Removing a Leaf From HF Trailer Suspension?

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Removing a Leaf From HF Trailer Suspension?

Postby absolutsnwbrdr » Fri Aug 12, 2011 1:43 pm

I have the 1720# rated trailer, and am interested in possibly removing a leaf from the springs.

I've heard of it being done, but was wondering if anyone had a walk-through of how they did it, which leaf to remove (bottom, middle, both), and how much it affected the ride.

My entire trailer weights about 800-900lbs fully loaded.

I've already lowered the tire pressure to around 20psi.

Thanks!
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Postby bobhenry » Fri Aug 12, 2011 1:55 pm

FYI

Duro tire ( that's what came with my HF frame ) will not cover any warranty claims on underinflated tire.

I know! I got into a heated discussion with them when one of mine went corkscrewy with a ply seperation

Inflate to what is posted on the sidewall !

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Postby Yota Bill » Fri Aug 12, 2011 4:59 pm

The pressure that is molded into the sidewall is the max pressure the tire is rated for, and more often then not is well over what it actually should be set at. Not honoring a warrenty for having it set less then max is just a scare tactic to get out of replacing the tire at thier expense.
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Postby 48Rob » Fri Aug 12, 2011 7:15 pm

Zach,

Contact the axle/spring manufacturer.
They can tell you exactly what each leaf is rated at, and what the new rating will be when you remove (almost always) the bottom leaf.

I'm running 23 pounds on my Cabin car trailer tires.
I don't know what the spring rating is because I used a vintage axle/springs, but am guessing 3500-4000 pound rating.
The trailer weighs 2400-2600 pounds, and rides very, very well at that tire pressure.
Max pressure rating on the tires is 45psi.
Because a tire has a maximum number on it, does not mean that the tires must always be inflated to that number...

I "de-rated" the springs on a cargo trailer for a friend a couple years ago.
Using info from the manufacturer, I removed the bottom leaf to get the spring rating closer to the actual weight of the loaded trailer.
The job wasn't too hard, and made a big difference in the ride of his trailer.
We also adjusted the air pressure in the tires, always very important to match the tire pressure to the weight being carried if you want/expect the smoothest ride possible.

Here is a link to how it was done;
http://48rob.yuku.com/topic/21
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Postby angib » Sat Aug 13, 2011 10:36 am

48Rob wrote:Because a tire has a maximum number on it, does not mean that the tires must always be inflated to that number...

Yep, it's curious how come folks always say that trailer tyres must be inflated to the maximum but Ford and GM never say that for their vehicles....

I think one influence is trailer manufacturers that specify the very smallest tyre that will do the job, so those need to be run at their maximum pressure to get the full capacity.

A decent rule of thumb for over-sized tyres is that they can easily handle the same percentage of the maximum capacity as the percentage of the pressure. Hmmm, that doesn't read easily, does it? :thinking:

An example: a tyre inflated to 3/4 of its maximum pressure is happy carrying 3/4 of its maximum capacity - it will actually do more, but 3/4 for 3/4 is easy to remember.
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Postby absolutsnwbrdr » Sat Aug 13, 2011 11:23 am

Thanks guys!

Bob thanks for your concerns. Running a tire with lower than max pressure is normal though. My car tires are rated for max 45psi. I run 32 in the front and 30 in the rear. The air pressure required is based on the weight of the specific vehicle. My same car tires may need lower inflation on a lighter vehicle (as specified by the vehicle manufacturer.

Lower pressure is not the same thing as under-inflated though. There was a thread on here somewhere where the post described an under-inflated tire will deflect way too much over bumps and around corners, causing you to pop the bead.

The picture of your tire looks like that is a manufacturing defect, not underinflation.

