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05-15-2012, 08:55 PM
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#21
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Member
Join Date: May 2012
Location: Oregon
Posts: 31
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Quote:
Originally Posted by mtnguy
Airbags and better tires do not add to a vehicle's GVWR, or RAWR. A properly setup WDH should prevent sagging.
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That's why I said, "right up the max" not over. I know nothing adds to the weight limits set by the manufacturer. Airbags and better tires just help relaize the maximum better, IMO.
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05-15-2012, 09:17 PM
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#22
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Junior Member
Join Date: May 2012
Location: Texas
Posts: 17
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Hard for me to figure out what the MVCW is too. We have removable bucket seats rather than a bench seat in the second row. Could that be part of it? The seats are heavy - but they don't weigh 150 lbs each! Makes me realize we could remove them to lighten our load if needed! I am going to try to get my husband to go weigh the car empty this weekend and will post back if we do so. We can also use the learning experience on where and how to go about weighing.
I like the advice of going for the 4 point hitch - so we can use it if/when we upgrade again. Clearly we have begun the roll down the slippery slope. Wonder where it will end!
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05-15-2012, 09:23 PM
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#23
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Site Team - Lou
Join Date: Oct 2009
Location: South Eastern PA
Posts: 23,269
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Quote:
Originally Posted by NancyTX
Wonder where it will end!
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Hopefully having fun like never before.
__________________
Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
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05-16-2012, 12:01 PM
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#24
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Junior Member
Join Date: May 2012
Location: Texas
Posts: 17
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Well - funny thing. I decided to clean out the garage this morning, partly to cope with the excitement of having decided to order the 2604 (and the long wait before we get it ), and partly because the garage really, really needs it. In doing so I "discovered" the two other captains chairs that go into the Yukon to make a third row of seating. I had completely forgotten about them because they have been out of the vehicle so long. They are heavy, and I am betting they are part of the mystery regarding the difference between payload and that MVCW number on the car door. We will weigh the vehicle with and without them and see what we come up with.
Second funny thing - upon sharing this thread with husband when he got home, he says to me, "If we have to get a new TV it is OK because I have always wanted to have a truck anyway." That certainly makes it easier to go ahead with the 2604. Heck - maybe I should have argued for that Windjammer I also loved!
Anyway - now I have to figure out how to distract myself while waiting for the new TT. The dealer said end of June. Hope it isn't any longer.
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05-16-2012, 01:20 PM
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#25
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Site Team - Lou
Join Date: Oct 2009
Location: South Eastern PA
Posts: 23,269
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[QUOTE=NancyTX;196870In doing so I "discovered" the two other captains chairs that go into the Yukon to make a third row of seating. I had completely forgotten about them because they have been out of the vehicle so long. They are heavy, and I am betting they are part of the mystery regarding the difference between payload and that MVCW number on the car door. We will weigh the vehicle with and without them and see what we come up with.[/QUOTE]
The mystery option weight, maybe...
__________________
Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
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05-16-2012, 02:27 PM
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#26
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Junior Member
Join Date: May 2012
Location: Chicagoland
Posts: 17
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Nancy,
I don't think you'll have a problem with your set up. You're not really getting too close to your limits. We towed our Rockwood 8317SS with a 2008 Suburban 4 speed trans with 4.10 rear gear for the past few years near the limit. We switched to the Denali this year. Power should not be an issue. The 2011 Denali is rated at 7,300 GVWR, 8,100# max tow and 14,000# GCWR. We'll be close to the max on the GVWR and GCWR.
__________________
4Galvs + DN = 5Galvs
2009 Rockwood 8317SS O 2011 GMC Yukon Denali AWD
5Galv's Campsite
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05-16-2012, 04:01 PM
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#27
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Junior Member
Join Date: May 2012
Location: Texas
Posts: 17
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To 5Galvs - I enjoyed your "campsite".
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05-19-2012, 11:57 PM
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#28
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Junior Member
Join Date: May 2012
Location: Texas
Posts: 17
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We weighed the Yukon today
It weighed 5590, with a full tank of gas and no people. The third row seats were removed, but the second row seats were in the car.
