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Jaybird180

New Trailer Setup- Weight and Balance

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Jaybird180    30

I just bought a 6x12 trailer. After missing a trackday a couple weeks ago, I'd had enough and got serious about it. Found a great deal. I'm planning some upgrades for the trailer already.

One of the essentials I'd decided upon is the PitBull Trailer Restraint System for our bikes. I'm waiting for my guy to get back to me as I put him on hold until I actually completed the purchase, now I'm itching to get the systems installed.

Being the egghead that I am (and having an aviation background) I know a little about Weight and Balance. A front loaded trailer tends to be more stable, and a rearward Center of Gravity (aft of the axle) is less stable. Considering my tow vehicle has was I consider a limited tow capacity, I decided that I'd like to install the 900lbs of motorcycle on the Axle and use moveable gear (toolboxes, etc) as ballast. Pretty soon I'll take some measurements and see if this works from a space availability perspective.

I recall a few posts with C*G data but I'm hoping to find something authoritative on the matter. Otherwise I'll have to take measurements myself, which I don't mind doing. Anyone?

Does anyone have any cautions for or against my plan? I'd like to install the TRS once (and maybe make an outline for days when it's just a single bike going) and be done with it.

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khp    2

Jaybird,

I trust you've seen this demo of right vs wrong weight distribution on a trailer (it's been widely copied around on sites):

From this, I'd put the bikes as close to the front as possible.

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Jaybird180    30

Thank you for finding that, I'd seen it some time ago and didn't know how to find it again.

Although one could load a trailer front heavy, there are limits to the tongue weight of trailer hitches. If too nose heavy, it could cause excessive tow vehicle squat in the rear, lightening the steering wheels, reducing controllability and also giving problems with headlight aim. In the extreme cases, it could cause structural failure of either vehicle's frame or attachment points. From what I've read, general rule of thumb is 10-15% gross trailer weight should be placed at the tongue.

I got a recommendation to use a single bathroom scale at the front, load the bikes allowing only 90-135lb (10-15%) increase at the tongue jack then use that as the location to install the TRS. I'm not sure of this plan and certainly don't want to use my new-ish glass Bluetooth body analysis bathroom scale.

FWIW- I called PitBull last week and while they assured me that my concerns were valid, they'd never had anyone call to ask that question. Which means that in finest tradition, I'm probably overthinking this. However many people load bikes on as little as 72" length trailers but I have an additional 48" or 50% I can play with; I think there's room to get it wrong and my professional truck-driving father-in-law agrees that it can be done wrong. On point, when driving back from L4 at NJMP, I packed the open trailer in haste and my wife driving said the vehicle didn't feel comfortable. We pulled over and I moved the tool bin from the extreme rear to the extreme front of the trailer and it made a noticeable difference for the remainder of the 3hr trip home.

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khp    2
16 hours ago, Jaybird180 said:

Which means that in finest tradition, I'm probably overthinking this.

Now that wouldn't be the first time we did that :P

I'm not a trailer expert by any chance, so do go by PitBull & you father-in-law recommends. I switched from open trailer (~7', only had bikes on it) to a closed van in '05 which made any concerns pretty moot for me.

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Hotfoot    48

We've towed a variety of different trailers and as you stated above, there is room to get it a little "wrong". As long as you are not extreme in loading the very back or very front unevenly you shouldn't have much trouble, so putting the bike(s) over the axles ought to handle it without having to get it right within a couple of inches.AS an example, think of toyhaulers - they have a huge amount of trailer weight in tanks for fresh water, gray water, holding tank, and large fuel tanks (on board fuel station) and the loads very considerably between empty and full and in between, but the trailer hauls solidly regardless (well, ours have, anyway) of which tanks are full or empty. Those tanks are placed near the axles, of course. Personally the only time I've had trouble was when the vehicle hitch was too high so the trailer was not level (it was high in front which made it want to wag) or if ALL the weight was in the back of the trailer, which I accomplished once by loading a small trailer (14 foot) with a riding mower and nothing else, and putting the mower in the very back. That didn't feel good to tow, but I hadn't been paying attention to how I loaded it since I was only going down the street. I wouldn't do it that way again. :) 

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Jaybird180    30

Nail on the head with loading over the axles. I am a little concerned about the wasted space though and this particular trailer feels heavy at the tongue (It's got wooden walls). In a couple days or so, I'll have the parts received to add brakes, which while not required will add a measure of safety.

I found a station willing to weigh my rig. It's a dump site not far from my house, so that's good. I'll likely go by and weigh empty then calculate, test load the bikes and re-weigh.

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Jaybird180    30

Well, we skipped the empty weight part. The trailer is at the shop getting it's upgrades. I also tried out the TRSs and I admit that it's one thing that I will need to read the instructions for as there is a part that gets installed on one of the bikes. I had to figure out which because they didn't mark them.

We ballparked where to install the mounting plates. The weigh in will tell me if we got it right or how much ballast will be needed.

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