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07-08-2006, 11:47 AM
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#1
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Rivet Master
2006 25' Safari FB SE
St. Cloud
, Minnesota
Join Date: Aug 2003
Posts: 13,280
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Hitch weight with a bathroom scale
We've talked about this method and the diagram is in many Airstream manuals. I think it is high time we had a better point of reference in the Forums. This will be a how-to for using simple materials and a bathroom scale to weigh the hitch (a.k.a. tongue) weight. Refer to the diagram attached to this post.
Do this only with the trailer on level ground and wheels chocked. Make sure the scale is capable of weighing at least 250 pounds (300# better). You can weigh 2 to 4 times the scale capacity with this setup, therefore you might be able to make this measurement for up to a 30-footer depending on vintage (newer trailers being much heavier). Refer to Airstream's FAQ page numbers on your trailer's curb weight (without options). This simple measurement will help you understand where your tongue weight falls in relation to the empty trailer number. For real world relevance I would advise having WD gear & your bars on the A frame, having LP in the tanks, and even taking the hitch bar/ball off your TV and setting it on the A frame too (we are aiming for the tongue weight load imposed on your TV after all). Whether you have any personal items in the trailer is up to you -- just factor in an allowance if the trailer is empty. Weighing at a CAT truck scale should be more accurate than a bathroom scale; use the search function if you want to find more on that.
These instructions from Draw-Tite are clear and I don't want to put this off until I can retrieve the manual from our stored trailer.
"Tongue weight (TW) is the downward force exerted on the hitch ball by the trailer coupler. In most cases, it is about 10 to 15 percent of GTW. TW of up to 300 lbs. can be measured on a household scale by resting the trailer coupler on the scale and placing the scale on a box so that the coupler is at its normal towing height. The trailer must be fully loaded and level.
"For heavier tongue weights, place a household scale and a brick that's as thick as the scale three feet apart as shown in Figure 2. Set a length of pipe on each and rest a beam across the pipes. Re-zero the scale to correct for the weight of the beam and pipe. Securely block the trailer wheels. Rest the trailer jack on the beam as shown, one (1) foot from the brick and two (2) feet from the scale.
"To obtain the TW, multiply the scale reading by three (3). For greater tongue weights, place the scale and brick four (4) feet apart, rest the jack on the beam three (3) feet from the scale and multiply the scale reading by four (4)."
Be sure and use beefy enough lumber and maybe put a piece of plywood on your bathroom scale to spread out the forces concentrated under the pipe.
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07-08-2006, 12:00 PM
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#2
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Patriotic
1973 23' Safari
North of Boston
, Massachusetts
Join Date: May 2002
Posts: 4,546
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what's the pipe for?
can't really see it in the drawing, either.
__________________
Air:291
Wbcci: 3752
'73 Safari 23'
'00 Dodge Ram 1500 4x4 QC
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07-08-2006, 12:03 PM
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#3
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Rivet Master
2006 25' Safari FB SE
St. Cloud
, Minnesota
Join Date: Aug 2003
Posts: 13,280
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Due to the widths of the scale and brick, the two pieces of pipe allow a very measured fulcrum point to be set up so that the geometry allows accurate weights. Honestly, I don't think you'd be off much if you ripped a 3/4" square length of wood to substitute for the pipe.
I can probably say I wouldn't put the pipe on a brick unless there was plywood underneath to spread forces. Probably better to skip the brick if you just stacked wood pieces until you equalled the height of the bathroom scale. Also -- put the scale on some solid surface, not sand it might sink into.
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07-08-2006, 03:47 PM
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#4
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Rivet Master
1978 31' Excella 500
Venice
, California
Join Date: May 2006
Posts: 1,067
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If you want to get crazy, you could substitute two pieces of angle iron for the two pipes. Place them open side down and you have two knife edges!
__________________
"Not all who are laundering are washed" say Bill & Heidi
'78 Excella 500,"The Silver Pullit". vacuum over hydraulic disc brakes, center bath, rear twin. '67 Travelall 1200 B 4X4 WBCCI 3737
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07-08-2006, 10:50 PM
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#5
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Rivet Master
1960 24' Tradewind
santa barbara
, California
Join Date: Apr 2006
Posts: 1,352
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hello canoestream ,
The bathroom scale things seems kinda kooky ,but I did try it with my 60
trdwnd and the tongue weight as listed in the airstream archives trailer
weights show 310# and I measured 320# so pretty close .Haven't tried it
ready to go though. When I get a chance sometime .
