Solid axle versus independent suspension

[HuddExpo]

trailers don't follow exactly where your rig does, your rigs axle is much stronger, and can handle scraping on things a lot better. your rig will articulate a lot more than your trailer will. If you're doing hardcore wheeling with a trailer, it's a no brainer independent will be better for it. Handles bumps FAR better as well. where a solid axle rig will articulate to keep tires on the ground over uneven terrain, a solid axle trailer will not. independent will allow it to stay more even, and less chance of tipping, less strain on the hitching mechanism, the list goes on and on. also not everyone runs the same size tire on their trailer. I wont be. I will only have 31.7" tires on my trailer. so my clearance will be a lot less on the trailer.


that being said, I'm putting a solid axle under mine. as the pros of independent don't outweigh the pros of a solid axle for my application. They each have their place. It's about finding what works for you.

How it rides has more to do with spring rate than the type of suspension. The spring rate also helps dictate when and if a wheel will leave the ground and how much the trailer will tilt when traversing rough terrain. I have had all types and my trailer with the long, wide soft leaf springs rides better than all the rest by a long shot. I would also say it has the lowest spring rate of all of them. Trailers don't articulate, its virtually impossible without the opposing forces you get with a four wheeled vehicle, so articulation on a trailer is basically fiction. I have yet to see an indepent suspension or torsion axle on a trailer ride anywhere near as nice as my teardrop. I am not saying independent isn't a good and a well engineered design, I just can't get into that camp from the 10's of thousands of miles I have driven with all types. The long soft leaf design is the way to go IMO. That 3500lb axle tube can take a pretty good beating as well.

 

[Rath]

here is actually a good video. in a lot of cases, the independent is far better. this video does use a swingarm type independent, but even still, it works better for these types of situations.
And even the swingarm style isn't as bad for ground clearance, and each side can rub upon and be dragged over obstacles where a solid axle would simply get stuck on and hung up. of course, wouldnt work for reversing, but if you need to reverse with a trailer over rough terrain you're not going to have a good time regardless of suspension type.

 

[HuddExpo]

I have seen them in person. And I have seen them on the trails too. you do realize there are different types of independent suspensions, right? Because what you're describing isn't the best if you want ground clearance alone. However, that system is still a better offroad option than a solid axle for a trailer.

Although I can understand why a lot of people would argue about its benefits. It's rare for someone to actually take a trailer through conditions that would most benefit from IS.

Most people mentioning torsional independant suspension also are not talking about what you are talking about. Most common would be a Timbren axleless suspension. seen here.

VERY low profile, takes up very little space. fantastic for rough offroad trails. if you see it vs solid axle on a rough trail you'll understand its benefits. But again, for most people, yeah, a solid axle will be suitable.

Is there any dampening in this design? I have been out with trailers like this, but never saw them drive it over rough, choppy stuff. I would think it may end up bouncy on that stuff.

 

[Rath]

I am not saying independent isn't a good and a well engineered design, I just can't get into that camp from the 10's of thousands of miles I have driven with all types. The long soft leaf design is the way to go IMO.

I can 100% agree with you on this.

 

[Rath]

Is there any dampening in this design? I have been out with trailers like this, but never saw them drive it over rough, choppy stuff. I would think it may end up bouncy on that stuff.

It depends on the style/brand you get.

 

[HuddExpo]

here is actually a good video. in a lot of cases, the independent is far better. this video does use a swingarm type independent, but even still, it works better for these types of situations.
And even the swingarm style isn't as bad for ground clearance, and each side can rub upon and be dragged over obstacles where a solid axle would simply get stuck on and hung up. of course, wouldnt work for reversing, but if you need to reverse with a trailer over rough terrain you're not going to have a good time regardless of suspension type.

I have seen this, thanks. I especially like the 7:00-9:30min section. That is probably the best example of the two types working through the same terrain. I could still argue about which is better, but it is just my opinion. I will however stick to arguing that spring rate is the biggest factor in ride quality. To bad the leaf spring trailer in this video didn't have shocks like the swing arm trailer did.

 

[Rath]

agreed on spring rate making a big difference.

I dunno, Im not arguing ones better than the other here. I personally have only, and likely will only, use a solid axle type because its simple. But I cannot deny the benefits of the independent.

