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Weight and balance & hitches


phoenix2013

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I am having conversations with a customer who purchased one of Gregg Shields' truck and is pulling large New Horizon toyhauler (longer than Jack's) which garages on and off 2,200 pounds of bikes. Gregg delivered the truck with an ET Sr. and upon seeing the pair suggested that he call me for a "consultation".

The customer is currently in the "sunshine state" and we are having discussions. I thought this would be a good object lesson to share with this forum about the importance of weight and balance considerations and that not all hitches in the market are created "equal".

The owner did weigh the original rig with the bike on board and the numbers he gave me were: 5th with bikes, but not yet fully loaded 27,600 pounds, pin weight 6,220 pounds.

These numbers told me that the pin weight was within the capacity of a "regular" ET Sr., but it would be prudent to replace the regular Binkley head with a Super Binkley to handle the overall GVWR of the 5th.

However I was curious to see what effect the removal of the bikes would have on the pin weight, I suspected that some portion of the 2,200 pounds would transfer to the pin and I don't like to see much more over 7,000 pounds of pin weight on the Seniors, max capacity being 10,000 pounds.

The customer emailed me that he was moving the fifth without the bikes (but this time FULLY LOADED FOR FULLTIMING) and he could weigh it.

 

Doug%20Shepherd%201_zpsp7l1azqd.jpg

 

Something was off, the drive axle seemed a bit light? So I asked him if he could run the empty truck to the scales and get me those numbers.

 

Doug%20Shepherd%202_zps5ewnitea.jpg

 

HOLY SMOKE!!! Are you running just rails? Yes he is, there is no bed on it just the hitch.

 

So what have we learned here?

 

47,900 lb (the whole rig weight) - 19,960 lb (the truck weight) tells us that the fifth (without the bikes) weighs 27,940 pounds

Add the bikes 27,940 lb + 2,200 = 30,140 lb The weight of the fully loaded toy hauler.

Subtract from that the initial weight 30,140 lb - 27,600 lb = 2,540 lb That's the weight of the "worldly possessions" added to the fifth (other than the bikes)

Subtract loaded truck axle 17,100 lb - 7,800 lb (unloaded truck axle) = 9,300 lb (HOLY SMOKE!!!). That's some pin weight!

 

That's at the upper limit of the Super Sr. ET hitch (13,500 lb).

 

Now I am curious to see how much that pin weigh would go down by loading the bikes on board.

 

Needles to say, we will be upgrading the current ET Sr. to Super Sr. in a week or so.

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Thanks for sharing that education, Henry. You DA Man! Good thing Gregg encouraged him to call you for that consultation. Otherwise, there might have been a failure along some road and hopefully no casualties.

Another example of why this forum and its participants are SO valuable. Knowledge is power and power propels....

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Henry, I confused myself over my actual pin weight for a while. I weighed my rig hooked up and then reweighed disconnected. My pin weight was well above what I thought it should be. I wore out 2 pencils, 3 erasers and scratched a bald spot on my head before I discovered that hooking up the camper added not only its pin weight but almost 1600 pounds that was transferred from the steer axle to the drive axle due to my hitch placement being considerably behind the axles. It was simple math but calculating the way I first did, I really confused myself. Figures don't lie, but the way I calculated them was deceptive....to me, anyway. In the case of the rig in your post, 1440 lbs is transfered from the steer to the drive axle when the trailer is hooked up [according to his weight tickets]. No doubt, the Super Senior will be a good upgrade for his rig. Charlie

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Marcel, I've been a technologist and product designer all my life. Also I had the good fortune to design products in vastly different areas of technology. Some of the list: In military companies, missiles, airborne jamming equipment, combat information centers, airborne display equipment and more. In medical companies, infusion equipment, patient-doctor remote diagnosis and communication equipment, In commercial sector, inventory reporting equipment, self guiding warehouse delivery machinery and control systems, supermarket freezers power optimizations equipment, piano tuning equipment, boat engines sensors and computer integration equipment and many others. Actually, designing ET hitch was one of the less "challenging" efforts.

