I would suspect it is kind of like cars...if you want the bigger engine, you usually have to get a lot of unneeded bells and whistles with it. If you want shocks on you car hauler, you have to go ahead and pay the premium to get them, and in the process pay for a bunch of stuff you don't need. But, I would imagine that a lot of military trailers that see off road use have a shock system in place (at least the bigger ones). But, from experience I know most that see pavement use do not.
Trailer question: Why don't trailers use shocks?
- Thread starter Gravy
- Start date
RockMonkey
Suddenly Enthusiastic
If we're talking about a car-hauler trailer, if you strap the axles to the trailer deck and not the body, the shocks on the vehicle will act as shocks for the trailer.
- Location
- Riverton, UT
The old military trailer I sold to RustEoltrux's friend in Idaho had no springs and it only had a problem when unloaded. It bounced all over the place.
- Location
- The Land Northward (Bountiful), Utah
Not to the military
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.
I haven't seen under your particular trailer, but under mine I have plenty of room to run a vertical shock, it may only be 6" of travel, but that should be enough.
Let's talk about valving:
We are looking at tons on sprung weight: (up to 6k lbs)
Very little unsprung weight: (I'm guessing 300-400lbs)
Junkyard shocks are $5.99 and I can fabricate mounts with scrap.
What will be the closest match on travel and valving?
My guess would be front shocks off an IFS 3/4ton truck.
Maybe I'll look through Rancho's catalog and look at valving for stock truck applications.
Let us know how it goes! My guess is you'll see approximately zero difference, but it might give you a warm fuzzy feeling to know there are shocks there.
- Location
- The Land Northward (Bountiful), Utah
Let us know how it goes! My guess is you'll see approximately zero difference, but it might give you a warm fuzzy feeling to know there are shocks there.
burn ha
If they don't make a difference I'll be out $25 and some free time, no stress.
If I have some free time I may get to this
Shocks on Trailers
Hi everyone -
My name is Dave Williams. I am the owner, designer, and builder PikesPeakTrailers.com. I saw references to our site from this website when looking at our web logs and decided to check it out.
The trailer being referenced is one that we built and was used as a giveaway. I am writing to address the use of shocks on trailers. My comments are specifically directed about the trailers we build which are designed to be taken off the highway. Our design characteristics and components we use have been tested over 10s of thousands of hwy miles and hundreds of trail miles. This include a variety of off conditions: rockcrawling, beach, fireroad, etc.
So, with this as a background, here is what I can tell you - for certain conditions the correct dampening system (shock) can make a tremendous difference in how a trailer behaves. Below are tested and observed facts, again specifically to our trailers.
-If the trailer is oversprung and does not flex, as many trailers are, shocks will not matter.
-Even when properly sprung to flex some when empty and more when loaded, hwy based travel does not benefit much from shocks as the bumps in the road are insignificant enough to cause much tracking disturbance or hop.
-By far, the biggest benefit we have seen to adding shocks is off road. The trailers are light enough so that, when used without shocks, hitting a large obstacle with a tire on one side can cause a severe pogo effect as the kinetic energy in the compressed spring fires back violently. This can cause the trailer, especially one side, to rebound and for the tire to get air. Proper dampening dramatically mitigates this.
-On washboard or other small tight terrain the effect is similar those understated. We have many hrs of video footage from a following vehicle observing how the trailers react on real trails.
-Re: the shock setup and the notion that nothing will wear out other than the bushing, this is primarily an optical illusion due to the angle of the shocks. Because the shock are not mounted perfectly vertical travel is a factor of the axle travel. But, since our suspension actually flexes and is tuned for the weight of the trailer and since the axle slightly moved backwards when compressed, we get about 3/4 shock travel to axle travel. In other words, if the suspension is compressed 1 inch, the shock moves 3/4 inches. Plus, the shocks are pre-loaded allowing dampening even if a tire is off the ground.
-I spent quite a bit of money researching different shock manufacturers to get find the shock best tuned to the trailers. The red shocks in the Jeep giveaway have actually been replaced with a new set that we use. I contacted each major shock company describing our goal, weight, travel, etc. and we now use a shock that runs about $30.
