Reply
 
Thread Tools Search this Thread Display Modes
 
Old 01-03-2012, 06:26 PM   #57
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,400
Images: 5
Quote:
Originally Posted by redwoodguy View Post
Dozn---
Interesting observations for sure. I wonder if I am understanding the question correctly?

Q1: One question relates to ride harshness. e.g. the jolts and bumps felt inside the vehicle as you go over potholes or bumps or cracks in the road. I often read posts of people saying their rivets are getting jolted loose and so on from this harshness of ride.

Q2: Another question is about the frame or chassis damage - of either the TV or trailer - being damaged due to the action of the bars when driving over dips/humps which cause a lot vertical travel (compression or expansion) of the suspension in the TV or trailer.

For Q1, I don't really see how the bars can increase or decrease ride harshness in the TV. I think the ride is solely a function of the suspension of the rear TV axle and the trailer axle. The bars would affect (reduce) porpoising on wavy roads, but I don't think the bars affect jarring jolts or bumps from potholes and the like. The trailer suspension is dominant in that mode.

For Q2, it's a bit the opposite. I can easily see that there is going to be a big effect on TV suspension with very stiff bars. If you imagine bars getting so stiff they become effectively a solid link between the TV and trailer, then the TV suspension is going to have to do all the work (vertical travel) as you move this "stiffened rig" over a dip or bump. e.g. the trailer will hold the back of the TV up as you cross a dip, and the TV rear wheels will have to drop down to meet the road. Whether this is harmful to the TV, I don't know.

Q1- I concur. I think spring bars have no effect on "harshness" as you describe it. I say that because, regardless of hitch brand and bar rating you are putting x amount of force between the ball and coupler to distribute x amount of weight with any properly set up hitch configuration. Shocks are going to be transmitted through the solid coupling of the ball and trailer coupler regardless of spring flexibility. I think rivet popping etc. is more a function of TV suspension (over trucked) and/or AS axle condition, and/or TV and AS running gear balance.

Q2- This is where stiff bars hurt the AS IMHO. Could show up as bend a frame, cracked skins, broken rivets in the area of stress (front panels) and separation.
__________________

__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g is online now   Reply With Quote
Old 01-03-2012, 06:45 PM   #58
Rivet Master
 
Gene's Avatar
 
2008 25' Safari FB SE
Grand Junction , Colorado
Join Date: Sep 2007
Posts: 10,840
Quote:
Originally Posted by dznf0g View Post
I think rivet popping etc. is more a function of TV suspension (over trucked) and/or AS axle condition, and/or TV and AS running gear balance.

Q2- This is where stiff bars hurt the AS IMHO. Could show up as bend a frame, cracked skins, broken rivets in the area of stress (front panels) and separation.
Popped rivets may not indicate any of those things. In our trailer there is a line of rivets running front to back over the kitchen and door entry. They are about 2' from the curbside wall.

Most popped in the first 2 years. When I went to replace them it appeared they attached to nothing and were installed improperly at the factory. Some had to be replaced with slightly larger ones or they would fall out immediately, some didn't. Once replaced, all have stayed in place. This appears to prove poor workmanship and nothing else.

Gene
__________________

__________________
Gene is offline   Reply With Quote
Old 01-03-2012, 06:59 PM   #59
Rivet Master
 
2010 25' FB Flying Cloud
Davenport , Iowa
Join Date: Sep 2007
Posts: 1,455
Blog Entries: 1
it was so long I had to trade it . it was actually a 98, 30 foot.

and it had to be a lawyer that caught it
__________________
Airtandem is offline   Reply With Quote
Old 01-03-2012, 07:04 PM   #60
4 Rivet Member
 
2012 25' Flying Cloud
Eureka , California
Join Date: Sep 2011
Posts: 321
Quote:
Originally Posted by CrawfordGene View Post
The question of overhitching has been discussed endlessly. The easy answer is that is must because it seems so—heavier bars means a inflexible, harsh ride. A simple statement like that reminds me of conventional wisdom, however, it may be true.


Gene
I'd like to play Devil's Advocate here and challenge the conventional wisdom. I really don't see by what physical mechanism the ride can get harsher in the trailer.

In the Beginning - A Simple Hitch
If you start with no WD, and just a simple coupler and ball connection, the ride at the trailer is determined solely by the suspension of the TV rear axle, and the suspension of the trailer axle. The hitch is solid and contributes nothing to the ride by its own actions. The connection articulates freely. When there are waves in the road that cause the TV body to porpoise, it will transmit an opposite phase porpoise to the trailer, but that's not ride harshness, it is just body movement.