Running this through the calculators, it seems that after putting the people, the dog, the 110lb hitch, and 50 lbs of other misc in the car, we are limited to a hitch weight of 830 pounds. Any more than this and we exceed the vehicle GVWR of 7100.
If hitch weight is usually 13% of trailer weight, the trailer loaded needs to be no more than 6385lbs to ensure the tongue weighs no more than 830. While this is doable (we think the dry weight of delivered trailer will be about 5850) we will have to pack carefully. However, if hitch weight is only 12% of trailer weight, we have a lot more wiggle room. Can tongue weight be significantly influence by where things are placed in the trailer? How likely is it that we could get tongue weight down to 12% by loading in the back half of the trailer?
Secondly, a previous poster suggested that the rear axle weight may be the real limiting factor for us. My manual says the tongue weight may add more than 1 1/2 times its weight to the rear axle - for example that an 800 pound tongue could add 1200 pounds to the axle. If so, that will be a real problem for our car. Does the equalizer hitch help with this at all?
Thanks again for any info.
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05-20-2012, 06:10 AM
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#29
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Site Team - Lou
Join Date: Oct 2009
Location: South Eastern PA
Posts: 23,269
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Can tongue weight be significantly influence by where things are placed in the trailer? How likely is it that we could get tongue weight down to 12% by loading in the back half of the trailer?
Yes, loading your camper will be a balancing act every time you go out until you get a feel for where everything goes. You can very likely get the 12% target if you work at it.
To avoid constantly going to the weigh station, you can create a weigh station of your own using the heavy duty scale method in the attachment.
Secondly, a previous poster suggested that the rear axle weight may be the real limiting factor for us. My manual says the tongue weight may add more than 1 1/2 times its weight to the rear axle - for example that an 800 pound tongue could add 1200 pounds to the axle. If so, that will be a real problem for our car. Does the equalizer hitch help with this at all?
The maximum tongue weight is that allowable amount of load that can be placed on the hitch attachment points; not the rear axle.
The amount of weight carried by each axle is determined by where the total load on your vehicle is placed. A weight distributing hitch will allow you to "carry" your tongue weight "distributed" among all the axles in contact with the ground; typically shifting the weight normally carried by the rear axle onto the front and camper axles.
The max camper and tongue weight we calculated REQUIRES a WD hitch. Get one with integrated sway control (like a 4 point Equil-i-zer hitch or similar). Make sure the rating on the hitch is higher that your maximum camper weight. Going way over could be problematic for you, since the larger capacity hitches are slightly heavier.
Equal-i-zer Hitch 1000/10000lbs Trailer Weight - RVWholesalers.com RV Parts
Or the 12,000 pound one
Equal-i-zer Hitch 1200/12000lbs Trailer Weight - RVWholesalers.com RV Parts
Remember that the weight of the hitch head is NOT part of the tongue load (part of the TV weight); but the bars and trailer frame clamps are.
__________________
Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
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05-20-2012, 06:35 AM
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#30
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Moderator Emeritus
Join Date: Aug 2010
Location: Southeast Wisconsin
Posts: 6,949
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Hi Nancy,
Lots of ways to move your cargo around to effect the TW with some trailers being easier to load differently than others. You can also effect it by the volume in your tanks, depending where they are in relation to your trailer axles. For instance, my FW tank is right in front of my axles so a load of water will add TW.
As for the axle question, an 800 lb tongue weight with a weight distribution hitch cannot add 1200 lbs to the rear axle. It can only add up to 800lbs (no WDH or bars unhooked). With the WDH engaged, the load on the rear axle will be less than 800lbs. How much less depends on the tension on the bars with greater tension placing more force onto the truck's front axle and the trailer's axles. If you can revisit the towing calculator, than you can plug in your axle ratings and weights to be sure these are not overloaded.