Rob, that link is perfect. Doesnt look like it should be too bad of a job to do, especially on a leaf spring that isn't completely covered in rust.
Last edited by absolutsnwbrdr on Mon Aug 15, 2011 7:32 pm, edited 1 time in total.
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Postby bdosborn » Sat Aug 13, 2011 12:47 pm

Tire pressure is a function of capacity *and* speed. You need to pick a pressure that will safely carry your trailer weight and be rated for the speed you're going to travel. Goodyear *used* to have a link that would allow me to run my 65 mph Marathons at 75 mph if I added another 10 psi to the minimum pressure I needed for my load. (I can't find it anymore, they've had some issues with Marathon tires so I suppose they don't publish that anymore.) So for me, I need 45 psi:

Goodyear Load Inflation Tables

I weighed my trailer and it has a 2500# axle weight when loaded. Each tire has to carry around 1250#. The table says I need 35 psi for my ST 205/75R14 tires to support 1400# at 65 mph ( I like a little safety factor so I use 1400# in case I weigh the trailer down with more stuff). I can pull it at 75 mph if I add 10 psi so I run my tires at 45 psi, which is only 5 psi less than maximum tire pressure. Max inflation for me wouldn't be overdoing it by any measure. Luckily I have a torsion axle so the trailer still rides great.

I've never found the same type of table for a HF tire, but be aware they are only rated at 45 mph. :rainy: Granted, my trailer is about twice as heavy as a teardrop but I would think about it before I lowered my tire pressure a bunch. From the Goodyear website:

"IMPORTANT: It's a common practice for RV owners to lower tire pressure in their search for a smoother ride. This is not only dangerous, it's relatively ineffective, as the difference in ride quality is not significant. When minimum inflation pressure requirements are not met, tire durability and optimum operating conditions are compromised. Tire inflation pressure should always meet at least the minimum guidelines for vehicle weight."


Bruce

P.S. I don't think I've ever read about a HF tire blow out, so maybe the whole issue is moot given how light teardrops are? What is the load rating and max pressure for a HF tire? Somebody needs to do the math so we can develop a load rating table...
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Postby bdosborn » Sat Aug 13, 2011 3:27 pm

Here's a chart I did showing capacity versus inflation pressure based on the HF Trailer tire:

12" HF Trailer Tire

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This based on a straight percentage of pressure versus capacity -

capacity # = psi/80 psi*1045#

As angib points out, this is pretty conservative, the actual capacity is probably more than what the straight percentage yields.

The max speed has gone up from the tires I had on the tear, its now 55 MPH.

40 psi would work for a 1000# trailer that's well balanced side-to-side. I'd add 10 psi if you plan on going faster than 55.

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Postby bobhenry » Mon Aug 15, 2011 11:50 am

We are talking apples and oranges I assumed we were talking "Trailer tires" not automotive.

Here is what the folks at Carlisle say about TRAILER tires.

Please read to the end

http://www.title-3.com/Tires.htm
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Postby bobhenry » Mon Aug 15, 2011 11:57 am

In case ya didn't make it to the end........

Basic Rules

Always inflate the tires to the pressure indicated on the sidewall, check it every day of towing.
Tow the trailer level when both the tow vehicle and trailer are loaded for camping.
Don't overload the trailer axle. This requires knowing the axle rating and weighing the trailer.
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Postby len19070 » Mon Aug 15, 2011 2:45 pm

Zach...Ya ever find out how to remove the spring?

Happy Trails

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Postby absolutsnwbrdr » Mon Aug 15, 2011 4:32 pm

len19070 wrote:Zach...Ya ever find out how to remove the spring?

Happy Trails

Len


:thinking:

Its here somewhere. I think I have to deflate the tires first.
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Postby legojenn » Mon Aug 15, 2011 6:02 pm

absolutsnwbrdr wrote:
len19070 wrote:Zach...Ya ever find out how to remove the spring?

Happy Trails

Len


:thinking:

Its here somewhere. I think I have to deflate the tires first.


Where's the 'like' button?
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Postby len19070 » Mon Aug 15, 2011 7:26 pm

absolutsnwbrdr wrote:
len19070 wrote:Zach...Ya ever find out how to remove the spring?

Happy Trails

Len


:thinking:

Its here somewhere. I think I have to deflate the tires first.



Rob's link is pretty complete.

http://48rob.yuku.com/topic/21

Happy Trails

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Postby bobhenry » Tue Aug 16, 2011 1:19 pm

absolutsnwbrdr wrote:
len19070 wrote:Zach...Ya ever find out how to remove the spring?

Happy Trails

Len


:thinking:

Its here somewhere. I think I have to deflate the tires first.


The initial post also mentioned underinfalted trailer tires so I was NOT off topic. Sorry I bothered to broaden the post to its full scope.
I will try and just follow the bold print heading in the future. :(
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