-For those that have stated that our use of shocks is an advertising or aesthetic ploy, I can promise you they are not. Our trailers are each hand built after a one-on-one design process, using CAD, with our clients. If you have researched the off road trailer market you will know that our prices are near are on the low end while our components are on the high end. There is nothing on our trailers that is not primarily pragmatic and I would not spend the fab time, the cost of the shocks and mounting hardware if I was not positive it would improve our product.
Our trailers are tested in very harsh conditions. Last weekend we took an older prototype (without shocks) and ran Chinaman Gulch in Buena Vista, CO. This is considered a difficult trail (at least for non buggies) and we dragged the trailer across the entire trail. There are many videos on our side showing the obstacles we cross and how the the trailer fared. Also, our production trailers are significantly stronger and more heavily built than the proto in the videos.
Finally, we love Utah, got married there two years ago and I love visiting the state. For anyone in the CO Springs area, we let people "rent" one of trailers for free to test it out. If you wish to go camping and want to try out one of our trailers, shoot us a note. There is no cost.
Take Care and please let me know if you have any further questions.
Dave.
Here is a shot of our most recent design. Also not the bumpstop.
For lots of videos, check out our site.
Hi everyone -
My name is Dave Williams. I am the owner, designer, and builder PikesPeakTrailers.com. I saw references to our site from this website when looking at our web logs and decided to check it out.
The trailer being referenced is one that we built and was used as a giveaway. I am writing to address the use of shocks on trailers. My comments are specifically directed about the trailers we build which are designed to be taken off the highway. Our design characteristics and components we use have been tested over 10s of thousands of hwy miles and hundreds of trail miles. This include a variety of off conditions: rockcrawling, beach, fireroad, etc.
So, with this as a background, here is what I can tell you - for certain conditions the correct dampening system (shock) can make a tremendous difference in how a trailer behaves. Below are tested and observed facts, again specifically to our trailers.
-If the trailer is oversprung and does not flex, as many trailers are, shocks will not matter.
-Even when properly sprung to flex some when empty and more when loaded, hwy based travel does not benefit much from shocks as the bumps in the road are insignificant enough to cause much tracking disturbance or hop.
-By far, the biggest benefit we have seen to adding shocks is off road. The trailers are light enough so that, when used without shocks, hitting a large obstacle with a tire on one side can cause a severe pogo effect as the kinetic energy in the compressed spring fires back violently. This can cause the trailer, especially one side, to rebound and for the tire to get air. Proper dampening dramatically mitigates this.
-On washboard or other small tight terrain the effect is similar those understated. We have many hrs of video footage from a following vehicle observing how the trailers react on real trails.
-Re: the shock setup and the notion that nothing will wear out other than the bushing, this is primarily an optical illusion due to the angle of the shocks. Because the shock are not mounted perfectly vertical travel is a factor of the axle travel. But, since our suspension actually flexes and is tuned for the weight of the trailer and since the axle slightly moved backwards when compressed, we get about 3/4 shock travel to axle travel. In other words, if the suspension is compressed 1 inch, the shock moves 3/4 inches. Plus, the shocks are pre-loaded allowing dampening even if a tire is off the ground.
-I spent quite a bit of money researching different shock manufacturers to get find the shock best tuned to the trailers. The red shocks in the Jeep giveaway have actually been replaced with a new set that we use. I contacted each major shock company describing our goal, weight, travel, etc. and we now use a shock that runs about $30.
-For those that have stated that our use of shocks is an advertising or aesthetic ploy, I can promise you they are not. Our trailers are each hand built after a one-on-one design process, using CAD, with our clients. If you have researched the off road trailer market you will know that our prices are near are on the low end while our components are on the high end. There is nothing on our trailers that is not primarily pragmatic and I would not spend the fab time, the cost of the shocks and mounting hardware if I was not positive it would improve our product.