Scott
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07-09-2006, 09:41 PM
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#6
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Rivet Master
2006 25' Safari FB SE
St. Cloud
, Minnesota
Join Date: Aug 2003
Posts: 13,280
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Thanks for giving us some real-world results Scott. I will weigh my 25' Safari next weekend and report results here. Anybody else?
I feel that something approaching loaded tongue weights could be a surprise to some readers if they rely on the specifications published in their owners manual or at airstream.com. Those specifications do say that it is for the unloaded trailer without options; for instance, the current Safari LS package (which I have) does include a spare tire that is located very close to the underside front of the trailer.
Stay tuned.
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07-10-2006, 12:36 PM
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#7
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Rivet Master
1951 21' Flying Cloud
1960 24' Tradewind
West Coast
, BC
Join Date: Feb 2005
Posts: 3,790
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Lessons learned:
1. If you are using the scales out of the ensuite, those would be the formerly all white ones, consider wrapping them in something to protect them from scratches and put something under them so dirt does not get caught up in the no slip pad on the bottom.
2. If you are using those same scales, before you put them back, clean them and then clean them some more, remove as many of the "oops" as you can, and get them back into the exact same spot BEFORE your spouse (wife) comes home. Particularly if said spouse has a known "everything must be clean and orderly" fetish.
3. It is not advisable, when said spouse goes to use the weigh scales and notices they have been used in a manner that does not fit with her Clean Homes and Orderly Gardens weigh scale usage criteria, to suggest that perhaps the scuff marks are because she's maybe gained a few pounds and is now putting a tad more stress on the old scales. Other no-no comments would be how surprised you are that they've survived as long as they have, or musta been when her mom/sister etc was out visiting.
4. It is important to note here that it is almost impossible to dodge a set of weigh scales coming at high velocity in the limited confines of the ensuite after any of the statements in #3 are vocalized. It doesn't matter how fast you think you are. There's a unique ricochet effect that comes into play that said spouse seems to be well versed in - I think they learned that in HomeEc in school. It can be deadly!
5. Be prepared to purchase a new set of weigh scales and there's always the probability of wall repair (glancing blow) and bruising. As for eardrums, I'm told that eventually they may heal.
Solution: Borrow your neighbours. Don't tell him why. Let him live with the consequences. It's one way to get even for all those tools he's borrowed and "forgotten" to return.
Barry
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07-10-2006, 01:17 PM
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#8
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Patriotic
1973 23' Safari
North of Boston
, Massachusetts
Join Date: May 2002
Posts: 4,546
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good tips!!
you may also want to "re-zero" the scale when you're done, should you choose to forego the previous advice...
__________________
Air:291
Wbcci: 3752
'73 Safari 23'
'00 Dodge Ram 1500 4x4 QC
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02-14-2010, 08:31 AM
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#9
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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Quote:
Originally Posted by safari57
Lessons learned:
1. If you are using the scales out of the ensuite, those would be the formerly all white ones, consider wrapping them in something to protect them from scratches and put something under them so dirt does not get caught up in the no slip pad on the bottom.
2. If you are using those same scales, before you put them back, clean them and then clean them some more, remove as many of the "oops" as you can, and get them back into the exact same spot BEFORE your spouse (wife) comes home. Particularly if said spouse has a known "everything must be clean and orderly" fetish.
3. It is not advisable, when said spouse goes to use the weigh scales and notices they have been used in a manner that does not fit with her Clean Homes and Orderly Gardens weigh scale usage criteria, to suggest that perhaps the scuff marks are because she's maybe gained a few pounds and is now putting a tad more stress on the old scales. Other no-no comments would be how surprised you are that they've survived as long as they have, or musta been when her mom/sister etc was out visiting.
4. It is important to note here that it is almost impossible to dodge a set of weigh scales coming at high velocity in the limited confines of the ensuite after any of the statements in #3 are vocalized. It doesn't matter how fast you think you are. There's a unique ricochet effect that comes into play that said spouse seems to be well versed in - I think they learned that in HomeEc in school. It can be deadly!
5. Be prepared to purchase a new set of weigh scales and there's always the probability of wall repair (glancing blow) and bruising. As for eardrums, I'm told that eventually they may heal.
Solution: Borrow your neighbours. Don't tell him why. Let him live with the consequences. It's one way to get even for all those tools he's borrowed and "forgotten" to return.