Adding WD Bars
The lifting action of WD is caused by connecting stiff bars from TV to the A-frame, and that now adds resistance to the movement of the ball/coupler connection. It no longer articulates freely, especially in the vertical axis. In order to articulate vertically, the bars must bend, and or the TV suspension must compress - usually both. From a ride harshness standpoint nothing has really changed. The TV suspension and trailer suspension will still determine what jolts are felt from the road into the body of either.

Adding WD bars hasn't changed the ride smoothness one bit. It only changes what happens with waves in the road. Now when you go over waves the TV body will not porpoise as much because it now has the added stiffness of the trailer coupled by stiff WD bars. The suspension in the TV will compress more because the rear of the TV body is being held down by the trailer. The TV body will porpoise less, and therefore the trailer will porpoise less. But that doesn't affect ride harshness.

A Thought Experiment
So, suppose we imagine two rigs. The first is a rig with just a ball and coupler. That represents the softest bar possible - no bar. The second has really, really stiff WD bars. Call them solid they are so stiff. Now, drive each rig over a straight path with say wooden strips every few feet. Sit inside the trailer as you drive over the strips. What difference would be experienced? I say none. The ride harshness/softness experienced is going to be controlled only by the suspension of the trailer axle, not the hitch.

I can see lots of ways and reasons that "harsh ride" could become connected to stiff WD bars, but many of those might not be causal, but rather coincidental.

Just a thought.
__________________
redwoodguy is offline   Reply With Quote
Old 01-03-2012, 07:09 PM   #61
Rivet Master
 
Gene's Avatar
 
2008 25' Safari FB SE
Grand Junction , Colorado
Join Date: Sep 2007
Posts: 10,840
Quote:
Originally Posted by Airtandem View Post
it was so long I had to trade it . it was actually a 98, 30 foot.

and it had to be a lawyer that caught it
I think I can sue you for misfeasance, misinformation, misappropriation and malapropism. Or just settle now and send me 20 grand.

Air', being in Iowa, shouldn't you be at a caucus tonight?

Gene
__________________
Gene is offline   Reply With Quote
Old 01-03-2012, 08:11 PM   #62
Rivet Master
 
Mexray's Avatar
 
1978 28' Ambassador
Morada , California
Join Date: Jan 2006
Posts: 1,583
Now, this guy walks into a bar with a hitch head with a greasy ball…

Barkeep, I'll have a Gin & Tonic, and an Airtinni for my friend here
__________________
Ray & Pat; Morada, CA
Mexray is offline   Reply With Quote
Old 01-03-2012, 08:18 PM   #63
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,400
Images: 5
Red, If I understand your statements, isn't that what I said in post #57, Q1?
__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g is online now   Reply With Quote
Old 01-03-2012, 08:22 PM   #64
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,400
Images: 5
Quote:
Originally Posted by CrawfordGene View Post
Popped rivets may not indicate any of those things. In our trailer there is a line of rivets running front to back over the kitchen and door entry. They are about 2' from the curbside wall.

Most popped in the first 2 years. When I went to replace them it appeared they attached to nothing and were installed improperly at the factory. Some had to be replaced with slightly larger ones or they would fall out immediately, some didn't. Once replaced, all have stayed in place. This appears to prove poor workmanship and nothing else.

Gene
Gene, In my scenario, I would only expect to see popped rivets in the front end of the trailer from over trucking (ie.the 3 front lower sections. This is only from my visualizing the stresses involved and forces transmitted, and is just my opinion. I am having trouble visualizing your description of where yours popped.
__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g is online now   Reply With Quote
Old 01-03-2012, 08:26 PM   #65
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,400
Images: 5
Quote:
Originally Posted by redwoodguy View Post
I'd like to play Devil's Advocate here and challenge the conventional wisdom. I really don't see by what physical mechanism the ride can get harsher in the trailer.

In the Beginning - A Simple Hitch
If you start with no WD, and just a simple coupler and ball connection, the ride at the trailer is determined solely by the suspension of the TV rear axle, and the suspension of the trailer axle. The hitch is solid and contributes nothing to the ride by its own actions. The connection articulates freely. When there are waves in the road that cause the TV body to porpoise, it will transmit an opposite phase porpoise to the trailer, but that's not ride harshness, it is just body movement.

Adding WD Bars
The lifting action of WD is caused by connecting stiff bars from TV to the A-frame, and that now adds resistance to the movement of the ball/coupler connection. It no longer articulates freely, especially in the vertical axis. In order to articulate vertically, the bars must bend, and or the TV suspension must compress - usually both. From a ride harshness standpoint nothing has really changed. The TV suspension and trailer suspension will still determine what jolts are felt from the road into the body of either.