Why do I list these? I have seen magnificent products, high quality products, designed by folks with substantial intellectual prowess in companies that did not practice cutting corners, or tolerate shoddy effort.

Over the years I have been very critical of the RV Industry for producing shoddy product and cutting corners, to optimize profit, buyer be damned.

 

The reason I posted this thread is because this is a more and more common situation. This is not the first, I've already dealt with rigs over 30K (one over 34K). Have not seen yet one hitch designer, or hitch company seriously dealing with this trend or admitting that a Binkley head on such heavy rigs within year or two will turn to junk. This is not to smear Binkley, it's a great head, but it was not designed (35 years ago) to deal with those weights, regardless what the sticker on it says.

 

You think this is the "end of the trend"? I've been "commissioned" to look into designing an "Ultra ET" for a rig that should be finished by the end of April, an RV not a horse trailer. 57 foot long, 40K + GVWR, 13K pin weight.

No, they are not planning to pull it with a pickup.

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Henry, I confused myself over my actual pin weight for a while. I weighed my rig hooked up and then reweighed disconnected. My pin weight was well above what I thought it should be. I wore out 2 pencils, 3 erasers and scratched a bald spot on my head before I discovered that hooking up the camper added not only its pin weight but almost 1600 pounds that was transferred from the steer axle to the drive axle due to my hitch placement being considerably behind the axles. It was simple math but calculating the way I first did, I really confused myself. Figures don't lie, but the way I calculated them was deceptive....to me, anyway. In the case of the rig in your post, 1440 lbs is transfered from the steer to the drive axle when the trailer is hooked up [according to his weight tickets]. No doubt, the Super Senior will be a good upgrade for his rig. Charlie

 

Charlie, you are absolutely right, 1,440 lbs was "taken away" the front axle by moving the hitch back away from the rear axle. But that is just the teeter totter effect, it doesn't change the pin weight. If the hitch was right over the rear axle the pin weight would be the same but the front axle would return to it's original weight.

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I am having conversations with a customer who purchased one of Gregg Shields' truck and is pulling large New Horizon toyhauler (longer than Jack's) which garages on and off 2,200 pounds of bikes. Gregg delivered the truck with an ET Sr. and upon seeing the pair suggested that he call me for a "consultation".

The customer is currently in the "sunshine state" and we are having discussions. I thought this would be a good object lesson to share with this forum about the importance of weight and balance considerations and that not all hitches in the market are created "equal".

The owner did weigh the original rig with the bike on board and the numbers he gave me were: 5th with bikes, but not yet fully loaded 27,600 pounds, pin weight 6,220 pounds.

These numbers told me that the pin weight was within the capacity of a "regular" ET Sr., but it would be prudent to replace the regular Binkley head with a Super Binkley to handle the overall GVWR of the 5th.

However I was curious to see what effect the removal of the bikes would have on the pin weight, I suspected that some portion of the 2,200 pounds would transfer to the pin and I don't like to see much more over 7,000 pounds of pin weight on the Seniors, max capacity being 10,000 pounds.

The customer emailed me that he was moving the fifth without the bikes (but this time FULLY LOADED FOR FULLTIMING) and he could weigh it.

 

Doug%20Shepherd%201_zpsp7l1azqd.jpg

 

Something was off, the drive axle seemed a bit light? So I asked him if he could run the empty truck to the scales and get me those numbers.

 

Doug%20Shepherd%202_zps5ewnitea.jpg

 

HOLY SMOKE!!! Are you running just rails? Yes he is, there is no bed on it just the hitch.

 

So what have we learned here?

 

47,900 lb (the whole rig weight) - 19,960 lb (the truck weight) tells us that the fifth (without the bikes) weighs 27,940 pounds

Add the bikes 27,940 lb + 2,200 = 30,140 lb The weight of the fully loaded toy hauler.

Subtract from that the initial weight 30,140 lb - 27,600 lb = 2,540 lb That's the weight of the "worldly possessions" added to the fifth (other than the bikes)

Subtract loaded truck axle 17,100 lb - 7,800 lb (unloaded truck axle) = 9,300 lb (HOLY SMOKE!!!). That's some pin weight!