__________________
Scott
DW, 3 Kids and our Goldens
2012 Shamrock 233S
2008 Toyota Sequoia 5.7L 4WD
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05-20-2012, 09:05 AM
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#31
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Junior Member
Join Date: May 2012
Location: Texas
Posts: 17
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Thanks Herk and Triguy. The heavy weight scale set up looks like something we will use. The only public scale we could find was quite a drive. Husband spent time yesterday getting on and off the bathroom scales hefting stuff we keep in our existing camper. I am considering getting one of those hand held scales you can use to weigh your luggage. I could use it to assess weight of items being added to camper. He is planning on the Equalizer hitch - at least the 10,000. Really glad to know that hitch will prevent all the tongue weight from going onto the rear axle. The rear axle is rated at 4100, and the front axle rating is 3550. When we weighed the car yesterday, the load on the rear axle was 2800 and on the front axle was 3020. That was with me in the car. We would be adding another 450 pounds of people and stuff to the car, and a tongue of 770-800. I will look at the calculator again to see how that shakes out.
By the way, I just want to say thanks again for all the info you have shared. It is amazing to me (and husband didn't want to believe it) that despite our car having a "tow rating of 7,900 lbs", and having a powerful engine, we can't tow nearly that much. The limiting factor on our vehicle is the 7,100 GVWR - and the fact that the car itself is so heavy really decreases what we can tow. Hope people look past that "tow rating" when considering the kind of camper they can tow. You guys were also right that the listed weight of the camper in the brochure is lighter than the actual weight. Every single one of the units we have seen like ours arrives at the dealer with a yellow sticker that is about 300lbs more than the listed weight.
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05-20-2012, 09:29 AM
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#32
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Moderator Emeritus
Join Date: Aug 2010
Location: Southeast Wisconsin
Posts: 6,949
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You're doing a great job checking your weight and ratings. I know this is a lot of work now, but you will feel good about your setup later on.
__________________
Scott
DW, 3 Kids and our Goldens
2012 Shamrock 233S
2008 Toyota Sequoia 5.7L 4WD
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05-20-2012, 01:44 PM
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#33
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Site Team
Join Date: Jan 2007
Location: Goodyear, Arizona
Posts: 33,776
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i commend you on all the work you're doing to understand and learn about this.
many won't go to all the trouble that you are and just hook up things and take off, endangering themselves, their family and others on the road.
most members of the "weight police" are really trying to keep others safe, not because they think that you need a 1 ton dually to pull a popup.
__________________
Dan-Retired California Firefighter/EMT
Shawn-Musician/Entrepreneur/Wine Expert
and Zoe the Wonder Dog(R.I.P.)
2016 PrimeTime TracerAIR 255, pushing a 2014 Ford F150 SCREW XTR 4x4 3.5 Ecoboost w/Max Tow Package
4pt Equal-i-zer WDH and 1828lbs of payload capacity
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05-20-2012, 08:32 PM
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#34
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Moderator Emeritus
Join Date: Sep 2008
Location: Shenandoah Valley of Virginia
Posts: 9,280
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Quote:
Originally Posted by herk7769
A weight distributing hitch will allow you to "carry" your tongue weight "distributed" among all the axles in contact with the ground; typically shifting the weight normally carried by the rear axle onto the front and camper axles.
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As Lou stated, the weight is distributed around all axles. Weight is taken off of the rear TV axle, and that is put on the front TV axle and the trailer axles. In my case, 120 lbs. is transferred to the trailer axles....which means that weight is no longer carried by my truck. That gives me another 120 lbs. of leeway before I reach my GVWR. Your results should be similar.
__________________
Chap , DW Joy, and Fur Baby Sango
2017 F350 Lariat CCSB, SRW, 4x4, 6.7 PS
2017 Grand Design Reflection 337RLS
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05-21-2012, 06:16 AM
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#35
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Site Team - Lou
Join Date: Oct 2009
Location: South Eastern PA
Posts: 23,269
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Quote:
Originally Posted by mtnguy
That gives me another 120 lbs. of leeway before I reach my GVWR. Your results should be similar.
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Chap, I do not believe that is the case. Remember that the tongue load is still on the frame due to the forces involved being levered across the fulcrum of the ball. In most cases (I would have said ALL but...) the frame is the limiting factor when determining GVWR.
If you put a lever on a load and pry downward, the prying force is multiplied at the point of the load but the fulcrum carries 100 percent of the applied force.
This is also why three weighs are required; truck alone, hitched to camper with WD bars in place and without.
