Tongue weight and Total weight

[Derson59]

This is my initial calculations for my TD. Does this look about right. I have a avenger that only tows 1000lbs max.
[img]
Basic measurements in
Body length from rear - A 96
Hitch center from rear - B 140
Wheel center from rear - C 43

Extra weight measurements in
Extra weight 1 from rear - D1 40
Extra weight 2 from rear - D2 108
Extra weight 3 from rear - D3 48

Basic Weights % of Basic lb.
Basic trailer weight 100% 253
Weight of tongue 5.0% 12.65
Weight of axle/suspension 12.0% 30.36
Body weight (total - tongue - axle) 83.0% 209.99

Extra Weights (not included in Basic) lb.
Extra weight 1 50
Extra weight 2 25
Extra weight 3 100

Results
Total trailer weight, 428 lb.
LCG from rear - X, 52.3 in. % of Total
Weight on axle, 387 lb. 90.4%
Weight on each wheel, 194 lb.
Weight on hitch, 41 lb. 9.6% [/img]

[bobhenry]

If I understand correctly you have a 96 inch body with the center of the axle located 43 inches from the rear and 53 inches from the front of the body The 44" tongue length is ignored in this calculation ( but that 44" is a generous length )

What you currently have is a balance ratio of 45% rear and 55% front ( 43/96= .4479 53 / 96 =55.21) at the body

40 / 60 is alright and 35 / 65 is better also 9+ % tongue weight is not quite enough ( 41 / 428 = .0958)

15% is almost the minimum. With your current set up You may experience sway at highway speed with the load so near centered and difficulty backing due to wheel placement so far forward. Coupler rattle will also occur due to the extremely light tongue weight. Can I suggest 29" form the rear to the axle centerline. This should all but eliminate all three problems.

BUT WHAT THE HELL DO I KNOW !

Perhaps others will chime in with their thoughts !

[Derson59]

thank you. I have seen others just not move the axel back at all. And used it where it normally is. I will have to measure to see what kind of tongue weight I do get.

[KCStudly]

From what I have seen, the people who do not move the axle back, in general, do not do so because they aren't handy working with steel and feel it is too difficult due to their lack of experience; and they often times either end up doing it after the fact (with tribulation) or wish that they had.

I have read a lot on these forums since I first got here, and that is what I have gathered.

BTW, ole Bob Henry there, he probably has as much practical experience fiddling with these small trailers as anyone, so when he says 'WTH do I know', that there is sarcasm.

On the other hand, Angib is just as likely to chime in and counter that, if you are in Europe, towing a relatively larger trailer with a relatively smaller car on little old roads at slower speeds, then 5 to 10/ct tongue weight might actually work better; but if you are bombing across the states on a super slab with a larger size TV (even our modern day standard "midsize" vehicles can be considered "large" by comparison) then more tongue weight (to a point) doesn't hurt.

I have a tilt bed utility trailer and the axle on that is actually more than 50/ct of the bed forward. It helps make it easier to tilt the bed up for loading and softens that loading angle when tilted. There is a little tongue weight on the hitch when empty due to the tongue, but it rattles the hitch a lot when empty and tows nasty if you are not careful to bias all loads to the front. And despite being a 5x8, it is not easy to back up. If it wasn't for the tilt feature the first thing I would do is move the axle back. Just saying, it's another data point.

[working on it]

Like KC, I respect Bobhenry's experience with trailers over the years. He knows what works, normally. I also knew of KC's reference to European tongue weight, and figured that when my elaboration on Angib's excellent trailer balance spreadsheet (I now have 30 different versions done for my trailer) showed that the 15% balance was unreachable for my trailer, I would at least try to achieve the European standards. With an ace in the hole...I devised a single beam version of my Weight Distributing hitch (I use it on all my trailers), to make the light tongue "act" heavier. At the latest configuration, my trailer has 9.9% tongueweight (160 lbs), and probably doesn't need the WD crutch. But here's a quote from a well-respected builder on this Forum, and how he viewed the "absolutely must have" 15% tongueweight rule that most people here adhere to: “In general terms, the rule of thumb on a typical teardrop is one third (1/3) of the body length from the rear edge of the body is where the axle/spindle centerline should be. So, in genreal terms a typical 4'x8' bodied teardrop should have its axle/spindle centerline 32" from the rear of the body and a 5'x10' teardrop will have it at 40" from the rear of the body. However, amount of cabinetry (and where it is placed) and number of appliances will affect that figure. My 8'ers run at about 31" and 10'ers at about 43", but I don't hold cotton to that 10-15% tongue-weight spec ... I like it in the 5-7% range ... and that's just me”. – Grant Whipp Mon Feb 12, 2007 12:36 pm. Try for a good balance, and modify until you achieve something that works for you. There seems to be no absolute values in trailer-building!

