Weight topic

Anything to do with mechanical, construction etc

Postby steve wolverton » Fri Aug 10, 2007 12:49 pm

Alphacarina wrote:Consider 200 pounds on the hitch ball which is 2 feet from the rear axle and then front wheels which are 10 feet from the front axle. That 200 pounds of downforce would translate to only 40 pounds of lift at the front tires and as the weight shifts forward under heavy braking, the difference would be even less than that - Certainly an inconsequential difference in braking performance on a 3500 pound vehicle . . . . if you could even measure it at all


Well, this is certainly above my head, but wouldn't the 200 pounds of hitch weight temporarily increase dramatically while braking? The trailer is trying to shove into the tow vehicle.

I notice a huge amount of braking difference while towing my 800 pound camper with a 3000 tow vehicle, and my camper is only 1/4 of my tow vehicles weight.

asianflava wrote:Even if you build your trailer heavy, there is still a possibility that you may have to shift cargo to get better balance.

I load all of my gear into the back of my camper as most of the weight is on my tongue from the TV, AC, and bathroom. My tongue weight varies from 100-150 depending on how I load the camper.
�veni, vidi, vici.�
User avatar
steve wolverton
1000 Club
1000 Club
 
Posts: 1676
Images: 11
Joined: Sun Nov 07, 2004 9:39 pm
Location: Brazoria, TX

Postby brian_bp » Fri Aug 10, 2007 4:34 pm

Two notes about tongue weight versus braking...

Load Shift
If the centre of mass (center of gravity, whatever) of your trailer is, say, two feet above the ground, and the hitch is, say, eight feet from the axle, then braking at one G (a really hard stop for a tug/trailer rig) would push down on the hitch by one quarter (two feet divided by eight feet) of the trailer weight... that's probably double the normal tongue weight, so yes, it's a big change. It's also a quick explanation, so I might have missed something (Andrew?) It's a lever thing, if you want to understand how that works...

Horizontal Force
If the trailer doesn't have brakes, then it is being slowed down by the tug, meaning horizontal force pushing back on it (forward on the tug) through the ball. Again at one G, that's the entire weight of the trailer, regardless of the tongue weight... the trailer certainly is trying to shove into the tow vehicle.

Less severe stop means lower forces... but we're talking about meaningful effects here.
Last edited by brian_bp on Fri Aug 10, 2007 4:43 pm, edited 1 time in total.
brian_bp
1000 Club
1000 Club
 
Posts: 1355
Images: 9
Joined: Sun Nov 19, 2006 1:25 pm
Location: Alberta

Postby steve wolverton » Fri Aug 10, 2007 4:40 pm

:? Gaaaaaaaah!

I like cheese.
�veni, vidi, vici.�
User avatar
steve wolverton
1000 Club
1000 Club
 
Posts: 1676
Images: 11
Joined: Sun Nov 07, 2004 9:39 pm
Location: Brazoria, TX
Top

Postby Alphacarina » Fri Aug 10, 2007 8:32 pm

Yes, but your Subie would drive much different with 1500 pounds behind it than it does with only 1,000, and logic says that every pound above 1,000 would have a negative impact . . . . and conversely, every pound under 1,000 would be a benefit

Some of us are pulling tears with small 4 cylinder cars which really aren't rated to tow ANYTHING so every extra pound is a concern

If I had a truck or a V-8 station wagon, I would be living in a full sized camper trailer, with a kitchen, toliet and standing headroom, but when you're going 70 down the pike in a 135 HP car which usually gets 30+ MPG, adding 1200 pounds is much different from adding only 1000 pounds

I consider weight a VERY important consideration - One of the recommendations for a car to get better gas mileage is simply to clean out the trunk ;)

Don
User avatar
Alphacarina
500 Club
 
Posts: 826
Images: 4
Joined: Tue Jun 19, 2007 3:26 pm
Location: Ocean Springs MS
Top

Postby Micro469 » Fri Aug 10, 2007 8:42 pm

Alphacarina wrote:Yes, but your Subie would drive much different with 1500 pounds behind it than it does with only 1,000, and logic says that every pound above 1,000 would have a negative impact . . . . and conversely, every pound under 1,000 would be a benefit

Some of us are pulling tears with small 4 cylinder cars which really aren't rated to tow ANYTHING so every extra pound is a concern

If I had a truck or a V-8 station wagon, I would be living in a full sized camper trailer, with a kitchen, toliet and standing headroom, but when you're going 70 down the pike in a 135 HP car which usually gets 30+ MPG, adding 1200 pounds is much different from adding only 1000 pounds

I consider weight a VERY important consideration - One of the recommendations for a car to get better gas mileage is simply to clean out the trunk ;)

Don


I even saw one article that said if you really want to save gas to go on a diet....... :lol:
John
Image
User avatar
Micro469
Super Lifetime Member
 
Posts: 3185
Images: 382
Joined: Mon Nov 07, 2005 10:46 pm
Location: Brampton,Ontario,Canada
Top

