11screw50

I'll try to take a look at it this weekend. Been stupid busy at work this week and not much time after work due to kid's practices and whatnot.

Montol

ColbyL, on that spreadsheet next to all of the predicted values, I see you've input under 'Observed (Not including driver)' a FAW = 3250 and RAW = 2950, which only equals 6200#

For the predicted, the total weight should be GVW Observed @ CAT (5675#) + Loaded Weight (1255#) - WDH load shifted to TT weight (155#) = 6775#

That would mean that either something is way off in my calculations, or that I'm interpreting your entries in E54 and E55 incorrectly

ColbyL

That's what I was getting at earlier.
Unhitched. my axles are 3300+2375=5675 (That's with me)
When hitched, they're 2950+3250= 6200 (That's without me)
I'll add me- my numbers should change to 3100+3275= 6375

The spreadsheet says I should be at 3085+3690=6775

difference of 400

sorry about confusion regarding my weight, and it's probably adding some to my own confusion. I actually took all my initial weighings without me. I've just been adding 25 to front and 150 to rear- probably not right, but close enough

Montol

Alright, for clarity's sake, I tried to revise all of the inputs and outputs at various stages, instead of having them dependent on Yes/No's etc.

This will also help determine predicted / observed values when any of us hook up and head out to the CAT scales...see if we can't hammer out a version that actually works...

ColbyL

I think that the value for cell B65 should be:
B61+(B61*((B5+b61)/B4))-B70

You are calculating all the weight added to the rear axle, but not allowing for the weight removed from the rear axle when hitched. This is 404 lbs, which is very close to the discrepancy I am seeing.

ColbyL

I would also suggest doing two separate spreadsheets- one for bumper hitch and one for WD hitch, just to eliminate unneccesary data/confusion. I do like the addition showing amount under/over limit, and removal of overall trailer length input. Possibly, TV overall length is also not necessary.

Another feature might be to add trailer weight as weighed unhitched, to determine CVW vs CVWR.

I also wonder about tandem axle trailers- where is the actual pivot point? I think it would be skewed toward the front trailer axle. Maybe when we get this refined...

Thanks again for this!

Montol

Just to massively conflate @11screw50's original calcs and all of the subsequent thoughts @ColbyL added, I found a pretty useful spreadsheet another user, @BossHauss, had put together for calculating exact curb weight per axle weights which used a few handy Ford resources.

I took that same sheet and did the same weight distribution through the trailer vehicle, then added the whole thing together for the hitch safety check and weight distribution comparison between a standard hitch and weight distribution hitch system.

Chances are it's somewhat wrong, so the more eyes-on, the better.

And hey, if it does actually work, that'd save us all a few trips out to the CAT scale, or at least give people a good idea if they should go because they might be treading the line!

Here it is, in all its terrible glory: Truck and Trailer Weight Distribution Calculator

ColbyL

I don't think it is transferring any weight to the tt axle. If you enter zero for all passengers and cargo, the weight of the tv increases by tongue weight, hitch weight, and bars weight.

Montol

That's right - none of the weight of the hitch or bars would be borne by the TT axle (or at least nearly none of it, just the hooks/clamps for the bar tension). Technically all of that weight of the hitch & bars hangs off the receiver and transfers through the TV rear axle alone, right?

ColbyL

Right, but I was referring to tongue weight transfer