Axle placement

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Re: Axle placement

Postby working on it » Sun Apr 04, 2021 4:43 pm

Shadow Catcher wrote:...Our axle was too far back and has been replaced and moved forward.


* On mine, the axle started at 40r/60f, but I added 24" on the rear, and 12" onto the front, bringing it to around 45r/55f. Not inherently bad, until I crammed the rear "galley" with heavy items (water jug), Coleman equipment, A/C unit, and a generator, and only had a spare tire and a battery box on the tongue to balance it with.

* As it was, I only had around 40 lbs tongue upon weighing and first trip (kept controllable by using a Weight Distributing Hitch I modified, and by loading two Aquatainers and a large, filled, cooler inside the cabin, strapped to the front wall). At only 3.2% tongue weight/total weight, it made me wish I had added more length forward instead of rearward.

* After the first trip, I added a real tongue box, put the battery, extension cords, plugs, and misc. spares into it, but still carried the same front-loaded weight to compensate for the heavy rear load for several more years. During this time, I had a chance to correct the balance ratio, when installing a completely new suspension, but having welded the fenders so firmly in place, I didn't want to have to relocate them....

* In 2015, I finally added a rack over the tongue box, to carry canopies (100 lbs canopy weight, plus rack weight 20 lbs), which helped shift the balance forward enough to remove the water and cooler from inside the cabin for travel. I put my 100 lb food pantry box inside (no liquids to spill) for a couple of trips. and then decided to make a second rack under the first. That done, the balancing act was accomplished, and with nothing to remove from the cabin for quick set up at camp.

* Since then, I added about 25 lbs of fishing gear (rods, reels, storage tube) on the roof, removed some weight from the rear, and added some to the tongue; the 12% balance works so well, I can finally tow without worry, even using the ball coupler alone, w/o weight distributing hitch hooked up.
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moving wt forward to achieve proper weight balance.jpg
moving wt forward to achieve proper weight balance.jpg (424 KiB) Viewed 1063 times
2013 HHRv "squareback/squaredrop", rugged, 4x8 TTT, 2225 lbs
  • *3500 lb Dexter EZ-Lube braked axle, 3000 lb.springs, active-progressive bumpstop suspension
  • *27 x 8.5-14LT AT tires (x 3) *Weight Distribution system for single-beam tongue
  • *100% LED's & GFCI outlets, 3x fans, AM/FM/CD/Aux. *A/C & heat, Optima AGM, inverter & charger(s)
  • *extended-run, on-board, 2500w generator *Coleman dual-fuel stove & lantern, Ikea grill, vintage skillet
  • *zinc/stainless front & side racks *98"L x 6" diameter rod & reel carrier tube on roof
173193172890148599
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Re: Axle placement

Postby bobhenry » Tue Apr 06, 2021 5:37 am

THERE MIGHT BE A BIT OF CONFUSION ABOUT THIS THREAD. THE 60/40 OR 65/35 RULE IS WITH THE BODY ONLY. Tongue length has no bearing on this rule.
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Re: Axle placement

Postby John61CT » Tue Apr 06, 2021 8:14 am

The only point of these guidelines (not "rules") is to get the ball weight right

Ideally close to ~10% of the trailer total, say 8% to 12% at the extremes.

If your placement of the densest contents means that the axle placement needs to be different, so be it.

However, the other guidelines are, most weight should be at a low COG and

clustered between the wheels near the axle(s).

And a longer tongue (really distance from ball to axle) is better than shorter.

The closer the total trailer weight gets to that of the TV, and the higher the driving speeds are, the more critical these rules are to driving safety.

IOW a very heavy TV with a light trailer is much better than v/v.