 

That's at the upper limit of the Super Sr. ET hitch (13,500 lb).

 

Now I am curious to see how much that pin weigh would go down by loading the bikes on board.

 

Needles to say, we will be upgrading the current ET Sr. to Super Sr. in a week or so.

Henry,

 

As you might recall .....some time ago I got on my soapbox and preached a few sermons about RV weight and balance.

 

I needed to get a handle on our weight and balance of our rather strange RV that consists of a very plain-jane bumper hitch 30 ft toy hauler with a 1,050 pound Dolly-the-paint-horse loaded (Center of longitudinal Gravity) in the far aft EIGHTEEN inches of the toy hauler garage....

 

Now to just to create a bit of challenge I SELF-imposed a REDUCED Total weight of the toy hauler to LESS than 80% of trailer listed Gross weight AND NO tire position weight greater than 80% rated tire capacity.

 

While almost everyone here on the forum is trying to figure ways to "Carry more and more on the trailer and hitch" I was "CALCULATING" ways to get way under the Trailer LISTED Gross Weight.

 

In my previous "life" I was at times in

...."situations"... that involved overloaded aircraft...a few times GROSSLY overloaded, BUT even though I was GROSSLY overloaded I Still took the time and EFFORT to mitigate the overweight condition in such a manner that BALANCE did NOT became.....UNCONTROLABLE.

 

So....in my previous"Life" I used up All of my Nine-lives...as well as someone's lives as well and now that I have reached the goal of....Geezerhood .... I have turned a bit "chicken"....

 

Some days I Calculate the Dollytrolley weight and balance on my LIVE DATA CALCULATING spreadsheet and wonder if I am carrying this "geezer-chicken " thing a bit far....

 

While my weight and balance spreadsheet is fairly"Utility -grade" in appearance it has proven that simple math still works AND just to prove the point I weigh the Dollytrolley every time I can sneak across a set of scales and sire enough...math still works.

 

So Henry, if yo desire to find out how much the heavy-hauler rig combo pin, axles , etc ... weights are with and without the motorcycle($) aboard .....just email me at : mmcdan3189@aol.com and by return email I will send you my live-data spreadsheet via return email.....

 

Now the DISCLAIMER: The Dollytrolley weight & balance live-data-spreadsheet is a computer based calculation program and as such so it is ONLY as accurate as the base-data input into the spreadsheet cells.....so for example with Dolly-the-paint-horse it's the classic example ....fresh hay into Dolly when we load her in the horse module and the course of the day some of the ....ah....hmmmmm..."used-hay", may be.....offloaded.....Anyhow you get the idea....just adjust your spreadsheet cell values and the spreadsheet auto-calculates the All of the axle and hitch loads.... simple math.

 

Drive on.....(Dolly eats a lot of hay)

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But that is just the teeter totter effect, it doesn't change the pin weight. If the hitch was right over the rear axle the pin weight would be the same but the front axle would return to it's original weight.

??? You seem to be neglecting multiplying by the moment arm as Sclord2002 pointed out. Not knowing that distance, how could you determine the pin weight as opposed to the rear axle weight?

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From my perspective, it seems like the math is this:

 

Truck + Trailer scales in at: 47,900 lbs

 

Truck alone scales in at: 19,960 lbs

 

Therefor, the trailer must weigh:

 

(truck + trailer) - (truck)

(47,900) - (19,960) = 27,940 lbs = The Trailer Weight

 

And you know how much of the trailer weight is on the trailer axles from the scale ticket: 20,080 lbs

 

That means that the pin weight must be the trailer weight minus the trailer axle weight:

 

(Trailer weight) - (trailer axle weight)

(27,940) - (20,080) = 7,860 lbs = The Trailer Pin Weight

 

Since the truck's steer axle weight has gone down from 12,160 lbs with no trailer to 10,720 lbs with the trailer (a difference of 1,440 lbs), that means that the pin weight is being applied behind the drive axles and is using the drive axles as a fulcrum. This is causing some of the steer axle weight to be pulled off of the steers and shifted to the drive axles. So what you really have on the drive axles is their original weight (7,800 as measured on the scale ticket for the truck with no trailer) plus the trailer's pin weight (7,860) plus the weight off of the steer axles (1,440):

 

(Drive Axles with no trailer as reported on scale ticket) + (Trailer Pin Weight calculated above) + (Weight transferred from front axle to drive axles)

(7,800) + (7,860) + (1,440) = 17,100 lbs = Calculated Drive Axle Weight

 

Which exactly equals the scale's measurement of the drive axles, validating that our calculations are accurate, proving that the pin weight is 7,860 lbs.