One thing I actually will be doing on mine, getting inspiration from the independent, is making a "skid plate" for the axle. so if I do come across anything that would otherwise cause my trailer to get hung up, my axle can slide over it much like an independent swingarm would.

 

[m_lars]

I have seen them in person. And I have seen them on the trails too. you do realize there are different types of independent suspensions, right? Because what you're describing isn't the best if you want ground clearance alone. However, that system is still a better offroad option than a solid axle for a trailer.

Although I can understand why a lot of people would argue about its benefits. It's rare for someone to actually take a trailer through conditions that would most benefit from IS.

Most people mentioning torsional independant suspension also are not talking about what you are talking about. Most common would be a Timbren axleless suspension. seen here.

VERY low profile, takes up very little space. fantastic for rough offroad trails. if you see it vs solid axle on a rough trail you'll understand its benefits. But again, for most people, yeah, a solid axle will be suitable.

I understand that there are different types. In the post you quoted of mine I was speaking of the trailers I further explained. I was assuming we were speaking of the same thing.

 

[MOAK]

Good for your decision.
One side or the other of a single axle or axeless trailer suspension is not going to compress or droop in uneven terrain. The entire trailer will articulate at the hitch point.

 

[MOAK]

agreed on spring rate making a big difference.

I dunno, Im not arguing ones better than the other here. I personally have only, and likely will only, use a solid axle type because its simple. But I cannot deny the benefits of the independent.

One thing I actually will be doing on mine, getting inspiration from the independent, is making a "skid plate" for the axle. so if I do come across anything that would otherwise cause my trailer to get hung up, my axle can slide over it much like an independent swingarm would.

Years ago I had a skid plate fabbed up for mine. After testing the trailer on multiple “ black” trails at Rausch Creek there wasn’t a single scratch on it. The axle on my trailer provides about 4” more clearance than on my vehicle and contrary to what many believe, does track perfectly. That’s why the same track width is so important. A trailer company in Colorado went out of business a while back. They were selling the idea that a narrower tracked trailer was easier to maneuver. It just isn’t so.

 

[Rath]

Years ago I had a skid plate fabbed up for mine. After testing the trailer on multiple “ black” trails at Rausch Creek there wasn’t a single scratch on it. The axle on my trailer provides about 4” more clearance than on my vehicle and contrary to what many believe, does track perfectly. That’s why the same track width is so important. A trailer company in Colorado went out of business a while back. They were selling the idea that a narrower tracked trailer was easier to maneuver. It just isn’t so.

Of course if you keep track width the exact same, and length is right, it will track very close. But that's not always the case.

I won't have as much clearance in my trailer axles as my truck will have, but I also won't be taking the trailer on the more extreme trails. My trailer will be a basecamp setup that gets left behind on day adventures.

 

[smritte]

I'm going to agree and disagree with the video. The disagree part is, that wasn't a suspension test. It was 2 unequal suspensions being compared. I don't mean independent vs solid, im talking about one shocked not the other and what about spring rate and vehicle weight. They also needed same tire height as the tow vehicles.
What the video did show was why you need shocks and why I design my trailers to follow my track.
I too have compared over the years and what I see is more people set up the suspension as a "trailer" and drive it in terrain that requires a different suspension tune.

Years ago I had a skid plate fabbed up for mine. After testing the trailer on multiple “ black” trails at Rausch Creek there wasn’t a single scratch on it. The axle on my trailer provides about 4” more clearance than on my vehicle and contrary to what many believe, does track perfectly. That’s why the same track width is so important. A trailer company in Colorado went out of business a while back. They were selling the idea that a narrower tracked trailer was easier to maneuver. It just isn’t so.

This ^^^^^^^^^^
My M100 has been over Dusy/Irshem, Rubicon, Fordice as well as 60+ mph across a dry lake.
Bottom line is, its a trailer. Either works well if set up properly. Where one has an advantage, the other has an advantage in a different area. For me, independent are more money, more maintenance and no real benefit.

 

[Road]

I can tell you from a few years and a ton of miles experience with a Dexter 2300# torsion axle on my trailer, and decades of experience before that with straight axles with leaf springs, I much prefer this torsion axle for both back country and highway travel.

