Go Back   iRV2 Forums > TRAVEL TRAILER, 5th WHEEL & TRUCK CAMPER FORUMS > Trailer Towing and Tow Vehicles Discussion
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 03-16-2016, 09:37 AM   #15
Senior Member
 
Join Date: Nov 2013
Location: Elko, Nv
Posts: 492
What size is the trailer ? Enclosed ? I had a 6x12 enclosed with the spare mounted up high in the back and had no issues loading bikes, my Harley included. I staggered the bikes in the trlr so if loading 2 big bikes i would load the 2nd bike on the opposite side of the spare. Since i carried varied number and size bikes i had wheel chock mounts located in a few diffent spots. I now have a 8.5x20 enclosed and still have multiple chock mount locations to use depending on what we bring with us.
__________________

__________________
NevadaNick is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 03-16-2016, 07:29 PM   #16
Member
 
Join Date: Mar 2016
Posts: 34
Quote:
Originally Posted by Breezyman View Post
If I mount the spare tire in the rear, I don't have room to get two rather large bikes in and out.

I'm curious as to your recommendation about not counting the tongue in the percentage. Why is that? My whole purpose in these calculations is to establish an axle position which gives me an acceptable tongue weight, as a percentage of loaded trailer weight, under the loaded conditions I am likely to incur.
Nick is correct. The weight of the tongue (the material used to make up the tongue) does not really influence the finished tongue weight of the trailer unless you start adding things to the tongue like tool boxes, propane, batteries etc. If you were going to permanently mount something like a generator or welder to the tongue, then you need to figure in the weight.
__________________

__________________
eipo is offline   Reply With Quote
Old 03-16-2016, 08:48 PM   #17
Senior Member
 
CoachC's Avatar


 
Join Date: May 2015
Posts: 201
I get the weight X Arm= Moment, total weight/total moment = CG. That seems like a lot of work.
Not sure how far forward or aft you can load the cycles but around 437 pounds of tongue weight would be around 12.5% of 3500#. If you have access to a scale perhaps move the load for and aft to find your target % weight.

Good luck.

CoachC
__________________
Rick & Sue
2005 Kountry Star 3907 DP, Spartan MM
Stick built in Michigan but the MH gives us a really big back yard!
CoachC is offline   Reply With Quote
Old 03-17-2016, 07:58 AM   #18
Junior Member
 
Join Date: Mar 2016
Posts: 10
Quote:
Originally Posted by eipo View Post
Nick is correct. The weight of the tongue (the material used to make up the tongue) does not really influence the finished tongue weight of the trailer unless you start adding things to the tongue like tool boxes, propane, batteries etc. If you were going to permanently mount something like a generator or welder to the tongue, then you need to figure in the weight.
Not sure what you're trying to say here. . If you say the material used to make up the tongue doesn't influence TW, you're saying that if I remove the material used to make up the tongue, there will be no difference. I disagree.

The empty trailer has a TW of "X". If I place "Y" lbs. of weight in the trailer anywhere but over the axle it will affect the TW to some degree, depending on the distance I place it away from the axle.

The tongue doesn't care or know whether I place a weight inside a box or outside it. It only cares where I put it in relation to the axle. In front of the axle increases TW, aft decreases TW.
__________________
Breezyman is offline   Reply With Quote
Old 03-17-2016, 08:08 AM   #19
Junior Member
 
Join Date: Mar 2016
Posts: 10
Quote:
Originally Posted by CoachC View Post
I get the weight X Arm= Moment, total weight/total moment = CG. That seems like a lot of work.
Not sure how far forward or aft you can load the cycles but around 437 pounds of tongue weight would be around 12.5% of 3500#. If you have access to a scale perhaps move the load for and aft to find your target % weight.

Good luck.

CoachC
The aft-most bike is 5" from the ramp door and I don't want to be any closer. At that loaded position, with a single 835 lb. bike, the weight is 2445 lbs. and the TW is 17%. And, as you can imagine, adding another bike, which will have to be a minimum of 13" further forward of the first, just aggravates the problem.
__________________
Breezyman is offline   Reply With Quote
Old 03-17-2016, 11:07 AM   #20
Senior Member
 
Join Date: Mar 2013
Posts: 514
Calculating the tongue weight is possible.