 

So, your actual pin weight is 7,860 lbs without the motorcycles. The pin weight will certainly change with the motorcycles loaded. But if they are placed behind the trailer axles, the pin weight will go down since the motorcycles will use the trailer axles as a fulcrum and transfer weight from the pin to the axles.

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Folks I typed up a offer to SOLVE the ENTIRE mysterious"what IF we load the motorcycles" in the RV...

But my offer totally evaporated into the black wholeee of the internet... (likely I exceeded the ...dot quota)

 

Anyhow someone call my cell at (520) 891-3695 and give me some baseline data and I will answer ALL of the weight and balance MYSTERY(s) in a few clicks of the mouse on the spreadsheet......

 

Typing on a cell phone ....shucks on....

 

Drive on....(poof.... post....gone)

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Marcel, I've been a technologist and product designer all my life. Also I had the good fortune to design products in vastly different areas of technology. Some of the list: In military companies, missiles, airborne jamming equipment, combat information centers, airborne display equipment and more. In medical companies, infusion equipment, patient-doctor remote diagnosis and communication equipment, In commercial sector, inventory reporting equipment, self guiding warehouse delivery machinery and control systems, supermarket freezers power optimizations equipment, piano tuning equipment, boat engines sensors and computer integration equipment and many others. Actually, designing ET hitch was one of the less "challenging" efforts.

Why do I list these? I have seen magnificent products, high quality products, designed by folks with substantial intellectual prowess in companies that did not practice cutting corners, or tolerate shoddy effort.

Over the years I have been very critical of the RV Industry for producing shoddy product and cutting corners, to optimize profit, buyer be damned.

 

The reason I posted this thread is because this is a more and more common situation. This is not the first, I've already dealt with rigs over 30K (one over 34K). Tell me one hitch designer that seriously dealing with this trend or admitting that a Binkley head on those within year or two will turn to junk with those weights. This is not to smear Binkley, it's a great head, but it was not designed (35 years ago) to deal with those weights, regardless what the sticker on it says.

 

You think this is the "end of the trend"? I've been "commissioned" to look into designing an "Ultra ET" for a rig that should be finished by the end of April, an RV not a horse trailer. 57 foot long, 40K + GVWR, 13K pin weight.

No, they are not planning to pull it with a pickup.

Precisely why I respect and appreciate you and your work. Also why I offered my services. I, more often, overbuild what I am commisioned to fabricate. People like you continue my education and knowledge.

Thank you again.

 

Marcel

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Hmm...SHifted summary seems reasonable, but...we do have to think about levers/etc. Is Henry getting too much SUN?? Is SHifted being to simple in the math? NOt sure I want to think that hard... Let Dolly Trolley's spreadsheet do the thinking. (and to think I once got a degree in Physics...)

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Shifted is absolutely correct, the off load off the front axle is a "phantom number" that has nothing to do with the actual pin weight. It is a force moment generated by the fact that the pin weight is not acting directly onto the rear axle but is pressing down several feet beyond the axle, which is the fulcrum.. Should the hitch be moved forward directly over rear axle the 1,440 pounds on the rear axle would disappear and would re-appear on the front axle.

Force moments on balanced beams are ratios of distance and weights. The ratio of 12,160 to 1,440 could be used to calculate how far the hitch head is behind the rear axle, if one knows what the wheelbase of the truck is.

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Shifted is absolutely correct, the off load off the front axle is a "phantom number" that has nothing to do with the actual pin weight. It is a force moment generated by the fact that the pin weight is not acting directly onto the rear axle but is pressing down several feet beyond the axle, which is the fulcrum.. Should the hitch be moved forward directly over rear axle the 1,440 pounds on the rear axle would disappear and would re-appear on the front axle.

