Reply
 
Thread Tools Search this Thread Display Modes
 
Old 04-07-2010, 06:07 PM   #43
Well Preserved

 
1993 21' Sovereign
Colfax , North Carolina
Join Date: Jun 2003
Posts: 20,193
Quote:
Originally Posted by gamana View Post
Quite relevant as Airstream did exactly the opposite of my silly idea by adding weight to the tongue instead of removing it.

Another question: does the amount of axles on the trailer reduces sway?
Single axle trailers will tend to sway more than multi-axle trailers.
__________________

__________________
Meddle not in the affairs of dragons, for you are crunchy, and taste good with ketchup.
Terry
overlander63 is offline   Reply With Quote
Old 04-07-2010, 06:21 PM   #44
Site Team
 
, Minnesota
Join Date: Aug 2003
Posts: 6,940
Images: 59
Axles don't reduce sway. Tire sidewall stiffness reduces sway.

More axles = more tires = more sidewall stiffness = less sway.
__________________

__________________
markdoane is offline   Reply With Quote
Old 04-07-2010, 06:34 PM   #45
2 Rivet Member
 
2010 27' FB International
Miami , Florida
Join Date: Feb 2010
Posts: 75
That's what I thought. I always wondered why trailers were not built with two axles far apart with the front axle built on pivot (like a car). It would reduce the sway and lighten the tongue, no?
__________________
gamana is offline   Reply With Quote
Old 04-07-2010, 07:23 PM   #46
_
 
. , .
Join Date: Dec 2004
Posts: 8,812
Quote:
Originally Posted by markdoane View Post
Axles don't reduce sway. Tire sidewall stiffness reduces sway. More axles = more tires = more sidewall stiffness = less sway.

so 6 tires on ONE axle = 6 tires on 3 axles, in relation to sway control or stability?



cheers
2air'
__________________
all of the true things that i am about to tell you are shameless lies. l.b.j.

we are here on earth to fart around. don't let anybody tell you any different. k.v.
2airishuman is offline   Reply With Quote
Old 04-07-2010, 08:15 PM   #47
4 Rivet Member
 
Airstream01's Avatar
 
2008 25' Safari FB SE
Land of fruits and nuts , California
Join Date: Jul 2009
Posts: 291
Go big or go home. All these gimmicks you're thinking of will cost more in the long run and will leave you upside down in a ditch in short order.

Do it right or not at all.
__________________
Airstream01 is offline   Reply With Quote
Old 04-07-2010, 09:29 PM   #48
2 Rivet Member
 
2010 27' FB International
Miami , Florida
Join Date: Feb 2010
Posts: 75
Quote:
Originally Posted by Airstream01 View Post
Go big or go home. All these gimmicks you're thinking of will cost more in the long run and will leave you upside down in a ditch in short order.

Do it right or not at all.
Well, you view it as gimmicks. I view it as thoughts. I am not an engineer, builder or stunt man, I certainly don't like flipping into ditches and, as a matter of fact, I know just about nothing about sway. I would therefore use, like everyone else, a good WD, sway control and TV to tow an AS.

BUT, going back to concepts, considering that all objects in motion tend to sway from outside forces, it is obvious that some objects do better than others in controlling sway. A car, for example, is subjected to the same outside forces than the trailer but it handles sway better. You could say that the car is smaller (lower center of gravity) than the trailer but even if you take a bus the same size as the trailer, it will still handle better.

I could be completely wrong but my guts tell me that the tires in each corner of the car/bus are the main factor as to why the sway is controlled.

Now, why would the principle not be applicable to a trailer?

go ahead. bury me.
__________________
gamana is offline   Reply With Quote
Old 04-07-2010, 09:58 PM   #49
tpi
Rivet Master
 
2005 25' Safari
Trabuco Canyon , California
Join Date: Apr 2006
Posts: 866
Images: 2
I believe one of the reasons axles/tires are located close together on a trailer is they would simply scrub and scuff way too much in turns if they were located out at the corners. A car's front wheels steer so that isn't a problem.
__________________
tpi is offline   Reply With Quote
Old 04-07-2010, 10:05 PM   #50
2 Rivet Member
 
2010 27' FB International
Miami , Florida
Join Date: Feb 2010
Posts: 75
Quote:
Originally Posted by tpi View Post
I believe one of the reasons axles/tires are located close together on a trailer is they would simply scrub and scuff way too much in turns if they were located out at the corners. A car's front wheels steer so that isn't a problem.
true, unless the front axle of the trailer is also on a pivot, similar to those big farm trailers.
__________________
gamana is offline   Reply With Quote
Old 04-07-2010, 10:44 PM   #51
Rivet Master
 
hampstead38's Avatar
 
1967 26' Overlander
Upperco , Maryland
Join Date: Jun 2008
Posts: 1,087
Blog Entries: 22
There are trailers with wheels at "the four corners." In this country, we call them "hay wagons." The small version are called "little red wagons." They both have front wheels that steer.

