My race car is low with the splitter on. My trailer is very traditional open deck steel. The loading process isn't awful, but it does require lumber and race ramps plus splittter removal. I have another, older open deck I could easily bring myself to modify.
Any experience converting to a bagged system?
It seems like not a huge job at a glance. Glass half full?
Definitely watching this
One place to look for air bag trailer systems is e-trailer.
That being said, I tried to find the same thing you are looking for on our camper, and had a pretty tough time. One of the tricky parts is that the adjustable air bag systems for cars are not as strong as the spring rates you need on a trailer. There are a lot of trailer air bag systems out there- hard to figure which is best.
The other thought would be to get one or two solid torsion axles and then make a pivot system to raise and lower it. That's the system that was used for a trailer that has been brought up on this forum a few times. My issue was that I could not figure a mechanism that I could fit under a camper and still access it. But with a open trailer, it's more a matter of building a strong and lockable 4 bar mechanism that you can change the angle of the axles.
You can also go a different route and try to just lower the deck of the trailer so that the approach angle is easier to deal with. And there are a number of independently mounted systems- where each wheel/axle attachments are not connected to each other. Which should make it possible to raise the point where the wheel ends up so that it's much higher up and the trailer bed ends up lower.
And a simpler version of that is to go dual axle with short wheels. Doesn't gain a lot, but anything would help, I suppose.
Have you ever seen the Sloan Kwik-Load trailer? I had one and it worked great for a low car. I sold it to my brother 10 years ago and he still uses it.
My old GMC motorhome had air bags and 4 rear wheels, this system was bolted to a traditional frame. The load on the back end was probably 6000 pounds. May be tough to find but this might work. Plus there are disk conversion kits available.
alfadriver said:
The other thought would be to get one or two solid torsion axles and then make a pivot system to raise and lower it. That's the system that was used for a trailer that has been brought up on this forum a few times. My issue was that I could not figure a mechanism that I could fit under a camper and still access it. But with a open trailer, it's more a matter of building a strong and lockable 4 bar mechanism that you can change the angle of the axles.
OK...this has my gears turning. I had airbags on my Mercedes E350 wagon and deleted them for coilovers when I started getting slow leaks...I just didn't want to deal with that as a maintenance item. I like the idea of mechanical over air really in the end...so I like this approach a lot. I'm going to be thinking about this and maybe use my old 944 parts as something to ponder with. Four independent cams to raise and lower would work, but the force to do that with a car on it would be something to overcome. This is a good mental exercise. Thank you.
porschenut said:My old GMC motorhome had air bags and 4 rear wheels, this system was bolted to a traditional frame. The load on the back end was probably 6000 pounds. May be tough to find but this might work. Plus there are disk conversion kits available.
I have bags on my Wanderlodge...they work really well for the bus. The system is gigantic, so it would be complete overkill unless I had a large enclosed trailer. But that's good food for thought.
How low does the deck need to be to load without removing the splitter? An air bag system will only allow the trailer frame to drop as far as the top side of the axles. That same height is attainable with torsion axles fairly easily. If you need even lower deck height you'll be looking at a system that allows the center point of the wheels to rotate up past the frame rail, or restructuring the frame rails (think along the lines of a C-notch in a truck frame), or using drop axles. I built a trailer once-upon-a-time for a Formula Vee that had an eight inch deck height. Made my own axles with a big drop and basically ran it without any suspension, just a center pivot between the axles.
Edit: I have seen a trailer where the deck isn't level, too. It was built like a shallow ramp truck with some slope to the deck but not to the suspension and the dove tail was much closer to the road.
A couple thoughts, check out this video for what some random guy on the internet did: https://youtu.be/5dRU-3YiAsE
also, some of the off-road trailer companies make independent swing arm suspensions and I think some are available as kits, here is an option from timbren https://timbren.com/n-117-how-to-build-a-better-off-road-trailer-suspension.html
it seems like independent suspension is necessary to get low enough
$.02
I've been wanting to do the same with my gooseneck for the same reasons of loading and unloading a low car.
My working plan (if I ever get around to it) is to keep the solid axles of the trailer but convert from leaf springs to semi air bags on sing arm setup (think NASCAR truck arm). It would require that the arms be off to the inner side of the frame to allow for the air bags to have an upper mount just below the deck and solidly attached to the frame. If i gave the frame a small C notch I'd be able to lay the fenders on top of the tires with a 4-5" drop when loading/unloading. I'd still need to remove the splitter but not having the transmission and exhaust hit every time would be nice.
In reply to mechanicalmeanderings :
Thanks for that link. Interesting videos and since I'm originally from Quebec I found the guys' accent familiar and kind of comforting.
DeadSkunk (Warren) said:In reply to mechanicalmeanderings :
Thanks for that link. Interesting videos and since I'm originally from Quebec I found the guys accent familiar and kind of comforting.
Viny B would definitely be a GRMer. He has also built a motorcycle engined smart car that features a homebuilt lockable chain drive diff. Great videos too.
lotusseven7 (Forum Supporter) said:Have you ever seen the Sloan Kwik-Load trailer? I had one and it worked great for a low car. I sold it to my brother 10 years ago and he still uses it.