Force moments on balanced beams are ratios of distance and weights. The ratio of 12,160 to 1,440 could be used to calculate how far the hitch head is behind the rear axle, if one knows what the wheelbase of the truck is.

 

Makes you understand why a DROM, a SmartCar/Bed and maybe an APU may make you want to think about a 13.5 or 14K front axle as well.

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Dollytrolly was it the post early this morning? If so it is about 3 posts back.

 

Did you ever get a chance to send me your spreadsheet? I do not recall getting it and hoping it did not go into the spam container

Star I sent the spreadsheet some time back however we have been out in the outback for considerable time with only one bar signal on our cell data plan most days so some files just die from drop put.

 

I will resend the spreadsheet next time I get into civilization or get the cell configured as a hot spot and try to resend on our data plan with my Linux notebook.

 

My post from this morning was too long from my phone and my fat-fingers just ticked off the phone gods and zip-gone....way too bad it was a fabulous post and it was likely to make America great again....

 

Oh well I will likely cobble up a new post from my notebook fairly soon and fix the motorcycle loaded and unloaded MYSTERY....

 

Drive on... ..(phone internet is. .phoney)

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Makes you understand why a DROM, a SmartCar/Bed and maybe an APU may make you want to think about a 13.5 or 14K front axle as well.

 

The second truck brought to me for conversion (after mine) was singled long.

 

2902466360096176628QkFYBn_fs_zpsg79zvnm2

 

The drom was performing several duties. It had an overhead hoist to garage two bikes. It was also serious storage space, including a food freezer. The owner is a serious commercial Chef (he was in charge of food in the New Orleans Superdome after Katrina) and he travels all over the country representing food companies.

 

2052854280096176628qbaVse_fs_zpslsg4ck03

 

2678147860096176628apTRtE_fs_zpsweudnfxc

 

Driving the truck with rails only I noticed one significant difference. The truck would brake much better than mine which was singled short and the rear end would break on a slightest excuse (until I added some serious weight over the rear axle). However, adding two bikes to what was already in the drom would overload the front axle. This situation would remedy itself if the trailer was hooked up to the hitch mounted behind the rear axle.

 

2036257080096176628kieOAF_fs_zpsid3xkbyy

 

The hitch head was mounted about 3 feet behind the rear axle but it was enough to offload the front axle sufficiently.

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I am having conversations with a customer who purchased one of Gregg Shields' truck and is pulling large New Horizon toyhauler (longer than Jack's) which garages on and off 2,200 pounds of bikes. Gregg delivered the truck with an ET Sr. and upon seeing the pair suggested that he call me for a "consultation".

The customer is currently in the "sunshine state" and we are having discussions. I thought this would be a good object lesson to share with this forum about the importance of weight and balance considerations and that not all hitches in the market are created "equal".

The owner did weigh the original rig with the bike on board and the numbers he gave me were: 5th with bikes, but not yet fully loaded 27,600 pounds, pin weight 6,220 pounds.

These numbers told me that the pin weight was within the capacity of a "regular" ET Sr., but it would be prudent to replace the regular Binkley head with a Super Binkley to handle the overall GVWR of the 5th.

However I was curious to see what effect the removal of the bikes would have on the pin weight, I suspected that some portion of the 2,200 pounds would transfer to the pin and I don't like to see much more over 7,000 pounds of pin weight on the Seniors, max capacity being 10,000 pounds.

The customer emailed me that he was moving the fifth without the bikes (but this time FULLY LOADED FOR FULLTIMING) and he could weigh it.

 

Doug%20Shepherd%201_zpsp7l1azqd.jpg

 

Something was off, the drive axle seemed a bit light? So I asked him if he could run the empty truck to the scales and get me those numbers.

 

Doug%20Shepherd%202_zps5ewnitea.jpg

 

HOLY SMOKE!!! Are you running just rails? Yes he is, there is no bed on it just the hitch.

 

So what have we learned here?

