Trailer question: Why don't trailers use shocks?

Trailer question: Why don't trailers use shocks? I've yet to see a car hauler with shocks.

Seems like a valid question, I understand that there is no one riding back there, but I'd like to think that having some kind of shock/ or dampener on a trailer (like a car hauler or trail trailer) would help stabilize the load.

For example: I'll bet it would help keep an unloaded trailer from bouncing.
Bouncing = tires not on the road.
Tires not on the road = not useful braking.

Obviously the valving would be different from a passenger vehicle, but has anyone else considered this idea?

It would be easy and inexpensive to get some short travel heavy valved shocks from the junkyard and try it out.

Plenty of trailers use shocks, but ride quality on a trailer isn't exactly a high priority.

This is a trailer being given away on another site. I have one that is very similar and I am going to put some shocks on it just like that one.

http://www.jeepforum.com/forum/f7/cross-promotion-pikes-peak-trailers-giveaway-1141363/

I'm not too worried about shocks but I do have the tires balanced. I have the worst luck with trailer tires as it is. Two summers ago I am headed to L. Powell and by the time I get to Paige I had replaced every tire but one including my spare that I had to put on 4 times. The tires were Good Year radial trailer tires that were only two years old. On the way back I lost one of my front tires on my Expedition. No one in rural Utah carries a 22" tire. The joke at my house is I need to get new rubber before any trips.

gravesdiggerxj said:

I understand that there is no one riding back there, but I'd like to think that having some kind of shock/ or dampener on a trailer (like a car hauler or trail trailer) would help stabilize the load.

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BCGPER said:

Plenty of trailers use shocks, but ride quality on a trailer isn't exactly a high priority.

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rholbrook said:

I'm not too worried about shocks but I do have the tires balanced...

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I get my trailer tires balanced too; I've had terrible luck with trailer tires. I don't even want to tell you how many tires I've lost in the last 2.5 years...

any other thoughts on the subject?

I get the load range E 2850lbs per tire and keep them at max air pressure 80 psi but my junk weighs 6000 lbs to. Alot less sidewall role.
Ive had pretty good luck with that.
Never tried shocks on a trailer before?

Found this in my Google search for greatness...

Hello, RME. Thanks for contacting Load Rite.
First, I am no engineer. But I will attempt a logical answer.
Load Rite has never equipped any of our trailers with shock absorbers, or
dampers. The job of a damper is just that, to dampen spring oscillation.
We have never had a complaint about our trailers being overly responsive to
road irregularities. However, when unladen a trailer will tend to bounce
more than when loaded to capacity.
Also, tires play an important role in dampening trailer axle movement.
Trailer tire sidewalls are constructed differently than passenger or light
truck tires. Perhaps some of the more bouncy trailers you've witnessed were
equipped with the incorrect tires.
Another factor is tongue weight. Improperly set tongue weight will amplify
trailer suspension movements into the tow vehicle frame and will result in
an ill handling rig.
I hope that some of this information is useful to you.
Sincerely,

Mike Sodano
Customer Service Manager
Load Rite Trailers, Inc.

Makes sense to me.

bryson said:

Found this in my Google search for greatness...

Hello, RME. Thanks for contacting Load Rite.
First, I am no engineer. But I will attempt a logical answer.
Load Rite has never equipped any of our trailers with shock absorbers, or
dampers. The job of a damper is just that, to dampen spring oscillation.
We have never had a complaint about our trailers being overly responsive to
road irregularities. However, when unladen a trailer will tend to bounce
more than when loaded to capacity.
Also, tires play an important role in dampening trailer axle movement.
Trailer tire sidewalls are constructed differently than passenger or light
truck tires. Perhaps some of the more bouncy trailers you've witnessed were
equipped with the incorrect tires.
Another factor is tongue weight. Improperly set tongue weight will amplify
trailer suspension movements into the tow vehicle frame and will result in
an ill handling rig.
I hope that some of this information is useful to you.
Sincerely,

Mike Sodano
Customer Service Manager
Load Rite Trailers, Inc.

Makes sense to me.

