Clearance question for my trailer build

[italianub]

I tried doing some searching and came up a little more confused. To be clear, I am not an automotive guy so forgive me if this question seems elementary.

How can you determine how high up your trailer frame is from the ground? I know there are lift kits to raise it, but if you build a trailer frame and put a leaf spring axle on it, is it purely the tire size that will determine the distance between the ground and the frame? What are ways to lower or raise it?

Thanks for any info you guys can provide, this forum has made me so much more confident in my upcoming build. While I am sure I'll have more questions come 2024 when I begin, this is an area that I am very unfamiliar with.

[Pmullen503]

Ground clearance is basically half the tire diameter if you use leaf springs. The axle will always be the lowest part no matter how high the frame is.

If the goal is to get the frame higher (so the frame won't scrape turning into a steep driveway for example), you could add taller leaf spring mounts.

If what you want is ground clearance for off road travel, then you want half axle type suspension.

[italianub]

Ground clearance is basically half the tire diameter if you use leaf springs. The axle will always be the lowest part no matter how high the frame is.

If the goal is to get the frame higher (so the frame won't scrape turning into a steep driveway for example), you could add taller leaf spring mounts.

If what you want is ground clearance for off road travel, then you want half axle type suspension.

Thanks for this info! So for example, if I am using 265/70R16 tires on my truck, this means the tire has a height of 2.75 inches and rims are 16 inches, so the clearance would be half of 19.75 inches (9.875 inches). Does that sound right?

Seems pretty low, so maybe I should get the trailer leaf spring mounts to raise it up. As you can see in this photo, my truck's hitch starts at about 14.5 inches from the ground, center is around 16 inches (not lifted), so I would imagine I should bring the trailer up a little. But how much?

[TimC]

One method many of us have used is to mount the axle over the springs rather than under the springs. I'm no expert on the matter but I was advised to install larger, stronger U-bolts instead of using the ones included with the kit trailers I have purchased. Installing over the springs will effectively lower the trailer bed by a few inches. Note: some axles will not allow for this method but may be modified.

[QueticoBill]

Your 9 or so inches to axel is more clearance than my Outback. I don't think you need to raise it more. I have 12" tires and underslung the axel as Tim suggested, and no problem.

The hitch just requires the right ball mount for a level frame.

[Pmullen503]

For aerodynamics and stability it's generally better to keep the trailer frame as low as practical. If you need off road ground clearance use taller tires and half axles. You can get a drop hitch mount to match the truck receiver and trailer height. You want the frame to be more or less level while towing.

[Sparksalot]

Larger tires and flipping the axle relative to the springs can do wonders. For my tear, the combination of the two gave 5” of change to the ride height.

Before with 25” tall tires.



Before with 27” tires.



After with 27” tires.





Axle before and after flipping.

[italianub]

Thanks everyone! I understand things much better now

[Onajourney]

I you want the most true clearance, go with axless torsion axels.

[Squigie]

The axle manufacturer should have spec sheets for their products.
You can use those dimensions and tire diameter to estimate ground clearance and frame height.


With Timbren axle-less suspension and ~26" tall tires, I believe I am at 19.75" for frame height. Should work well with my truck and other models in the class. Slight nose-down angle to the trailer frame with ~300 lb of gear slightly squatting the truck.