Use the aircraft method to find the CG. I'll assuming the CG is measured from the ball mount center, because the aircraft method calculated CG from the propeller. At that point, you'll also have:
- the total gross weight of the trailer, GW
- wheelbase of trailer (distance from ball mount center to axle center), WB

Tongue Weight, TW = GW * (WB-CG)/WB.

To test a formula, look at the extremes: If the CG is over the axle, no tongue weight at all. If the CG is at the tongue (CG=0), the TW = GW. If CG > WB, the tongue weight goes negative which can happen.
__________________
cwsqbm is offline   Reply With Quote
Old 03-17-2016, 12:44 PM   #21
Senior Member
 
Outdoors RV Owners Club
Join Date: Dec 2014
Location: Nowhere, now here. Freedom!
Posts: 2,999
If you're gonna go to scale to get the gross trailer weight (necessary for the aircraft method of determining CoG), might as well just not employ the WD of the hitch, weigh the rear truck axle, then drop the trailer and weigh the rear truck axle again.

Boom, tongue weight, practically applied.

Of course as soon as you add anything to the trailer, like water, beer, hostages, etc., everything changes. Especially if you don't tie the hostages down so they don't move around.

Yeah, I grew up with an engineer that was good at math, but I'm not so good with math as a pure numbers kind of thing. I am fairly good at solving practical math problems, and what I wrote above is one of those ways that I would spin dad's number muddled head.
__________________
ORV 19B Full Timer, '14 Ram 2500 Diesel and a GSD. This signature updated, May 1, '17.
Currently funemployed in Vancouver WA de K7NOL 146.52Mhz Safety? (CLICK ME!)
1bigmess is offline   Reply With Quote
Old 03-17-2016, 03:19 PM   #22
Senior Member
 
CoachC's Avatar


 
Join Date: May 2015
Posts: 201
Quote:
Originally Posted by Breezyman View Post
The aft-most bike is 5" from the ramp door and I don't want to be any closer. At that loaded position, with a single 835 lb. bike, the weight is 2445 lbs. and the TW is 17%. And, as you can imagine, adding another bike, which will have to be a minimum of 13" further forward of the first, just aggravates the problem.
Understand. Didn't know how much for/aft room you had to work with. I assume there is not enough width to load diagonally to get the weight back a bit. Moving the axle or trading for a bigger trailer seem like your choices.
I would concur that staying in the 10-15% range is good once loaded. I don't recall seeing anyone recommend to exceed 20% but I am certainly no expert.

Best regards.
__________________
Rick & Sue
2005 Kountry Star 3907 DP, Spartan MM
Stick built in Michigan but the MH gives us a really big back yard!
CoachC is offline   Reply With Quote
Old 03-17-2016, 03:29 PM   #23
Senior Member
 
Join Date: Mar 2013
Posts: 514
Quote:
Originally Posted by 1bigmess View Post
If you're gonna go to scale to get the gross trailer weight (necessary for the aircraft method of determining CoG), might as well just not employ the WD of the hitch, weigh the rear truck axle, then drop the trailer and weigh the rear truck axle again.

Boom, tongue weight, practically applied.
Most truck scales have three sections - steer, drive, and trailer. To weigh my trailer, I pull in (WD disconnected before hand) to where the truck's tires are just off the scale. I lift the tongue until it comes off the ball, and then hit the call button for a weigh. The trailer's tires on the middle plate, and the tongue jack on the front plate. I get it all in one shot.
__________________
cwsqbm is offline   Reply With Quote
Old 03-17-2016, 05:16 PM   #24
Senior Member
 