__________________
Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
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05-21-2012, 08:42 AM
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#36
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Moderator Emeritus
Join Date: Sep 2008
Location: Shenandoah Valley of Virginia
Posts: 9,280
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Quote:
Originally Posted by herk7769
Chap, I do not believe that is the case. Remember that the tongue load is still on the frame due to the forces involved being levered across the fulcrum of the ball. In most cases (I would have said ALL but...) the frame is the limiting factor when determining GVWR.
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Lou, I am going to have to respectfully disagree, due to observing my own weight stats found here: http://www.forestriverforums.com/for...ats-11523.html
My truck and trailer without spring bars attached: 6840 lbs.
My truck and trailer with spring bars attached: 6720 lbs.
My truck is now 120 lbs. lighter with the spring bars attached.
My trailer has gained 140 lbs. when the spring bars are attached.
Where is that extra 20 lbs. difference (140 vs. 120) ?? That is due to to a scale with only 20 lb. increments...which is probably the standard for truck scales.
Even with the diagram that was attached, it shows the front axle gaining 612 lbs., and the rear losing 912 lbs. with the WDH. Where does that 300 lb. difference go ?? The diagram shows the trailer axle gaining 300 lbs.
Quote:
Originally Posted by herk7769
If you put a lever on a load and pry downward, the prying force is multiplied at the point of the load but the fulcrum carries 100 percent of the applied force.
This is also why three weighs are required; truck alone, hitched to camper with WD bars in place and without.
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Agreed. But you have to calculate in the downward force being applied as a factor.
__________________
Chap , DW Joy, and Fur Baby Sango
2017 F350 Lariat CCSB, SRW, 4x4, 6.7 PS
2017 Grand Design Reflection 337RLS
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05-22-2012, 07:27 AM
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#37
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Site Team - Lou
Join Date: Oct 2009
Location: South Eastern PA
Posts: 23,269
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MTNGUY,
I know we have been discussing this in PM, but I need to post a graphic and that is a limitation of PM. We were using a "wheel Barrow" analogy to explain each other's logic regarding why the I feel the stress of the load on the TV without WD bars stays the same even thought some of the weight is transferred to the axles of the camper via the WD hitch.
In the graphic, just because the dude picks up 25 pounds of the load of the wheel barrow, does not mean IMO, that the wheel barrow can carry more "stuff" since the frame of the wheel barrow's weight limit is still 100 pounds.
__________________
Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
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05-22-2012, 11:57 AM
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#38
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Junior Member
Join Date: May 2012
Location: Texas
Posts: 17
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Wow! When you guys get this figured out (I am sure you will!) I hope you will let me know of any impact on my set up. I can't weigh axles until my new Rockwood arrives and we load it up. But will then see where we are.
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05-22-2012, 03:09 PM
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#39
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Moderator Emeritus
Join Date: Sep 2008
Location: Shenandoah Valley of Virginia
Posts: 9,280
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Lou, that is an excellent diagram…..even “diagram man” moves his arms !!!
Like Lou said, we have been having a friendly little “convince me” debate in between working on our home obligations. Already, I have discovered that the fulcrum point moves to the front axle when using a WDH….I had never thought about that before.
When someone places a trailer tongue on a hitch, that is a Class 1 lever……….the effort (trailer tongue) is trying to lift the front axle (resistance), and the back axle act like a fulcrum. See the 3rd diagram down on the right here: Lever - Wikipedia, the free encyclopedia The front axle gets lighter, and the rear axle gets the weight lost from the front axle, plus the weight of the trailer tongue. Using my combination as an example (rounded off for simplicity), putting 700 lbs. on my hitch (effort) takes 300 lbs. off my front axle (resistance), and puts 1000 lbs. on my rear axle (fulcrum).
But when a WDH is used, the front axle becomes the fulcrum point like in a Class 2 lever……the rear axle is the resistance, and the WDH is the effort. The wheel barrow in Lou’s diagram is an excellent example.
Comparing the wheelbarrow to our rigs:
Wheelbarrow front axle = tow vehicle front axle
Wheelbarrow legs = tow vehicle rear axle
The Wheelbarrow handles = hitch
“Diagram Man” arms = both trailer tongue and WDH
“Diagram Man” feet = trailer axles
If the dude pushes down on the wheelbarrow handles, that effort is going to try to lift the wheel off of the ground. Because he is pushing down, his feet will get lighter and that difference will be transferred to the wheel barrow, putting that over the 100 lb. weight limit. Our trailer axles do not get lighter when we hook up, because the weight is already on the tongue, and supported by the jack or hitch ball.