Postby Oak » Fri Aug 10, 2007 8:49 pm

Wow, sorry it took so long to reply. After reading all of your replies it has become much clearer.
In response to tongue weight; what if I get it all built and it turns out the tongue weight is too heavy? Will a simple shift in the position of the axle fix the problem? Or will I be s.o.l. and have to tear it all down and start over?
I might have made it out to seem that I'm building a super monster 5000lb. trailer. Not the case. It will be well endowed, but light on it's feet. Kinda like a trusty steed.
I do plan on traveling out west so yes I will have to be able to travel uphill with ease. So I will put on brakes on the trailer, just as an all around safeguard.
And as long as I take into consideration that I must keep the trailer weight lower than the trailers weight rating, I should be o.k.? And if I build heavier, I should replace the springs with the proper ones?
Like I said this won't be a tank, so the brakes and keeping the tongue weight into consideration should afford me no problems. Does that sound cool?
I am driving a 4 cylinder right now and will probably be using it for the tow vehicle.
I'm sorry I may sound so uneducated about all of this. I am just new to it all and need all the help I can get, even though my questions may not be worded right or make any sense at all. I just hope you all can bear with me.
Thanks so much!!
It may be well doubted whether human ingenuity can construct an enigma...which human ingenuity may not, by proper application, resolve." - Edgar Allen Poe
User avatar
Oak
Teardrop Inspector
 
Posts: 16
Joined: Thu Jul 19, 2007 12:12 pm
Location: Greensburg, IN
Top

Postby asianflava » Fri Aug 10, 2007 8:58 pm

Oak wrote:In response to tongue weight; what if I get it all built and it turns out the tongue weight is too heavy? Will a simple shift in the position of the axle fix the problem? Or will I be s.o.l. and have to tear it all down and start over?


Yes, moving the axle would solve about 90% of the problem. You can still get a light/heavy tongue if improperly loaded. Wether or not moving the axle would require a total rebuild depends on how the trailer was built.
User avatar
asianflava
8000 Club
8000 Club
 
Posts: 8412
Images: 45
Joined: Mon Aug 02, 2004 5:11 am
Location: CO, Longmont
Top

Postby Oak » Fri Aug 10, 2007 9:10 pm

I plan on building on a HF. Not sure which size yet. I am still working on that.
It may be well doubted whether human ingenuity can construct an enigma...which human ingenuity may not, by proper application, resolve." - Edgar Allen Poe
User avatar
Oak
Teardrop Inspector
 
Posts: 16
Joined: Thu Jul 19, 2007 12:12 pm
Location: Greensburg, IN
Top

Postby ninerhb » Fri Aug 10, 2007 9:45 pm

Oak wrote:I plan on building on a HF. Not sure which size yet. I am still working on that.


That's where the "how it's built" can matter. A 4x8' teardrop on that trailer and moving the axle is easy - just unbolt it and move back, or reweld, or whatever. The problem is if you try to build a 5x8 or 5x10' teardrop on that 4x8 HF trailer - if you need to move your wheels, you need to move your wheel wells, and that can require some extensive modifications.

Henry
ninerhb
Teardrop Inspector
 
Posts: 19
Joined: Thu Jul 19, 2007 11:13 pm
Location: Lansing MI
Top

Postby Oak » Fri Aug 10, 2007 11:39 pm

That's the deal. I plan on building a 5x8 on a 4x8 frame unless I can find a 5x8 frame for around the same price. I have yet to find a 5x8 that doesn't have side rails or doesn't cost 700-800 dollars.
I guess I'm in for somethings I didn't expect...
It may be well doubted whether human ingenuity can construct an enigma...which human ingenuity may not, by proper application, resolve." - Edgar Allen Poe
User avatar
Oak
Teardrop Inspector
 
Posts: 16
Joined: Thu Jul 19, 2007 12:12 pm
Location: Greensburg, IN
Top

Postby Esteban » Sat Aug 11, 2007 12:42 am

Oak, If you will be adding brakes to a HF trailer it will probably be a costly upgrade. You also want to build a 5x8 on a 4x8 HF trailer. It seems to me that you're beginning to to cross over to a where a custom trailer frame may be a better value for you. I just bought a Dexter Torflex #9 axle with brakes which added about $130 to the cost. To add brakes to a HF trailer you might have to throw away it's axle and start over with a new axle and brakes. By that time you're lost the cost advantage of the HF trailer and you still have to customize your cabin to fit over it.
Steve - SLO, CA
Esteban
Donating Member
 
Posts: 1684
Images: 15
Joined: Fri Jul 28, 2006 4:39 pm
Location: California, San Luis Obispo
Top

Postby Muggnz » Sat Aug 11, 2007 5:19 am

Does the height of the hitch matter?

Especially on a light weight car, such as my Corolla?

tia
User avatar
Muggnz
Crybaby
 
Posts: 600
Images: 34
Joined: Sat Apr 28, 2007 5:12 am
Location: Karori, Wellington New Zealand
Top

trailer

Postby donkro » Sat Aug 11, 2007 8:34 am

Oak , go to Redtrailers.com, you can buy a 5X8 utility trailer for less than $500. I bought the folding black one and there's info on this forum that will tell you how to make it non folding. They do sell a nonfolding 5X8 for more money but it also weighs about 75lbs more.
donkro
Teardrop Builder
 
Posts: 49
Joined: Mon Jan 15, 2007 11:24 pm
Location: Chicago
Top

Previous

Return to Teardrop Construction Tips & Techniques

Who is online

Users browsing this forum: No registered users and 6 guests