But just driving slower can compensate a lot too.
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Re: Axle placement

Postby DrewsBrews » Tue Apr 06, 2021 8:17 am

lfhoward posted this when I inquired about placement. I found it very helpful, though there is a bit of a learning curve figuring out exactly what all the values are for. I found the most odd one to be the tongue weight % you input is the actual weight of the tongue bar compared to the weight of the trailer... a bit confusing (to me at least).

https://www.engineersedge.com/calculato ... alance.htm


In my case 46" from the back of 120" cabin seemed like a good spot when playing around with loading weights along with estimated galley weight. That ends up as about 38/62 by my calculation. Im working on a squaredrop with storage space under a basic the galley and ac unit in the front.. so alot of weight concentrated at the very back and front that could change by quite a bit if I pack lighter or leave the ac unit behind.
Last edited by DrewsBrews on Tue Apr 06, 2021 9:19 am, edited 4 times in total.
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Re: Axle placement

Postby working on it » Tue Apr 06, 2021 8:43 am

bobhenry wrote:THERE MIGHT BE A BIT OF CONFUSION ABOUT THIS THREAD. THE 60/40 OR 65/35 RULE IS WITH THE BODY ONLY. Tongue length has no bearing on this rule.


* Rules aren't set in stone...they're just starting points to aim for. In this case, concerning axle placement (and the corresponding effect it has on the complementary "rule" of tongue weight), there are other views on what works best, and ways to accomplish the desired result.

* When building my 4x8, I found that I had modified my frame as to miss the 60f/40r ratio, and that my tongue length would be too short to compensate...thus adding weight forward was my solution. Meanwhile, I took heart in a quote from a respected teardrop builder, when my trailer was not perfectly proportioned, per the "rules":
tongue weight, balance, according to a respected teardrop guru.jpg
tongue weight, balance, according to a respected teardrop guru.jpg (86.01 KiB) Viewed 1011 times


* Other thoughts: from "Trip Savvy"
For the more experienced RVer, tongue weight is a lever. The trailer’s axle is the fulcrum, and that’s where the lever pivots when being towed. This allows for a trailer to turn and adjust to road conditions, speed, and the wind without snapping back and forth all over the place. When your tongue weight is level, you’ll avoid most sway. If tongue weight is light, the weight shifts behind your axle; if tongue weight is heavy, it shifts ahead of your axle. This affects how your RV or trailer sways, stops and moves on the road.


* If you have a trailer with a normal weight distribution above a normally balanced frame (say 60f/40r), then tongue length doesn't much figure in; but, if the trailer has skewed weight towards the rear, lighter in front, especially if the axle is placed too far forwards, then a longer tongue (or increased weight placed forward on the tongue), serves as a correcting factor, helping to achieve an apparent/effective balance of the complete assembly. Less forward weight is needed if the tongue is long enough, the weight inside is moved forward, or the axle moved further back; balance is achieved in any case (moreso on a single-axle trailer).
2013 HHRv "squareback/squaredrop", rugged, 4x8 TTT, 2225 lbs
  • *3500 lb Dexter EZ-Lube braked axle, 3000 lb.springs, active-progressive bumpstop suspension
  • *27 x 8.5-14LT AT tires (x 3) *Weight Distribution system for single-beam tongue
  • *100% LED's & GFCI outlets, 3x fans, AM/FM/CD/Aux. *A/C & heat, Optima AGM, inverter & charger(s)
  • *extended-run, on-board, 2500w generator *Coleman dual-fuel stove & lantern, Ikea grill, vintage skillet
  • *zinc/stainless front & side racks *98"L x 6" diameter rod & reel carrier tube on roof
173193172890148599
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Re: Axle placement

Postby John61CT » Wed Apr 07, 2021 6:10 pm

Note that UK / Euro standards are completely different from Aus/NZ ones

and of course all those jurisdictions are stricter than the states, coppers actively enforce them.

The US market assumes heavier TVs and (normal) higher highway speeds

not requiring weight-distributing aka "load leveling" hitches.

and our "guidelines" are basically left to "the market" for consumers, as in insurance companies can get out of covering liability leaving you bankrupt

by showing it was built unsafe, especially home made units.
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