But if Diagram Man picks up on the handles, his arms now acts like a WDH….some of that 100 lbs. of weight is transferred to the wheel (tow vehicle front axle), and I think (hence some of the discussion and debate) some of the weight goes to the dudes feet….the effort to raise handles. Again to simplify, since there are some lever length issues (wheelbase), if the dude lifts the legs off of the ground, then I think ~25 lbs. will be added to the wheel, and ~25 lbs. to the guy’s feet. If you set just the wheelbarrow on a set of scales, you would have 75 lbs. on the front wheel, plus 0 lbs. on the legs, resulting in a 25 lb. lose of weight. You could now add another 25 lbs. to the wheelbarrow without exceeding the GVWR.
Now we come back to Lou’s diagram and question……there is 100 lbs. of load in the wheelbarrow, but a set of scales will only show the wheelbarrow weighing 75 lbs. If the 100 lb. load limit is the frame itself, then that wheelbarrow is at its limit. But if the load limit is the wheel (say 100 lbs. GAWR) then you should be able to add 25 lbs more weight to the load. But that is a Class 2 lever.
With our vehicles, we are using 2 forces….a Class 1 lever when we put the trailer tongue on the hitch, and an Class 2 lever when we use a WDH. I am thinking because the WDH takes the weight off of the tow vehicle and putting it back on the trailer axles, then that frees up some extra weight capacity on the tow vehicle. In using a WDH, the truck frame does not "see" the tongue weight....it only "sees" the tongue weight minus the weight being relieved by the WDH. I think that is what Lou and I have been trying to figure out.
Hope all of that convoluted explanations, out loud thinking, and questions make sense, because I think I confused myself.
If there is an engineer in the house, you are welcome to join in.
I think my head hurts.
__________________
Chap , DW Joy, and Fur Baby Sango
2017 F350 Lariat CCSB, SRW, 4x4, 6.7 PS
2017 Grand Design Reflection 337RLS
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05-22-2012, 03:48 PM
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#40
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Site Team - Lou
Join Date: Oct 2009
Location: South Eastern PA
Posts: 23,269
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Quote:
Originally Posted by mtnguy
If you set just the wheelbarrow on a set of scales, you would have 75 lbs. on the front wheel, plus 0 lbs. on the legs, resulting in a 25 lb. lose of weight. You could now add another 25 lbs. to the wheelbarrow without exceeding the GVWR.
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But my point is that for the frame the weight is not "lost;"it is still there right between the wheel and the legs; resting on the frame.
Quote:
Originally Posted by mtnguy
Now we come back to Lou’s diagram and question……there is 100 lbs. of load in the wheelbarrow, but a set of scales will only show the wheelbarrow weighing 75 lbs. If the 100 lb. load limit is the frame itself, then that wheelbarrow is at its limit.
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Exactly.
Quote:
Originally Posted by mtnguy
But if the load limit is the wheel (say 100 lbs. GAWR) then you should be able to add 25 lbs more weight to the load. But that is a Class 2 lever.
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In my example I put the load as an average across the wheel barrow. In reality many loads are distributed across the frame adding up to the total load. For example a diesel engine weighs much more than a gas engine and the front axle of a diesel truck is much closer to its max load than a gas truck.
So if the 100 pounds in the wheel barrow was located as a point load ON the front axle; the legs would carry zero weight and diagram dude flip it over with one finger.
So, the bottom line is, IMO, that the frame sees the entire load regardless of how it is finally distributed across the potential supports (axles; legs; or feet).
I think we should let the readers decide for themselves and put the Physics textbooks away.
PS for Chap - I got my security camera system up and running through all of this. I can now watch my cameras over the Internet on our iPad. My problem turned out to be a conflict in port 80 in the router as it had already locked it out for use by the network storage drive. The iPhone app could not use port 1024 (I selected this in port 80's place) so until I disabled the NAS and reserved port 80 for the camera DVR the iPhone/iPad app was kicking my butt.
__________________
Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
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