It's not axle-less, as there is a bar that goes from one side to the other attached to the wheel setups and containing the torsion rubbers, though the bar is higher than a conventional straight axle would be for the same height deck. It does not go from the center of the wheel. That allows a higher center clearance under my trailer, which in my experience is what is needed more on trails than side clearance heights at/near the wheels.

Time after time, especially back country, I've watched as one wheel dips into a pocket or rises over a bump while the trailer stays relatively level, where a straight axle would tilt the trailer more, and by exagerration the rack and RTT even more. Continued lowering on one side or the other, like a long groove on one side of a track will result in the trailer leaning, sure, but with the momentary dip or rise from large rocks, roots, etc, the trailer stays far more level. Therefore far less jarring to its contents.

My trailer curb weight is 1125#, payload is 2375# for a GW max of 3500#.
I'm usually closer to the max, from the one time I put it on pro scales.


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[Jeep backroads]

Good information on this thread. My trailer has a straight axle and I’m planning on upgrading because I’m going up to 35 inch tires so they match the vehicle. But I’m not sure what kind of axle to buy stick with solid or try something else.

 

[smritte]

You can buy a Dexter solid axle with brakes for 350-400. If you can weld, I run CJ7 rear springs with 2.5 lift. I also add in a gas shock. My M-100 with the configuration has been all over. Simple, good part availability and rugged.
There's a little more info in my tear drop build thread, in my sig.

 

[TX_Big_Rig]

The Dexter Torsion axles can be ordered so they have a 45 degree downturn. That puts the axle several inches above the centerline of the wheel. I almost hit the order button on that. I'd recommend it for any small trailer, over any other suspension type. They are smooth as butter and perform better as some of you described above. I've had it on my Popup for 30yrs.

However, my popup is much larger and wider than a standard overland trailer, so I opted for the Cruisemaster system. Yes, the shocks are about 3-4" below centerline, but that is next to the wheel. They perform better than a solid or tosion axle and are built much better. I didn't want to risk hanging up that 1" square tube axle and have my diesel truck just keep on pulling. Probably wouldn't feel it. lol The Cruisemaster's in theory would get dragged over it and hold up better to any abuse. They are also very serviceable and can be suited to your particular weight.

There are several videos out there comparing the same trailer on leafs, torsions, Timbrens, and swingarm/independent. The camera is right there under the frame. You can make that judgement just watching the videos for yourself. Plus the Aussies have gone independent 15yrs ago and don't they hold the bar for this stuff?

 

[m_lars]

Plus the Aussies have gone independent 15yrs ago and don't they hold the bar for this stuff?

They also charge double what I paid for my first house for a trailer with a tent on top!

 

[smritte]

There are several videos out there comparing the same trailer on leafs, torsions, Timbrens, and swingarm/independent. The camera is right there under the frame. You can make that judgement just watching the videos for yourself. Plus the Aussies have gone independent 15yrs ago and don't they hold the bar for this stuff?

I have yet to see a video that compared properly. All of the videos I've seen were not done comparing the same weight vehicle with the same shocks, same spring weight and same wheel base. If these videos exist I haven't found them.

All systems have pros and cons. Where one shines, it fail's somewhere else. Most of the videos I've watched were biased toward what they wanted the outcome to be, which was based on the fact the ones doing the videos didn't actually understand how suspensions work or they wanted you to buy a certain one.
In the video attached to this thread, They refer to the leaf spring by how many springs are in the pack which doesn't tell you anything. The video from underneath showed one vehicle had shocks and the other didn't. One of the drivers seemed to know his rig and the other didn't. In my opinion, that was a poor comparison.

 

[TX_Big_Rig]

They also charge double what I paid for my first house for a trailer with a tent on top!

I'm paying freight and import costs that equal exactly what I paid for the suspension kit itself. I'm betting even with loading up full containers, they are facing the same costs to get those trailers here. Then there's resale taxes, dealer fees, etc. Did you try comparing the same trailer in AU dollars over there?

 

[Jeep backroads]

You can buy a Dexter solid axle with brakes for 350-400. If you can weld, I run CJ7 rear springs with 2.5 lift. I also add in a gas shock. My M-100 with the configuration has been all over. Simple, good part availability and rugged.
There's a little more info in my tear drop build thread, in my sig.

I really don’t need brakes but will look at the axle.