Rim offset safety

[Oli]

Hi All,
I am new to the forum.
I've been dreaming of building a teardrop for the last 3-4 years.
I've finally been able to scrounge up enough to start my build (and convince my wife).
I'll be welding my own trailer frame and plan to try and use some 15" honda alloy rims I was able to acquire for a good deal.
I plan to buy a 2K straight leaf spring axel online.
I plan to mostly drive on pavement but may stray to some tame dirt roads. (no 4x4/rough dirt roads/trails).
I've been trying to understand tire offsets but haven't been able to find much on safety/advisability in regards to auto rims on a trailer.
My rims have a 6.76" offset from the hub face to tire face (distance A). I assume I'll want at least a 0.25" gap (probably more) between the tire and the frame (distance C).
That leads my to assume that my axle will protrude 7"+ past the leaf spring.
My inner engineering sense are a little tingly at the thought of 7"+ of axle unsupported.
I wanted to check if others have done something similar? any precautions I should take?
Am just overthinking this?
I really don't want to head down the road with my newly finished teardrop only to have an bear fail or have my axel bend from hitting a small bump.

Thanks in advance for any thoughts/ideas/tips/insights.
I'll most likely be back with more questions as I continue my build.

Oli

[Tom&Shelly]

Welcome to the forum!

Tom

[tony.latham]

I'll want at least a 0.25" gap (probably more) between the tire and the frame (distance C).

As you know, the tires will be significantly wider than the rims, and you'll want a gap wider than 1/4".



I don't know the minimum distance you can get away with, but an inch might be about right.



Do those rims have a hole for the axle hub to stick out of?





Tony

[Squigie]

7" of unsupported axle seems fine.
But you could reduce that by going to a wheel with zero or negative offset (less backspacing) and a narrower axle.

You'll want more than 1/4" of clearance between tire and frame.
Things to remember:
The tire is nearly always wider than the rim.
The tire will flex and wobble on the road (bumps, dips, potholes, etc.).
The axle does not travel straight up and down. The axle can tilt. Each side will move in an arc at times.
Leaf springs flex sideways and have some movement in their bushings and shackles.
Roads have debris. You need room for mud, gravel, and stray bits of pallets to pass through without gouging the frame, fender, or tire. --Or getting stuck and catching fire. (Yep. I've seen that.)

My suspension setup is totally different, with minimal tilt/lean or side play; I am using steel wheels from a ~'74 Oldsmobile (close to zero offset); and my trailer is intended for rough road use. But what I settled on, with the exact tire that I will be using, was 1" of clearance, minimum. With leaf springs, I'd be looking for more like 1.5-2" (but, again, with rough roads in mind).
I don't have my 'design' binder handy, or I could show the drawings where I worked it out.

If you settle for 1" of clearance, keep in mind a way to correct any tendency for the axle to shift to one side. 1/4" on one side and 1-3/4" on the other side isn't helpful.

[gudmund]

Honda rims would mean a Honda lug size pattern = Question? does anyone in the trailer industry use or make trailer hubs with a Honda sized lug pattern?? or does this mean you will also be using hub adapters for the matting? If so, won't this have to also be figured into the offset measurement for rim spacing?

[Oli]

Thanks for the feedback, it's helped quiet some of my worries slightly and given me some confidence to move forward

@tony
I checked first thing when i got home and my rims do have a hole that should accommodate a hub "nub".
I double checked by measuring the diameter of the "nub" an a small utility trailer I have and making sure my rims could clear that with room to spare.

@Squigie
I've been keeping an eye out for 0/near 0 offset but haven't seed any available used(and within my budget) sadly
I have 4 of my honda rims with tires, so 2 for the road and 2 spares (one of the reasons why I went with these)
Sounds like I'll shoot for around 1"-1.25" on each side for clearance between tire and frame.

@gudmund
These rims have a 5X4.5 lug spacing which I've seen is pretty common on trailer axles.

[gudmund]

I did not know what Honda's mounting dia. was? would have thought they would have been metric sized (but, did just find out that Toyota is "still" using the GM-Chev 5.5 inch dia. for their 6 lug sizing on their Tacoma PU's today - knew years ago they had been using it) the common 4.5 inch trailer sizing being used today is what Ford/Crysler have used for years. And yes, the center hole is the other thing to be concerned about. Example: on my last 2 Chev Colorado's -07/12- they both used the same 6 hole pattern/size as GM's full sized PU's, 5.5in dia 6 lug pattern -BUT- it was the center hole that was different = the full sized PU's used a smaller center hole than mine, so they would not fit on my Colorado's - now I own one a '22 Colorado which still is a 6 hole pattern -but- is now a120mm dia. 6 hole pattern which will not fit the Full Sized ones at all. Now for the 'new' added change, the '23 Colorado model re-design = they have now 'standardized' the Colorado with their Full Sized PU's = making all of their wheels inter-changeable = and yes = they are still using the GM 5.5 inch dia. 6 bolt lug pattern they have been using on their 1/2 ton PU's since the mid-19thirty's.............

PS I just measured the space between my tire side wall/frame which is about 1.5+ inches on each side. This is a factory built frame using leaf springs with a 3500 lb axle. I am thinking you may need just a bit more room between the tire & frame with a leaf-spring set-up being there would be more of a tendency for needing a bit more space for the 'twisting & flexing' with a axle/leaf spring setup. I do remember my old trailer, which had the Dexter torsion set-up having less space - barely about one inch of space on each side between the tire/frame, that set-up basically is a swing arm that 'hinges' straight up and down when moving during operation 'totally separate' from the other side = keeping the tire perpendicular with the trailer at all times without any side flexing/movement being for the most part, as the road shock is absorbed by the axle 'twisting inside' a rubber compressed inset and the flexing of the tire itself - each side works totally separate of the other........... I am thinking a leaf-spring set-up needs to have a-bit more room on each side being the whole set-up moves around as 'single unit'