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Interesting info there. I've had unbelievably horrific luck with trailer tires no matter what brand of tire or trailer that I have (travel trailer or flatbed). I've had E-rated truck tires on my flatbed for the past year and have been pretty happy with them. I wonder if I added a shock, if that would make it "cool" from an engineering perspective?

If you're blowing out trailer tires, go buy a set of Maxxis M8008 trailer tires!

I put g rated on my goose neck. I finally stopped loosing a tire or two each trip. I've only lost one since and it was because I hit something on the road.

Cherokeester said:

This is a trailer being given away on another site. I have one that is very similar and I am going to put some shocks on it just like that one.

http://www.jeepforum.com/forum/f7/cross-promotion-pikes-peak-trailers-giveaway-1141363/

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Pretty sure the way those shocks are mounted isn't going to do a thing but wear out the bushings. Unless I am looking at it wrong.

lewis said:

Pretty sure the way those shocks are mounted isn't going to do a thing but wear out the bushings. Unless I am looking at it wrong.

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Yeah those aren't going to do anything! Lol

cjncustoms said:

Yeah those aren't going to do anything! Lol

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Seriously, WTF?

Yeah you are right, I didn't look at the picture close enough. I just like the idea though.

I think those shocks are just for looks.

Unless it's some cool airbag system (or something like that) I don't think any trailer suspension moves enough for a shock to do anything anyway. All shock absorption is done by the tires.

One way to look at it, is that when you consider the role of the shock, it is to damp oscillations of the suspension. The oscillations occur when the spring cycles more than one time, i.e. bounces. Now, consider that on most trailers, a high spring rate is employed to carry heavy loads; then, when a trailer is loaded, the load doesn't move, only the wheel moves (ideally). The mass of the load actually dampens the movement of the wheel. This is obvious if you consider the following: remove the rear leaf springs for a 1 ton truck, and put them on a stock samurai. The springs will not really move very much, and its almost like there is no suspension. This is the unloaded trailer. Then, put the samurai springs on the truck; here the springs will compress and the truck will not really move at all (provided the truck hasn't maxed the suspension to the bump stops). This is the loaded trailer.

Now, the reason the shock would be useless in most situations, is that on the unloaded trailer, the suspension doesn't move, therefore there is no movement to damp, and the shock just sits there (i.e. no cycling of the suspension).

On the loaded trailer, the load acts as the damping force for the system, and a shock would be redundant.

Keep in mind also, that ride quality is not a factor. In that respect, a trailer suspensions only two duties are to carry a load without compressing completely, and to allow the driver to maintain control of the trailer. Cost is also a factor. Finally, realize that a suspension where shocks play pivotal role (i.e. a vehicle) is not able to carry much weight. Compare a truck, even a 1 ton, to a trailer that easily haul 5000lbs. Then think how much more it would cost to make that trailer suspension feel and perform like the trucks in terms of ride quality.

So why does the military run shocks then?

Cost is usually not a factor with the military, and not all military trailers have shocks; in any case, where shocks would be useful is in off road applications, which is where the military often uses their equipment, i.e. dirt roads and such. Also, the bigger the trailer, the more effective shocks would be. Any smaller trailer would not need them as much, or, the cost would usually negate the benefits.

Shocks are like $20 each. Even a small gain would be worth it.

Chevycrew said:

Shocks are like $20 each. Even a small gain would be worth it.

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Not to the military

2 shocks with mounts and fabrication could easily add $100+ to the cost of a new trailer. Most likely more as a 'decent' shock is not $20 more like $50-60 each. So when 95% are fine without shocks, are they going to pay the $200 premium for the shocks? There are plenty of things that would offer 'small gains' on a trailer, needed or not. How about brakes on a light trailer, how about additional lights, 12V battery backup systems, stand-alone park brakes (again think military). At the end of the day the trailer manufactures have a product to market and sale and hopefully at a lower price than their competitors with some level of margin for themselves.

I think often more important than cost is practicality. We've already discussed the practicality of price relating to function but in many, many trailer applications the size constraints alone don't offer much in the way of room for shocks. For example the average car hauler or light utility trailer would not lend itself well to a traditional vertical shock mount setup. Military trailers have a plethora of room, my Big Bubba car hauler does not.