Help me figure an axle length for my m416 trailer

[Flashole]

The trailer frame is 41" wide.
My wheel backspacing is 3.75"
It looks like the tire bulges over the wheel rim by about 1.5" when it's fully inflated. I would assume that it would bulge over a little more when aired down for off roading.
My question would be, how much space between the tire and trailer frame would be adequate? 1-4"? More???

I'm thinking 60" or 61" would be about right, but I'm not 100% confident. So, I'd like to get a couple other opinions before making a purchase.

ETA......The original axle is 57".

 

[Flashole]

94 views, a forum full of expert builders and not a single response. Surely somebody has an answer, or at least an opinion:av-7: I have no idea what that smiley is about, so i thought I'd use it:ylsmoke:

 

[tdittyrocks]

Im not sure what the backspacing on the original wheels are, but lets say they are 0" and the tire does not protrude from the rim. A 61" axle width would give you close to the original clearance of the stock wheel/tire combo given the specs you provided.

 

[Flashole]

It's not zero, it's actually more like 5". Not what I expected really.

Now I'm thinking the stock size of 57" should be about right.

41" Trailer width
4" back spacing on each wheel.
2" Tire bulge on each side
2" clearance on each side.

 

[FredB]

I used a 62" axle, I'm fairly sure. I thought it was amusing since stock XJ axles are about 60". This is with a spring over to fit 33x12.5"-15 on wheels with 5.25" backspacing. The tub on my M416 was widened 3". There is room in case a miracle happened and the trailer flexed over an obstacle. Not saying it won't, but I've yet to see it.

 

[FredB]

Here's a pic.

 

[Flashole]

I used a 62" axle, I'm fairly sure. I thought it was amusing since stock XJ axles are about 60". This is with a spring over to fit 33x12.5"-15 on wheels with 5.25" backspacing. The tub on my M416 was widened 3". There is room in case a miracle happened and the trailer flexed over an obstacle. Not saying it won't, but I've yet to see it.

So your tub is 3" wider, but you have 2.5" more backspacing over all. So you have approximately .5" more over hang or clearance than I would have with a 57" axle. I'm still thinking 57" would be about perfect.