trailer height question with timbren axle-less suspension

[italianub]

I've decided on Timbren's axle-less suspension and I've got some more clearance/height questions regarding two options from them and I want to see if you guys think my math is accurate before I end up purchasing. Full disclosure, I am only even considering the 4" lift version after speaking with the lady on the phone, she made me second guess my measurements (out of caution, and I am glad she did), and therefore I am asking you guys here! For reference, I am planning on using the same tires as my truck, which are 265/70R16

Option 1: ASR1THDS02 (Timbren Axle-Less Trailer Suspension - Heavy Duty - Long Spindle w/ No Drop)
From center spindle to the bottom of the trailer frame is 5.3" and my tires are 30.6" tall (15.3" from center to ground). I will have an A-frame underneath which is 3" in height, so my coupler should be at 17.6" from the ground, does this sound accurate? 5.3" (spindle to bottom of the frame) + 15.3" (tires) - 3" (a-frame up front) = 17.6" The frame from the ground to the bottom of the trailer frame at the wheel will be 20.6" and 17.6" from the trailer frame at the front

Option 2: ASR1THDS03 (Timbren Axle-Less Trailer Suspension - Heavy Duty - Long Spindle w/ 4" Lift)
From center spindle to the bottom of the trailer frame is 9.125" and my tires are 30.6" tall (15.3" from center to ground). I will have an A-frame underneath which is 3" in height, so my coupler should be at 21.425" from the ground, does this sound accurate? 9.125" (spindle to bottom of the frame) + 15.3" (tires) - 3" (a-frame up front) = 21.425" The frame from the ground to the bottom of the trailer frame at the wheel will be 24.425." and 21.425" from the trailer frame at the front

Currently, from ground to the center of my truck's hitch is 16" and is also 16" with the current ball setup I have, so I think the 4" lift is completely out of the question (which I am completely fine with), but I wanted to verify my math with you guys before I pull the trigger. I understand weight will lower the overall height, and assuming I go with the "No Drop" version of the suspension, it might align with my 16" hitch/ball. After typing all these measurements up, I just realized that I need to take that front A-frame into consideration, so in theory it might be 3" higher than the 17.6" with No Drop since the coupler sits on top of the A-frame... so 20.6" and 24.425" depending on which one I go with.

Should I just do the 4" drop instead? Lowering the overall height to around 16.6" but that seems pretty low

[Squigie]

Got your DM.

I think you've got it right, but just want to make sure with a visual.
Is this what you have in mind for the A-frame and coupler?

Edit: Oof. Sorry. Didn't realize that sketch was so wide.

timbrensketch.png (22.62 KiB) Viewed 226 times

Feel free to edit, if anyone wants to doodle on it.

Two (and a half?) things to keep in mind:
-If you're measuring to the center of the hitch ball, you should also measure to the center of the coupler.
-Tires will probably squat about 3/4", possibly a little less, if aired up to a pressure appropriate for the trailer's final weight and payload. While we do use full radius/diameter for many tire calculations, tire squat should be considered, if not included, for static height calculations.
-Have you considered what these various heights would do to fender height and fender length at floor height? Interference with other plans, or getting too close to the door(s), should be checked out. (But everyone's plans are different and it may be no-factor in your case.)

[italianub]

Is this what you have in mind for the A-frame and coupler?

Yessir!

-If you're measuring to the center of the hitch ball, you should also measure to the center of the coupler.

here's the photo i took!

-Tires will probably squat about 3/4", possibly a little less, if aired up to a pressure appropriate for the trailer's final weight and payload. While we do use full radius/diameter for many tire calculations, tire squat should be considered, if not included, for static height calculations.
-Have you considered what these various heights would do to fender height and fender length at floor height? Interference with other plans, or getting too close to the door(s), should be checked out. (But everyone's plans are different and it may be no-factor in your case.)

The fenders will be custom like the rest of the trailer, so I am not worried at all about the fenders. I am mostly just concerned with the height of the trailer vs height of my hitch (I know I can get hitches that are below/above the current ball, but I also don't want the trailer to be too tall)

[Squigie]

I think you need to figure out what your coupler height will be, and go from there.

[KCStudly]

... also, don't forget that the trailer chassis can be level or a couple inches down at the front for best handling of the tow vehicle, so allowing a little extra height at the axle is better than having the hitch ball too high. And, with a receiver hitch like yours, you can get different ball height draw bars and/or flip the ball on the draw bar for different ball heights... assuming everything still clears the TV.