Our trailers are tested in very harsh conditions. Last weekend we took an older prototype (without shocks) and ran Chinaman Gulch in Buena Vista, CO. This is considered a difficult trail (at least for non buggies) and we dragged the trailer across the entire trail. There are many videos on our side showing the obstacles we cross and how the the trailer fared. Also, our production trailers are significantly stronger and more heavily built than the proto in the videos.
Finally, we love Utah, got married there two years ago and I love visiting the state. For anyone in the CO Springs area, we let people "rent" one of trailers for free to test it out. If you wish to go camping and want to try out one of our trailers, shoot us a note. There is no cost.
Take Care and please let me know if you have any further questions.
Dave.
Here is a shot of our most recent design. Also not the bumpstop.
For lots of videos, check out our site.
cowmilker
SUPER CHEESY
- Location
- Stansbury Park UT.
Is there anything to the fact that there is a "caster" effect on a "towed" vehicle? (really a physics question and I am not into physics too much) Think of a shopping cart with the front wheels that drag backwards, as compared to cart that has straight vertical pivoting wheels (think of the heavy duty carts at Home Depot).
- Location
- The Land Northward (Bountiful), Utah
I don't see a solid straight trailer axle having any caster. The spindles are welded on flat with the axle tube.
Most heavy vehicle straight axles have some camber so when loaded the are at or close to 0* camber.
Most heavy vehicle straight axles have some camber so when loaded the are at or close to 0* camber.
cowmilker
SUPER CHEESY
- Location
- Stansbury Park UT.
That's what I was talking about, I guess I got the two words mixed up. I was thinking "camber" was the angle of the wheel up/down (vertical alignment), and "caster" was where the center line of the wheel (spindle) as set back from the center line of the axle. Sorry if I was thinking backwards.
I was thinking in my mind that the physics would play out as if you were walking with a stick out in front of you and it hits a bump in the road it will catch or "hop", but if you are dragging the stick it will just "drag" over the bump.
I was thinking in my mind that the physics would play out as if you were walking with a stick out in front of you and it hits a bump in the road it will catch or "hop", but if you are dragging the stick it will just "drag" over the bump.
- Location
- The Land Northward (Bountiful), Utah
caster
camber
camber
but the stick isn't round on the end like a tire
cowmilker
SUPER CHEESY
- Location
- Stansbury Park UT.
oh yeah how did I miss that
cowmilker
SUPER CHEESY
- Location
- Stansbury Park UT.
OK children, Imagine (not a stick) a hand truck. When you are pushing it (positive caster) the shock from the bumps that the wheels are rolling over will be felt more stiffly than if you PULLED (like with a trailer you are PULLing) the same load on the same hand truck.
I realize that the axle it's self on the trailer may not have caster (trailer axle to trailer frame).
Perhaps "caster" is not the correct term. Maybe it's just "leverage".
Last edited:
- Location
- Sandy, Ut
OK parents
Caster nor camber is the correct term, as a hand truck absolutely has neither in any form of imagination. Leverage is more appropriate I suppose but I think what your trying to describe is the range of motion that the wheel/axle. The deflection and 'jerk' is effected by angle of deflection and tendency of motion.
Last edited:
cowmilker
SUPER CHEESY
- Location
- Stansbury Park UT.
OK parents
Caster nor camber is the correct term, as a hand truck absolutely has neither in any form of imagination. Leverage is more appropriate I suppose but I think what your trying to describe is the range of motion that the wheel/axle. The deflection and 'jerk' is effected by angle of deflection and tendency of motion.
"angle of deflection and tendency of motion" is more what I was trying to get to, but couldn't find the words, Thanks Cruiser.
TJDukit
I.Y.A.A.Y.A.S.
- Location
- Clearfield
Kurt, how'd you get to be so darn smart?
- Location
- Sandy, Ut
2INSANE, Webster Dictionary (big words) and Wiki
During my schooling (Mech. Engineering) I spent a considerable amount of time studying drivetrain, chassis and general automotive design. There are some great Chassis Engeineering text books for those wanting to see research basis and advanced chassis design including things like ackerman, scrub radius, etc. That and I'm good at b.s'ing
I'm good at b.s'ing[/FONT]
amen