye-to-eye springs have a shackle at the back end just like on a Jeep (or the old military trailers).
Folks tend to go too heavy with their springs figuring "more is better". Not true. You need to select your spring rate based on your UNSPRUNG weight (which is everything ABOVE the spring mounts). Here's where I got my trailer springs:
http://www.stengelbros.net/Eye-Eye-Trailer-Springs_c_254.html Pick a weight limit and length (longer is better). Weight rating is per individual spring, so double it for the pair.
I'm running these on my little trailer: http://www.stengelbros.net/US-1001-...l-Length-575-lb-rating-per-spring_p_1688.html
If you get springs that are 1.75" wide (the most common width), that's the same width of the early military trailer and Jeep's (think flat fender Jeeps), so you can use the same mounting hardware. I actually modified the holes on some early Jeep axle-to-spring mounting plates so I could use them as the shock lower mounts.
I too am running a 3500lb axle under the springs with electric brakes (third picture shows a previous axle mounted above the springs).
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Already have a new straight axle, and plan on going sprung over with it.
Already committed to using a hanger & shackle on an eye to eye leaf pack.
Older Toyota Taco leafs are 2" wide, but are way longer than trailer springs. Choosing one of these was my hangup.
Seems like going with the trailer made packs, I can get all the hardware/hangers/shackles easily, and at the ready anywhere in case of a breakdown.
For the ease of install, and repairs, I will go with the trailer packs. Thanks for the help guys.
Already committed to using a hanger & shackle on an eye to eye leaf pack.
Older Toyota Taco leafs are 2" wide, but are way longer than trailer springs. Choosing one of these was my hangup.
Seems like going with the trailer made packs, I can get all the hardware/hangers/shackles easily, and at the ready anywhere in case of a breakdown.
For the ease of install, and repairs, I will go with the trailer packs. Thanks for the help guys.
deepmud
Adventurer
I can see that with specific rocks it could be a bummer - but you should be able to drive accordingly and put your tire on it - or it would end up right down the middle and not hit the usual straight axle either......
But a wedge of steel as a slider might not be a bad idea of you are a serious rock-crawler.
But a wedge of steel as a slider might not be a bad idea of you are a serious rock-crawler.
Why wouldn't anyone use a low weight lead spring and run a bag on tomofnit.
That way when your emptynor light, ounare just running the spring, and when you get heavy you air up the bag.
My f350 rear suspension had a Kedelman (sp?) Air suspension set up like this. So when I had nothing in the truck I was all aired down and sprung only on leafs, and when I hooked a trailer or loaded the bed if needed be, I would fill the bags...
That way when your emptynor light, ounare just running the spring, and when you get heavy you air up the bag.
My f350 rear suspension had a Kedelman (sp?) Air suspension set up like this. So when I had nothing in the truck I was all aired down and sprung only on leafs, and when I hooked a trailer or loaded the bed if needed be, I would fill the bags...
I wanted to run these, but E-Trailer.com rep said they don't make a 5 bolt brake hub in a 5 on 4-1/2" lug pattern, that will work on the 3500#, only for the 2000# setup.