 

47,900 lb (the whole rig weight) - 19,960 lb (the truck weight) tells us that the fifth (without the bikes) weighs 27,940 pounds

Add the bikes 27,940 lb + 2,200 = 30,140 lb The weight of the fully loaded toy hauler.

Subtract from that the initial weight 30,140 lb - 27,600 lb = 2,540 lb That's the weight of the "worldly possessions" added to the fifth (other than the bikes)

Subtract loaded truck axle 17,100 lb - 7,800 lb (unloaded truck axle) = 9,300 lb (HOLY SMOKE!!!). That's some pin weight!

 

That's at the upper limit of the Super Sr. ET hitch (13,500 lb).

 

Now I am curious to see how much that pin weigh would go down by loading the bikes on board.

 

Needles to say, we will be upgrading the current ET Sr. to Super Sr. in a week or so.

Answer: 9,300 pound pin weight drops 892 pounds when motorcycles (2,200 lbs) are loaded at 520 inches aft of hitch with a 370 inch avg wheelbase trailer...new pin wt= 8,408 lbs.

 

Disclaimer: since I had almost no clues what the actual dimensions of the truck and trailer really are .....I just started moving things around in the spreadsheet until the few numbers that I was able to gleam form the various posts started to give me some clues what a theoretical truck and trailer might be configured like......

 

So how far off is my guess off? ?

 

If I had real numbers it would be silly easy to answer the real question(s)...

 

Drive on.....(where are the ######'s)

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From my perspective, it seems like the math is this:

 

Truck + Trailer scales in at: 47,900 lbs

 

Truck alone scales in at: 19,960 lbs

 

Therefor, the trailer must weigh:

 

(truck + trailer) - (truck)

(47,900) - (19,960) = 27,940 lbs = The Trailer Weight

 

And you know how much of the trailer weight is on the trailer axles from the scale ticket: 20,080 lbs

 

That means that the pin weight must be the trailer weight minus the trailer axle weight:

 

(Trailer weight) - (trailer axle weight)

(27,940) - (20,080) = 7,860 lbs = The Trailer Pin Weight

 

Since the truck's steer axle weight has gone down from 12,160 lbs with no trailer to 10,720 lbs with the trailer (a difference of 1,440 lbs), that means that the pin weight is being applied behind the drive axles and is using the drive axles as a fulcrum. This is causing some of the steer axle weight to be pulled off of the steers and shifted to the drive axles. So what you really have on the drive axles is their original weight (7,800 as measured on the scale ticket for the truck with no trailer) plus the trailer's pin weight (7,860) plus the weight off of the steer axles (1,440):

 

(Drive Axles with no trailer as reported on scale ticket) + (Trailer Pin Weight calculated above) + (Weight transferred from front axle to drive axles)

(7,800) + (7,860) + (1,440) = 17,100 lbs = Calculated Drive Axle Weight

 

Which exactly equals the scale's measurement of the drive axles, validating that our calculations are accurate, proving that the pin weight is 7,860 lbs.

 

So, your actual pin weight is 7,860 lbs without the motorcycles. The pin weight will certainly change with the motorcycles loaded. But if they are placed behind the trailer axles, the pin weight will go down since the motorcycles will use the trailer axles as a fulcrum and transfer weight from the pin to the axles.

So Answer: if you load the motorcycles at 520 inches aft of the hitch pin on a 370 inch avg trailer wheel base hitched to a 283 inch wheelbase truck with a hitch at 335 inches aft of the steer axle your hitch pin load of 7,860 lbs drops to 6,968 lbs when you load 2,200 lbs of motorcycles at 520 inches.....then spreadsheet numbers match your numbers....AND scale numbers.

 

Disclaimer: I had no truck or trailer layouts to reference so I just input axles and hitch locations to arrive at theoretical truck and trailer layouts.... CIA gig....

 

Drive on ....(spook wt & bal....)

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Answer: 9,300 pound pin weight drops 892 pounds when motorcycles (2,200 lbs) are loaded at 520 inches aft of hitch with a 370 inch avg wheelbase trailer...new pin wt= 8,408 lbs.