Barry
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Busted twice... not worth the legal feez
Exactly why I chew's this solution....
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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02-14-2010, 09:02 AM
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#10
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Rivet Master
Port Orchard
, Washington
Join Date: May 2009
Posts: 4,463
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Quote:
Originally Posted by CanoeStream
Due to the widths of the scale and brick, the two pieces of pipe allow a very measured fulcrum point to be set up so that the geometry allows accurate weights. Honestly, I don't think you'd be off much if you ripped a 3/4" square length of wood to substitute for the pipe.
I wouldn't put the pipe on a brick unless there was plywood underneath to spread forces. Probably better to skip the brick if you just stacked wood pieces until you equalled the height of the bathroom scale. Also -- put ]
the scale on some solid surface, not sand it might sink into.
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I certainly would replace the pipes with something that won't roll. No matter how well you chock the tires and check for level, anyone or anything bumping into the tongue, could cause the pipes and board to roll off the brick and scale.
However even better: I would spring for the little over a hundred bucks and buy a Sherline tongue weight scale ( Sherline Direct: LM1000/LM2000/LM5000 - Sherline Trailer Tongue Weight Scale ) and do the job properly and accurately. You will probably want to do it more than once.
Regards,
Ken
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02-14-2010, 09:40 AM
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#11
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Rivet Master
Airstream Dealer
Corona
, California
Join Date: Feb 2002
Posts: 16,497
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The bathroom scale works ok with single axle trailers, but presents a problem when attempting to weigh the tounge weight of a tandem axle trailer, along with most any other scale.
A tandem axle trailer, must be perfectly level, in order to obtain the correct tongue weight.
If the front of the trailer is higher than level, the weight reading will be higher than the actual true tongue weight.
Also, if the front of the trailer is lower than level, the weight reading will be lower than the actual true tongue weight.
Andy
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02-14-2010, 09:56 AM
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#12
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banjobill
2000 30' Limited
battle ground,
, Washington
Join Date: Jun 2009
Posts: 516
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ball park is within reason
to add to what Andy said: I assume ya'll tow with the trailer dead level , but if not quite, be sure to weigh the trailer at the "pitch" it will be at when towing...hook up like you normally do, then measure the height of the coupler off the level ground. Then, when weighing, be sure to have the coupler at that height. Also, remember you are weighing tongue weight at the base of your tongue jack-which is several inches towards the rear of the trailer from the ball coupler, whereas actual tongue weight would be measured directly centered on the coupler. So if you are a mathematician, go for it, if not- ball park is close enough, or, you could build a mechanism to weigh from the coupler center; or you could buy the aforementioned scale...
ol' bill
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02-14-2010, 11:51 AM
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#13
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Rivet Master
Commercial Member
1962 19' Globetrotter
1963 19' Globetrotter
1961 19' Globetrotter
Wheat Ridge
, Colorado
Join Date: Dec 2007
Posts: 624
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I have a easy way to find out both the real trailer and tongue weight and takes about ten minutes to do so! Go to a truck stop and weigh both your TV and trailer at the same time! The scale is made up of several pads about 20' in length make sure that the trailer and TV are on different pads when on scale!!!! Go in and get your scaled weight and then ask for a rescale (this is very common request) They may charge you a buck or two for a rescale. Now go and rescale the TV only and get that weight! Now you have all the info you need!
Because you weighed the TV and trailer together but on different pads the paper work will show the weight of both pads and then the weight of all pads. Now take the weight from the first scale of the first pad of the TV and minus the second weight of TV by it's self and this is your tongue weight. If you minus second weigh of just the TV with the entire weigh of the first weight with both the TV and the trailer this becomes the trailers weight.
You should do this from time to time with your trailer when fully loaded to see if you are loading it right! Remember the rule is that the tongue weight should be 10% of the total weight of the trailer! If more than 10% the TV will have problems front end control and way under 10% the TV will have control problems with backend control.
Todd
__________________
www.VINSTREAM.com
Wheat Ridge, Colorado
WBCCI # 1962
Instagram #Vinstream
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02-16-2010, 03:54 PM
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#14
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Rivet Master
2005 25' International CCD
Fleetwood
, North Carolina
Join Date: Aug 2005
Posts: 687
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No ensuite scales in our house -- don't have the weight capacity for them unless we jettison the bourbon, rum, and gin. Not gonna happen, so no scales.