I have used one a long time ago that did this kinda thing too. About a year ago I spent a lot of time looking for how the mechanism worked (the sliding part) and couldn't find much. I was considering building my own. Any ideas of how it works?
I bought plans from fab plans on their airbag trailer. It wasn't that expensive and if you already have a deck you could probably incorporate the air suspension plans reasonably.
Robbie (Forum Supporter) said:lotusseven7 (Forum Supporter) said:Have you ever seen the Sloan Kwik-Load trailer? I had one and it worked great for a low car. I sold it to my brother 10 years ago and he still uses it.
I have used one a long time ago that did this kinda thing too. About a year ago I spent a lot of time looking for how the mechanism worked (the sliding part) and couldn't find much. I was considering building my own. Any ideas of how it works?
Looks like a pretty simple subframe for the axles- pretty darned clever design. I think I would add an electric winch to make loading a little easier.
When you see the video, it appears that the tilt part is actually built into the bed frame, so that as it slides back, there's always a flat sufrace (mostly) to slide against.
My recommendation to anyone thinking of things like this is to actually do the math on the angles and such involved. Think of your realistic limits. Ie, if the tire is 25 inches tall, and you have solid axles, then you aren't getting lower than 13 inches at the rear axle, which may only be 6-8 feet from the rear of the trailer.
If you have a 1/6 rise/run, you still need to have the front of the splitter 4 inches above the ground if the front overhang from your front wheel center is 24 inches. And keep in mind all of the above is in perfect scenarios. Real world will be worse! And don't forget, then the front of the trailer (which could be 10-15 feet in front of the rear axle), would also need to go up 2-3 feet to achieve the overall deck angle - how are you going to do that?
The resolution that I came to before is that it just isn't worth it to try and modify an existing trailer. Just sell the existing one and buy the one that does what you want. It would be hard to do the modification for less than any difference in cost.
alfadriver said:Robbie (Forum Supporter) said:lotusseven7 (Forum Supporter) said:Have you ever seen the Sloan Kwik-Load trailer? I had one and it worked great for a low car. I sold it to my brother 10 years ago and he still uses it.
I have used one a long time ago that did this kinda thing too. About a year ago I spent a lot of time looking for how the mechanism worked (the sliding part) and couldn't find much. I was considering building my own. Any ideas of how it works?
Looks like a pretty simple subframe for the axles- pretty darned clever design. I think I would add an electric winch to make loading a little easier.
When you see the video, it appears that the tilt part is actually built into the bed frame, so that as it slides back, there's always a flat sufrace (mostly) to slide against.
yeah, but does it use rollers? some type of bearing? Or is it just large greased metal drawer slides? How is it located laterally while towing but also prevented from binding when sliding? Trailer brakes appear to be hydraulic.... do they just have super long rubber lines? Maybe the brakes to slide are separate from the brakes to drive with?
I use one of these trailers on the regular and we have out all sorts of really low cars on it without a problem. I know you said you already have a couple trailers so this may not be what you are looking for but it's a nice trailer.
Brimar
PM me if you want more info on the air bag trailer plans.
Nick
In reply to New York Nick :
This is essentially what I had in my head. Take my open trailer, find a parts source for the axles and bags.
The options have opened up in my mind ( expected from this group) so now I'm pondering some way of taking 944 torsen axles and figuring a way to rotate the axle center on a swing arm, pivoting the wheel up and the deck down.
I agree that I could sell what I have and buy a thing that already does this, but I enjoy cobbling stuff together.
To get a better angle can you just use longer ramps and brace them in the middle with a block........
If you have an extra axle, where the ends are still good- google "axle less trailer suspension" and see if you can fabricate one of those. The ones I see on e-trailer look as if a design like that could use a heavy duty air bag. Although, it ends up looking much like the DIY trailer air bag that was posted already.
I understand wanting to build your own. I'm the same way. I thought I remembered seeing a trailer that had cables to lower the torsion axles to load and unload but I couldn't find it. I did find these while I was looking though. It may give some inspiration.
https://www.futuratrailers.com/us/pro-sport
I went with the Lippert air suspension from e-trailer when I upgraded the axles in my 26' enclosed car trailer, hopefully to gain a couple inches of drop/rise. Quality ok, design not so much, stupid expensive 
I guess it helps with load capacity; I felt no difference in ride. But the biggest disappointment is from minimum air to max of 110 psi is about 1/2"of ride height delta!
way too much money. Cannot recommend.
New York Nick said:I understand wanting to build your own. I'm the same way. I thought I remembered seeing a trailer that had cables to lower the torsion axles to load and unload but I couldn't find it. I did find these while I was looking though. It may give some inspiration.
https://www.futuratrailers.com/us/pro-sport
My friend Matt is on their endorsement reel....I know this trailer a bit and it is impressive. Watching him load and unload his e46 race car is one of the reasons I'd like to have a lower, slicker solution!
https://www.knott-trailer-shop.com/catalogs/Trailer_Lowering_Systems.pdf
this embodies some of the conversations here.
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