Tire Clearance (Pics)

[eagle24]

I guess if I ask 10 people I'll get 10 different answers, but what are your opinions on my tire clearance?

Frame is 60" wide and will have 1/4" outside plywood lapped over it, so trailer will finish 60-1/2".

Tires are pretty big. P235 75/R15 Actual backset measures 4-5/8".


Here's the skinny. If I use a 72" hub face to hub face axle, I'll have 1-1/8" clearance between tire and trailer side. Debating on whether I should have the axle built 74" to give me 2-1/8" clearance.
3500# axle with 2000# leaf springs and shocks. What do you think?

[Ottsville]

From what I've been reading around here and other forums, 2" seems to be the rule of thumb. I like those wheels - do they clear the hub without a spacer?

[Ottsville]

Thinking more about those tires, with those you're probably going to be going off-road some, no? 2" would give better clearance when those tires are covered in mud and picking up gravel thus protecting your sides more

[eagle24]

From what I've been reading around here and other forums, 2" seems to be the rule of thumb. I like those wheels - do they clear the hub without a spacer?

Yes, they do not require a spacer. I'm trying to get the axle right, so I don't have to use spacers, but I would also like to keep them as close to the trailer as I can. They are wide, and with 2" space from trailer, I'll need 12" fenders minimum for total coverage. Also, the track on this trailer is already 6" wider than my Tacoma, but that's not a huge deal. I'll probably like being able to see it better from my side mirrors.

Greg

[eagle24]

Thinking more about those tires, with those you're probably going to be going off-road some, no? 2" would give better clearance when those tires are covered in mud and picking up gravel thus protecting your sides more

I know the spots I'll likely use it off-road. They aren't very bad, and no mud. More than anything, I just like the look off the off-road trailers, and I do like that they are built tough. Kinda silly, but I think a off-road trailer will look cooler behind my Tacoma 4x4. I'm still kinda leaning to a 74" axle. 1" clearance is cutting it a little close.

[KTM_Guy]

I'll be 1.5" on mine. I have searched and didn't come up with any hard number that made any sense. I saw more on keeping the trailer tire width the same as the TV so they will track in the same line. More for hardcore off roading.

My concern with clearance is with mud. We can get this thick sticky mud that could build up can cause a clearance problem. It is the worst on a motorcycle have come across it in the jeep yet.

I'll leave room with the fenders to add an adapter later if I really need to.

Todd

[working on it]

...Here's the skinny. If I use a 72" hub face to hub face axle, I'll have 1-1/8" clearance between tire and trailer side. Debating on whether I should have the axle built 74" to give me 2-1/8" clearance.
3500# axle with 2000# leaf springs and shocks. What do you think?

• I've gone from having about 1.5-1.75" clearance, to about 3", and back down to 2+"...and my suspension has built-in safeguards to stop contact; in your case, why not get the extra width, just to be sure, as long as the outside width of your tires doesn't become a problem?
• A leaf-spring axle, whether located front or rear on a car or truck (called a solid-axle on 4wd's & heavy trucks), or on a trailer, will cause one wheel to pivot up closer to the frame (or conversely, the fender lip on the other side), creating a fitment issue. If that see-saw effect isn't limited via a positive stop, or super-firm springs. then some tire scrub against frame or fender can be expected, especially on very uneven roads or trails. Independently-sprung tires (on IFS front suspensions on cars/trucks, torsion and Timbren-type suspensions on trailers), do not have the same problem. And, tire size, type, and section width also can increase the need for proper fitment, to avoid tire contact.
• Tire sidewalls flex under load, sometimes moving toward a contact point, so the elimination of such contact requires spacing your tire so that the sidewall bulge (at the section width measurement point) doesn't come close enough. On the frame side, under most conditions, a properly-inflated tire doesn't need more than .75-1", but on fire-roads or trails, that requires more spacing, depending on: tire characteristics, proper or under-inflation, axle travel, and bumpstop or axle limiters that can prevent contact. On the fender side (low-riders need not apply), the taller/wider (more open) types of fenders on most trailers and trail-following tow vehicles, are already mostly safe from tire contact.
• My original axle was noticeably inferior to what I wanted/needed to make my TTT able to traverse even mildly-challenging roads; I didn't have the budget at that time, for my axle of choice, so I just added wheel spacers to fit wider/taller tires under my selected fenders (good for 14-16" tires, as advertised), at least for the interim. I went from 8" to 14" tires, so it was a necessity to install the fenders/spacers, ASAP. When I finally upgraded the suspension, I got a wider axle (a requirement to fit in brakes), which eliminated the need for spacers, and also gave me more clearance between tires and frame, and the fenders still had sufficient clearance. too. The tire-frame clearance more than doubled, and that was a great boon, because I later added taller/wider/more flexible LT tires, in place of the rigid-sidewall ST bias tires I had used previously. I still retained about 2" clearance, but I did have to add fender flares to cover the outside tread, though no clearance issue with the fender was caused by the bigger tire. So, I have quite adequate clearance, all around.