Join Date: Jan 2016
Posts: 342
Too much math for me. I've built a couple trailers. I built two of them using the 55-45% deal and they worked great. A local trailer builder makes a model like yours with a 70-30% ratio with a very heavy frame. These are made for contractors and such to haul bricks and such. I'd say just move your axle to the 60-40% or 55-45% position as a benchmark and go from there.
BTW one small electric wheel chair trailer I built the customer refused to allow me to have the axle mounted rearward as the design dictated. Due to the folding ramp I built for it it had a negative hitch weight of 40-50 lbs when loaded. LOL I bolted counter weights to the front of the trailer frame. Problem solved. He was happy.
__________________
Bob1340 is offline   Reply With Quote
Old 03-17-2016, 05:27 PM   #25
Member
 
Join Date: Mar 2016
Posts: 34
Quote:
Originally Posted by Breezyman View Post
Not sure what you're trying to say here. . If you say the material used to make up the tongue doesn't influence TW, you're saying that if I remove the material used to make up the tongue, there will be no difference. I disagree.
Thats not what I said. I said the material that makes up the tongue does not have a significant impact on tongue weight. And most people do not load the tongue, they load the cargo area. By not using the length of the tongue in your axle placement you are always guaranteed to have tongue weight when unloaded. If you include the relatively light tongue length in your axle placement decision you will end up with either no tongue weight or not enough when unloaded.

Quote:
Originally Posted by Breezyman View Post
The empty trailer has a TW of "X". If I place "Y" lbs. of weight in the trailer anywhere but over the axle it will affect the TW to some degree, depending on the distance I place it away from the axle.

The tongue doesn't care or know whether I place a weight inside a box or outside it. It only cares where I put it in relation to the axle. In front of the axle increases TW, aft decreases TW.
Which is why I said the only time you need to include the tongue length in your axle placement is if you are going to permanently mount something of substantial weight on the tongue, ahead of the cargo area.
__________________
eipo is offline   Reply With Quote
Old 03-17-2016, 09:38 PM   #26
Senior Member
 
Join Date: Nov 2013
Location: Elko, Nv
Posts: 492
Think of it this way, you have a teeter totter that is centered on the axle. There is a set amount of weight in front of the axle and the only area you have that influences the teeter totter is the loadable area of the trailer which is not the toungue unless you plan to put something on the toungue.
__________________
NevadaNick is offline   Reply With Quote
Old 03-18-2016, 12:06 PM   #27
Junior Member
 
Join Date: Mar 2016
Posts: 10
Quote:
Originally Posted by cwsqbm View Post
Calculating the tongue weight is possible.

Use the aircraft method to find the CG. I'll assuming the CG is measured from the ball mount center, because the aircraft method calculated CG from the propeller. At that point, you'll also have:
- the total gross weight of the trailer, GW
- wheelbase of trailer (distance from ball mount center to axle center), WB

Tongue Weight, TW = GW * (WB-CG)/WB.

To test a formula, look at the extremes: If the CG is over the axle, no tongue weight at all. If the CG is at the tongue (CG=0), the TW = GW. If CG > WB, the tongue weight goes negative which can happen.
Having been a Flight Engineer and a Pilot, I have been using the aircraft method.
__________________
Breezyman is offline   Reply With Quote
Old 03-19-2016, 09:45 AM   #28
Senior Member
 
Join Date: Nov 2013
Location: Elko, Nv
Posts: 492
Your aircraft method will not work if calculating from the ball mount, you need only calculate the loadable area. Put a scale under the toungue jack and load some weight in the trailer using your method and then using only loadable area and you will see what i mean.
__________________

__________________
NevadaNick is offline   Reply With Quote
Reply

Tags
tongue weight, weight



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Receiver hitch weight & tongue weight 1010 Trailer Towing and Tow Vehicles Discussion 36 03-02-2014 12:33 AM
'89 Crown Royale towing/tongue weight Devin W Monaco Owner's Forum 2 02-26-2009 04:58 PM
Tongue weight Ron & Dee Workhorse and Chevrolet Chassis Motorhome Forum 13 06-05-2007 05:18 AM
tongue weight jbeck Newmar Owner's Forum 3 02-07-2006 09:12 AM
tongue weight jbeck Newmar Owner's Forum 2 01-26-2006 05:10 PM

» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 12:08 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.