We stop at truck scales 2-3x per year, and only last year started using the rescale or reweigh ($1 extra). We pull on with truck on two pads and trailer on another. Get one weighing. Then move so hitch and trailer axles are on two separate pads, unhitch, and reweigh.
Allows us to weigh truck with and without trailer, so we understand the loading on truck's axles. And, like you say, gives us separate tongue weight and trailer axle weight. We have a low axle weight rating on the A/S (only 3K each) so need to watch for scope creep.
Worth the $9 or $10 we pay, helps us keep an eye on how much more stuff we're towing than we said we would since last weighing.
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02-16-2010, 06:50 PM
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#15
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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Have you all noticed that everytime you get a CAT re-weight your GVCW is different.
That's why I started using the Sherline Tongue Scale.
Cat, gave me tongue weights between 760-900lb @ the tongue jack.
Sherline, 1055-1200 @ the ball socket. Depending on load....
quite a surprise to say the least.
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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02-19-2010, 12:55 AM
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#16
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Rivet Master
2005 25' International CCD
Fleetwood
, North Carolina
Join Date: Aug 2005
Posts: 687
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Bob, that is a significant difference. Crud. I guess the Sherline would make a fine addition to my gear, cuz I'd be able to tell how many pounds of rocks she stowed under the front sofa.
More seriously, it would be nice to monitor this more accurately then just do one pass through CAT scales for axle weights. I'm looking into the Sherline -- Thanks.
Jim
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02-19-2010, 06:21 AM
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#17
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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[QUOTE=DreamStreamr;811501 I'm looking into the Sherline -- Thanks.
Jim[/QUOTE]
At around $100, it was worth it, gives the option of checking the tongue weight when loading for a trip. Less time at the Cat's when you need only check axle weights.
We now know when to put the junk in the trunk.
For real....it does make it easier to get the balance thing right!!
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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02-19-2010, 08:15 AM
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#18
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4 Rivet Member
1993 30' Excella
Lakeland
, Florida
Join Date: Nov 2009
Posts: 343
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true weights the angle of the fulcrum point
Quote:
Originally Posted by Inland RV Center, In
The bathroom scale works ok with single axle trailers, but presents a problem when attempting to weigh the tounge weight of a tandem axle trailer, along with most any other scale.
A tandem axle trailer, must be perfectly level, in order to obtain the correct tongue weight.
If the front of the trailer is higher than level, the weight reading will be higher than the actual true tongue weight.
Also, if the front of the trailer is lower than level, the weight reading will be lower than the actual true tongue weight.
Andy
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Hi Andy
I knew I shouldn't have gotten a dual axle trailer for more reasons than it costing triple at toll roads.
Would measuring weight at the coupler be accurate if the trailer tongue is at the 19 1/2" recommended level? (assumed level angle)
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02-19-2010, 08:19 AM
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#19
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Wise Elder
2010 30' Classic
Vintage Kin Owner
South of the river
, Minnesota
Join Date: Dec 2009
Posts: 4,169
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Quote:
Originally Posted by Inland RV Center, In
The bathroom scale works ok with single axle trailers, but presents a problem when attempting to weigh the tounge weight of a tandem axle trailer, along with most any other scale.
A tandem axle trailer, must be perfectly level, in order to obtain the correct tongue weight.
If the front of the trailer is higher than level, the weight reading will be higher than the actual true tongue weight.
Also, if the front of the trailer is lower than level, the weight reading will be lower than the actual true tongue weight.
Andy
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You can weigh the trailer at the hitch jack to compensate for this, and add 10% or so for the difference in lever arm.
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02-19-2010, 08:34 AM
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#20
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Rivet Master
1999 23' Safari
Perrysburg
, Ann Arbor
Join Date: Sep 2005
Posts: 916
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Quote:
Originally Posted by DreamStreamr
I'd be able to tell how many pounds of rocks she stowed under the front sofa.
More seriously, it would be nice to monitor this more accurately then just do one pass through CAT scales for axle weights.
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More seriously? See, I've got a DW who collects rocks from all over the world for her garden. She calls it "rock rescue." She thinks Lucy in the Long, Long Trailer is being perfectly rational. In fact, I once came home to fine a 800# rock in the back of the pickup ... she BOUGHT it and got some guy with a major league forklift to put it in the truck - my job: to remove it and put it where it was "supposed to go."
So I'm ALWAYS careful to take a rock inventory before hitching up!
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