As for your theory of sway, motorcycles can be extremely stable and they only have two wheels. I'm also going to disagree with Mark Doane. The flex of tire sidewall can be important for vehicle handling on corners, but when it comes to travel trailers, properly balanced and aligned running gear is far more important.

A properly aligned, balanced and loaded single-axle trailer correctly hitched can certainly pull (and track) better than a poorly aligned, unbalanced and improperly loaded and/or hitched dual axle trailer. Dual axles are more forgiving because of the additional friction between the road and the tire. Try this. Take a roller skate. With only two wheels on the ground, roll it in an "S" path. It moves back and forth pretty easily. Now follow the same path with all four wheels on the ground.

Most vehicles have all kinds of improvements that trailers don't have, like independent front (and rear) suspensions. If you want some insight into why trailers sway, I'll let you take a spin in our '66 Dodge D200 with single beam axle front suspension.

Here's the thing. What you see on the road today, trailers and vehicles, represents the cumulative experience of billions of miles traveled and the thoughts of some of the finest engineering minds the world... and a heckuva lots of compromising to make things affordable. I appreciate the brainstorming, but there's some common sense reasons why travel trailer have the current hitch/ball setup with tires that don't steer. Again, try a practical experience. Put your kid in a little red wagon and pull him (or her) over a rough surface. Because the wagon wheels can turn, they do (even if you are trying real hard). When the wheels turn, the wagon's momentum shifts and you have real sway on your hands.

Now, if you made a travel trailer with eight or ten axles, it probably wouldnt sway much (particularly if everything was aligned), but I wouldn't want to turn it often.
hampstead38 is offline   Reply With Quote
Old 04-07-2010, 11:18 PM   #52
3 Rivet Member
 
2009 25' SS International
Pasadena , California
Join Date: Jul 2009
Posts: 147
Great idea, go right ahead... I can't believe not one trailer manufacturer has thought about this...
__________________
flmgrip is offline   Reply With Quote
Old 04-07-2010, 11:43 PM   #53
Rivet Master
 
ROBERTSUNRUS's Avatar

 
2005 25' Safari
Salem , Oregon
Join Date: Mar 2006
Posts: 7,271
Images: 18
Blog Entries: 51
Hi, I do not recommend this or suggest doing it, but I think you would be much better off installing a water tank on the front bumper of your tow vehicle for the added weight needed to keep the front wheels on the ground. This is still crazy, but to me, makes a lot more sense than your idea of weight in the rear of the trailer.

Note: I would never do this, but this thread needs someone to stir the pot.
__________________
Bob

2005 Safari 25-B
"Le Petit Chateau Argent"
[ Small Silver Castle ]
2000 Navigator / 2014 F-150 Eco-Boost / Equal-i-zer / P-3
YAMAHA 2400 / AIR #12144
ROBERTSUNRUS is online now   Reply With Quote
Old 04-08-2010, 12:35 AM   #54
Rivet Master
 
Foiled Again's Avatar
 
2012 25' FB Eddie Bauer
Vintage Kin Owner
Virginia Beach , Virginia
Join Date: Sep 2004
Posts: 5,883
Odd no one mentioned fifth wheels or the Draw tite hitch that basically puts the pivot point under the tow vehicle's rear axle.

Just wanted to toss a bit of petrol on the fire.

Paula
__________________
Today is a gift, that's why they call it the present.
Foiled Again is offline   Reply With Quote
Old 04-08-2010, 12:41 AM   #55
3 Rivet Member
 
1971 25' Caravanner
scappoose , Oregon
Join Date: Oct 2007
Posts: 197
Back on page two, (I think), of this thread, Jammer hit the nail on the head, with just three words; "moment of inertia". This concerns yaw around the polar axis, and the stability is enhanced when the moments are asemmetrical in relation to the trailer axle(s).
__________________
rangebowdrie is offline   Reply With Quote
Old 04-08-2010, 01:19 AM   #56
Maniacal Engineer
 
barts's Avatar
 
1971 25' Tradewind
Menlo Park , California
Join Date: Jan 2010
Posts: 1,223
Images: 1
Blog Entries: 4
Here's an interesting link; I took several classes during graduate school from the author, and was the teaching assistant one spring in his class in vehicle stability back in the 80s.... Equation 5.44 on page 95 is relevant...

- Bart
__________________

__________________
Bart Smaalders
Menlo Park, CA
http://tinpickle.blogspot.com
http://smaalders.net/barts
barts is offline   Reply With Quote
Reply


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
First dog in AS - how do you eliminate that dog smell? Whirlaway The Pet Forum 42 03-22-2010 06:54 PM
Greetings from VA - Connectivity issue lluquis Member Introductions 11 11-17-2007 10:42 AM
Eliminate black water tank? macman Waste Systems, Tanks & Totes 17 07-02-2006 10:47 AM
Voltage Issue Rayk Mechanics Corner - Engines, Transmission & More... 2 07-06-2004 11:38 AM
Water Issue Alex Fresh Water Systems 11 04-20-2004 05:23 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 12:16 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.