 

Disclaimer: since I had almost no clues what the actual dimensions of the truck and trailer really are .....I just started moving things around in the spreadsheet until the few numbers that I was able to gleam form the various posts started to give me some clues what a theoretical truck and trailer might be configured like......

 

So how far off is my guess off? ?

 

If I had real numbers it would be silly easy to answer the real question(s)...

 

Drive on.....(where are the ######'s)

So....IF you look at BOTH of my last TWO posts AND both of my TWO "ANSWERS"....do you notice anything? ?

 

Hmmmmm.. . Well folks as the old saw says..."lier's can number, AND numbers can lie...Sorta or sorta not.

 

Clue IF we look at the End-of-post "Answer" pin weight with motorcycles loaded we have a choice of my calculated weights of 8,408 lbs or 6,978 lbs....so which number is correct.....well in some ways both numbers are.... "relevant"....how can both numbers be correct? ?

 

HINT: simple math....

 

Ok I never intended for my wt & bal spreadsheet to be used to "reverse-compute-truck-trailer-axle-hitch-layouts"....but what the heck what do I know.... spreadsheet does the work for me.

 

Anyhow how can both"ANSWERS" be sorta correct.... sorta?

 

PRIZE: correct (sorta) answer(s) gets a .. almost complete version of my spreadsheet E-mailed....

 

Drive on....(answers...sorta)

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So....IF you look at BOTH of my last TWO posts AND both of my TWO "ANSWERS"....do you notice anything? ?

 

Hmmmmm.. . Well folks as the old saw says..."lier's can number, AND numbers can lie...Sorta or sorta not.

 

Clue IF we look at the End-of-post "Answer" pin weight with motorcycles loaded we have a choice of my calculated weights of 8,408 lbs or 6,978 lbs....so which number is correct.....well in some ways both numbers are.... "relevant"....how can both numbers be correct? ?

 

HINT: simple math....

 

Ok I never intended for my wt & bal spreadsheet to be used to "reverse-compute-truck-trailer-axle-hitch-layouts"....but what the heck what do I know.... spreadsheet does the work for me.

 

Anyhow how can both"ANSWERS" be sorta correct.... sorta?

 

PRIZE: correct (sorta) answer(s) gets a .. almost complete version of my spreadsheet E-mailed....

 

Drive on....(answers...sorta)

 

 

You're starting to make a SS sound interesting...

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So....IF you look at BOTH of my last TWO posts AND both of my TWO "ANSWERS"....do you notice anything? ?

 

 

Hmmmmm.. . Well folks as the old saw says..."lier's can number, AND numbers can lie...Sorta or sorta not.

 

Clue IF we look at the End-of-post "Answer" pin weight with motorcycles loaded we have a choice of my calculated weights of 8,408 lbs or 6,978 lbs....so which number is correct.....well in some ways both numbers are.... "relevant"....how can both numbers be correct? ?

 

HINT: simple math....

 

Ok I never intended for my wt & bal spreadsheet to be used to "reverse-compute-truck-trailer-axle-hitch-layouts"....but what the heck what do I know.... spreadsheet does the work for me.

 

Anyhow how can both"ANSWERS" be sorta correct.... sorta?

 

PRIZE: correct (sorta) answer(s) gets a .. almost complete version of my spreadsheet E-mailed....

 

Drive on....(answers...sorta)

Shucks....I guess I should've threw a two liter jug of Dr Pepper into the prize for the answer to the "MYSTERY" of how both weights are .... sorta correct...

 

Drive on....(dang those darn pounds)

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Dolly, it seems that you are [and are not] taking the weight shift from the front axle. The difference in your 2 numbers is 1430 pounds and the weight shift from the steer axle to the drive axle is 1440 lbs with no bikes loaded. Loading the bikes shifts some weight from the drive axle back to the front axle.......at least that is the way I sorta figured weight and balance on our old C-47's many years ago. Pigs, out of their cages, and Vietmamese farmers trying to get them re-caged made a significant in-flight shift of CG and caused the pilot to see-saw just a bit as the pin weight changed on the fly, so to speak. Charlie

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