• 

  tire distance from trailer.JPG (114.25 KiB) Viewed 727 times

  original tires, in both pictures
• Though I intended my squareback trailer for adventuring, someday, it's now becoming clear that it probably won't happen, at least by me, with this trailer. I'm getting too old, and with some infirmities, that make solo camping/adventuring something I should've started 20+ years ago; my TTT doesn't need any more suspension tweaks, as it is already overkill for the roads I'll travel on...but maybe not, if ever I get the right TV, and a "caretaker", or fellow camper, to go along, and look out for the old guy?

[eagle24]

...Here's the skinny. If I use a 72" hub face to hub face axle, I'll have 1-1/8" clearance between tire and trailer side. Debating on whether I should have the axle built 74" to give me 2-1/8" clearance.
3500# axle with 2000# leaf springs and shocks. What do you think?

• I've gone from having about 1.5-1.75" clearance, to about 3", and back down to 2+"...and my suspension has built-in safeguards to stop contact; in your case, why not get the extra width, just to be sure, as long as the outside width of your tires doesn't become a problem?
• A leaf-spring axle, whether located front or rear on a car or truck (called a solid-axle on 4wd's & heavy trucks), or on a trailer, will cause one wheel to pivot up closer to the frame (or conversely, the fender lip on the other side), creating a fitment issue. If that see-saw effect isn't limited via a positive stop, or super-firm springs. then some tire scrub against frame or fender can be expected, especially on very uneven roads or trails. Independently-sprung tires (on IFS front suspensions on cars/trucks, torsion and Timbren-type suspensions on trailers), do not have the same problem. And, tire size, type, and section width also can increase the need for proper fitment, to avoid tire contact.
• Tire sidewalls flex under load, sometimes moving toward a contact point, so the elimination of such contact requires spacing your tire so that the sidewall bulge (at the section width measurement point) doesn't come close enough. On the frame side, under most conditions, a properly-inflated tire doesn't need more than .75-1", but on fire-roads or trails, that requires more spacing, depending on: tire characteristics, proper or under-inflation, axle travel, and bumpstop or axle limiters that can prevent contact. On the fender side (low-riders need not apply), the taller/wider (more open) types of fenders on most trailers and trail-following tow vehicles, are already mostly safe from tire contact.
• My original axle was noticeably inferior to what I wanted/needed to make my TTT able to traverse even mildly-challenging roads; I didn't have the budget at that time, for my axle of choice, so I just added wheel spacers to fit wider/taller tires under my selected fenders (good for 14-16" tires, as advertised), at least for the interim. I went from 8" to 14" tires, so it was a necessity to install the fenders/spacers, ASAP. When I finally upgraded the suspension, I got a wider axle (a requirement to fit in brakes), which eliminated the need for spacers, and also gave me more clearance between tires and frame, and the fenders still had sufficient clearance. too. The tire-frame clearance more than doubled, and that was a great boon, because I later added taller/wider/more flexible LT tires, in place of the rigid-sidewall ST bias tires I had used previously. I still retained about 2" clearance, but I did have to add fender flares to cover the outside tread, though no clearance issue with the fender was caused by the bigger tire. So, I have quite adequate clearance, all around.
• tire distance from trailer.JPG
  original tires, in both pictures
• Though I intended my squareback trailer for adventuring, someday, it's now becoming clear that it probably won't happen, at least by me, with this trailer. I'm getting too old, and with some infirmities, that make solo camping/adventuring something I should've started 20+ years ago; my TTT doesn't need any more suspension tweaks, as it is already overkill for the roads I'll travel on...but maybe not, if ever I get the right TV, and a "caretaker", or fellow camper, to go along, and look out for the old guy?

Good Stuff! Thanks man! 74" axle will give me 2-1/8" clearance. I'll go with that. Got all the welding done on the frame this afternoon except the A bracing for the tongue and I have to weld on the 2" hitch receiver.