[KCStudly]

So to narrow this down, IMO the single most important thing is to make sure you can put your side doors (plural... you will want two) in a comfortable location and have the fender clear the door trim (you want to "sit" in the doorway and "spin" on your seat by rolling back and drawing your legs in while you turn so that you end up in your natural laying down position. Don't think that you will be happy crawling thru a door that is placed too far forward and then maneuver until you get into position. If the door is too far forward to make room for the fender you will not be comfortable, can hit your head on front cabinets or bunk, and will have to do a whole bunch of scooting. (Again, this is my opinion... I'm older, overweight, and don't like crawling on my knees too much; plus there is the comfort of your sleeping partner to consider.)

The next thing is does the trailer tow and back up well? To me it seems that a longer tongue and/or a rear set axle makes a trailer tow much smoother and back much easier than just getting a certain amount of weight on the tongue. (My 16 ft boat trailer tows and backs really nice with its rear set axle and long tongue; not so much my UT with its too far forward axle, short tongue and shorter overall length.) This is simple physics and geometry. The maker of the entry level lowest cost trailer kits is not going to provide you with anymore steel than necessary to get the job done, so do yourself a favor and look at some of the threads that show how to lengthen the tongue. This will have the same effect as moving the axle rearward.

Lastly, with a mere 1000 lbs limit, you will probably not have much trouble hitching and unhitching, nor maneuvering the trailer tongue manually while doing it, so going a little more on the tongue weight shouldn't really hurt in that regard. (Some guys like to go real light on the tongue just so they can still pick it up by hand. Me, I use a good tongue jack and save my back.)

BTW, welcome to the forum! You are starting off in the right direction by checking in and trying to get the basic stuff sorted out correctly from the beginning. There is a lot of good knowledge and experience here.

.... and yes, it does seem as though you really can't go too far wrong no matter what you do (especially when building small and light), but then it seems that sometimes even just a little far wrong ends up costing aggravation and "redoes" later.

My how I ramble on!

[ctstaas]

Hi there, The general consensous I agree with is the axle should be at 66% of the load. Do not figure the length of the tongue when placing the axle. No closer then 50% of the load. From 50% to 66% is 16% so landing the axle within this 16% is kind of important.
Enjoy, Chris

[Redneck Teepee]

Everyone has very good info on follow ups to the post, no bad info given.

Just to add another twist or point of approach, I have built a few trailers in my days and some of them were specialty applications which has no merit here. An old trailer builder told me years ago (and I listened).... for a standard run of the mill trailer, for towing perfection.... always place the center line of your axle or axles with 60% or 5/8's of the cargo area forward of that point,.... forget the tongue, it does not enter into the equation.... It has worked flawlessly over the years and has never failed me.
Again all good information.

[working on it]

.... always place the center line of your axle or axles with 60% or 5/8's of the cargo area forward of that point,....

Previously, I had an axle mounted too far forward (per forum consensus). I moved as much weight forward as I could, to make up for the rear weight bias, but need added forward structure to make it a permanent fix. I added a large tongue box to hold items previously stored rearward, to shift the effective mass of the trailer forward. The mass forward also shifts the 60%/40% axle centerline point "ideal" forward, as well. As illustrated by this line drawing

red & blue circles based on original non-tonguebox cabin structure; green shows change afterwards

magic 60% axle location.png (30.96 KiB) Viewed 690 times

So, in effect, I moved my axle past the 60% "ideal", without the axle being re-located (which was possible, but not a practical solution, in my case).