Adding WD bars hasn't changed the ride smoothness one bit. It only changes what happens with waves in the road. Now when you go over waves the TV body will not porpoise as much because it now has the added stiffness of the trailer coupled by stiff WD bars. The suspension in the TV will compress more because the rear of the TV body is being held down by the trailer. The TV body will porpoise less, and therefore the trailer will porpoise less. But that doesn't affect ride harshness.

A Thought Experiment
So, suppose we imagine two rigs. The first is a rig with just a ball and coupler. That represents the softest bar possible - no bar. The second has really, really stiff WD bars. Call them solid they are so stiff. Now, drive each rig over a straight path with say wooden strips every few feet. Sit inside the trailer as you drive over the strips. What difference would be experienced? I say none. The ride harshness/softness experienced is going to be controlled only by the suspension of the trailer axle, not the hitch.

I can see lots of ways and reasons that "harsh ride" could become connected to stiff WD bars, but many of those might not be causal, but rather coincidental.

Just a thought.
HOWEVER, if the whole rig is moving in a more solid singular unit, it is logical that inputs to any axle would be felt more in a more pronounced manner than if some of that movement is were dissipated, or dampened by the spring bars....but I think we're talking molehills, not mountains here.
__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g is online now   Reply With Quote
Old 01-03-2012, 09:58 PM   #66
4 Rivet Member
 
2012 25' Flying Cloud
Eureka , California
Join Date: Sep 2011
Posts: 321
Quote:
Originally Posted by dznf0g View Post
Red, If I understand your statements, isn't that what I said in post #57, Q1?
It sure is! I don't know how I missed your post! Must have crossed or something. Yes, I agree with you completely on that. What I don't know is about such things as damage to a frame. I just don't have any experience to have seen that or know how it happens. I guess I am surprised that such a frame can be damaged. My frame seems so robust, I can't imagine it cracking from that reason. I certainly am not saying it doesn't happen - I've just been exploring how this hitch works so I could understand the issue.
Thanks!
__________________
redwoodguy is offline   Reply With Quote
Old 01-03-2012, 10:09 PM   #67
4 Rivet Member
 
2012 25' Flying Cloud
Eureka , California
Join Date: Sep 2011
Posts: 321
Quote:
Originally Posted by dznf0g View Post
HOWEVER, if the whole rig is moving in a more solid singular unit, it is logical that inputs to any axle would be felt more in a more pronounced manner than if some of that movement is were dissipated, or dampened by the spring bars....but I think we're talking molehills, not mountains here.
My current thinking: Since the coupler + ball is solid, with no compliance between them, I don't think the bars play any role at all. Soft or stiff bars, if the TV body moves up that movement will go to the trailer through the coupler + ball connection to the trailer. But the primary jolts in the trailer are a result of the trailer suspension. I go back to the thought experiment where you drive over strips of wood.

But hey, I am really a raw noob and just noodling this thing here to gain some insight. For all I know I have missed a major action in this hookup. Thanks for thinking it through with me.
__________________
redwoodguy is offline   Reply With Quote
Old 01-03-2012, 10:14 PM   #68
Rivet Master
 
dkottum's Avatar
 
2012 25' Flying Cloud
Battle Lake , Minnesota
Join Date: Jun 2009
Posts: 7,716
You should take this up with the people who use Airsafe hitches. Their experiences are quite different from what you describe.

doug k
__________________
dkottum is offline   Reply With Quote
Old 01-03-2012, 10:38 PM   #69
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,400
Images: 5
Quote:
Originally Posted by dkottum View Post
You should take this up with the people who use Airsafe hitches. Their experiences are quite different from what you describe.

doug k
Who are you addressing...and what does airsafe say? I'd like their take, I think their product is a viable alternative to trading in an "overtruck".
__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g is online now   Reply With Quote
Old 01-03-2012, 10:40 PM   #70
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,400
Images: 5
Quote:
Originally Posted by redwoodguy View Post
It sure is! I don't know how I missed your post! Must have crossed or something. Yes, I agree with you completely on that. What I don't know is about such things as damage to a frame. I just don't have any experience to have seen that or know how it happens. I guess I am surprised that such a frame can be damaged. My frame seems so robust, I can't imagine it cracking from that reason. I certainly am not saying it doesn't happen - I've just been exploring how this hitch works so I could understand the issue.
Thanks!

I've seen some, owners can't or won't say how they happened.
__________________

__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g is online now   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
Trip Report: Valley of the Gods, UT mello mike On The Road... 2 01-01-2012 09:08 PM
Trip Report: The Apache Trail, AZ mello mike On The Road... 1 12-26-2011 06:21 AM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 08:10 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.