Recently I stated that Sundowner used two hinges on each of its rear doors, whilst most other manufacturers used three or even four. In a rebutal, a representative of Sundowner made the following statements:

"The reason Sundowner only has two hinges per door is because strap hinges are a weaker design than the one Sundowner uses. So you need 4 or 5 strap hinges to do the same job of just two Sundowner hinges. Actually two of the Sundowner hinges work better than the 4 or 5 strap hinges with the force of a kicking horse"

"When a horse kicked a trailer with rear doors with strap hinges it knocked the door out of align "

Based on my ownership of two different trailers equipped with strap hinges, I became curious to see if I were the only one not to experience any difficulties with bolt on hinges. I spent a few hours contacting various trailer owners I know, and came up with the following representations. Sidekick (1), Exiss (3), Sooner (2), 4Star (2) Kiefer (1) Logan (1) and Featherlite (3) 

They resulted in 13 trailers, 26 doors and 90 bolt on strap hinges. The trailer ages were 1996 to 2010. None of my acquaintances currently own SD equippment. Not one trailer owner, including me, ever had a hinge problem that resulted in a door either sagging or being out of alignment. The most common issue was proper hinge lubrication for the older trailers. The doors' operation became stiff when proper maintenance wasn't observed.

In addition, three of the owners I questioned, had trailers that featured welded hinges instead of the strap type. These trailer brands were Elite (1), Hart (1), and a Cimarron (1). These brands became most interesting, particularly in light of the SD representative's statement, with SD only using two hinges because of their superiority. 

 The Elite had 4 welded hinges per door; the Hart had 4 welded hinges, and the Cimarron had 5 welded hinges per door. None of them had any hinge difficulties or sagging doors, but then you wouldn't expect them to with a least double the number of hinges.

All told, in the lot were sixteen trailers, twenty nine doors, one hundred sixteen hinges and no failures. I realize these number are too low to make an "official" survey. But based on their results, I find that strap hinges are just as reliable as welded. They also have the advantage of being easily replaced, if ever they are damaged.

My original statement alluding to more hinges being better than two, seems to be born out by the construction methods used by most of the major brands of trailers.

Just my $.02

The problem is not with sagging on the strap hinge.  The problem I had was when the door took a direct blow from a horse the door bulged out 3/4" from the door frame.  The Strap hinges bent out. Not down.

Rick

Sundowner of Aiken

I haven't tried to prove anything. I was asked to point out differences among the trailers, which I did. Many aluminum SDs are out there and have been around for years. This proves their design works.

What I described was a two point door suspension, that offers little strength where the horse's butt will strike it. I personally watched a SD door being bent in the middle, when an errant horse backed into it, when a butt strap wasn't attached. The fact that SD stands pretty much alone in the industry with two door hinges, while everone else reinforces their doors with middle hinges, should be a clue. The Exiss brand has three hinges from the middle down, the area most impacted by a horse. In addition it has a fourth at the top.

When I started the thread about the details, I said that I wasn't interested in initiating a flame among the various trailer brands. You asked for differences and I gave a few. Details do matter, that was the point of my thread. It's up to you to become informed enough to make an intelligent decision. I have tried to offer constructive information, but I will not be held responsible for your final decision. I don't have to prove anything. You have to make up your own mind.

My background differs from yours. What I value in a construction, and how I use my equippment will vary from your ideals. I have chosen my purchases based on my beliefs. You have to do the same.

Guard,

On the Sundowner you observed was there a failure of either the door or hinges?

Absolutely. The door bent in the middle where it wasn't supported.

BTW. I'm not, nor have I ever been, a guard.

Gard,

Sorry about the spelling.  So the door did not bend back on it's own?

RTSmith,

Very well said thank you for the clarification. I think that will help folks understand the differences a little better.

I haven't tried to prove anything. I was asked to point out differences among the trailers, which I did. Many aluminum SDs are out there and have been around for years. This proves their design works.

What I described was a two point door suspension, that offers little strength where the horse's butt will strike it. I personally watched a SD door being bent in the middle, when an errant horse backed into it, when a butt strap wasn't attached. The fact that SD stands pretty much alone in the industry with two door hinges, while everone else reinforces their doors with middle hinges, should be a clue. The Exiss brand has three hinges from the middle down, the area most impacted by a horse. In addition it has a fourth at the top.

When I started the thread about the details, I said that I wasn't interested in initiating a flame among the various trailer brands. You asked for differences and I gave a few. Details do matter, that was the point of my thread. It's up to you to become informed enough to make an intelligent decision. I have tried to offer constructive information, but I will not be held responsible for your final decision. I don't have to prove anything. You have to make up your own mind.

My background differs from yours. What I value in a construction, and how I use my equippment will vary from your ideals. I have chosen my purchases based on my beliefs. You have to do the same.

Two years ago I and my family were at a show in OH. As my wife and I walked beside my daughter while exiting the show ring, we passed a mother and teen age daughter trying to load the second of two horses into a 3HSL SD trailer. The horse would partially enter, rear and then forcefully back out. This happened several times while we watched. The other previously loaded horse started getting edgy, and proceeded to stomp and shuffle about.

Another couple who apparently were traveling companions came to help. They brought two whips. Again the horse was led partially inside, reared and refused. This went on for several minutes as the owners lost their cool, and decided they would MAKE the horse load. When the horse again had its front end in the trailer, the other couple used their whips to force the horse forward into the stall. As soon as the rump cleared, the daughter closed and latched the right rear door.

In seconds there was an explosion of noise and movement. The horse was slamming and kicking the insides of the trailer, and especially the rear door. The cadence and ferosity increased dramatically and everyone was yelling, but not knowing what to do.

The noise suddenly stopped and the mother ran to the head side drop window. After looking inside, she screamed "he's down". There was then a discussion about what should be done. One of the companions went to the rear door to open it. Before he could, there was a loud bang and the trailer looked like it jumped off the ground. The door flexed on its hinge side. A second bang and more movement then occured. This time the whole door flexed and bent in the middle.

The motion and noise soon stopped, and once again they decided to open the door. The vertical bar attached to the latch handle was bent. The lower cam lock was jammed into the bottom casting. They could not release the door and open it. A grounds keeper had a utility vehicle, and drove it to his maintenance area to get some tools. He returned with a hand sledge and a crow bar. The lower fitting was struck until it was destroyed. This permitted the rod and the top camlock to rotate, allowing the door to open.

The horse was badly shaken, on his feet and bleeding from several areas of his legs, hip and face. He was unloaded and taken away to be inspected and cared for.

When we approached the trailer to check on the other horse, the right rear door was open, and noticeably sprung in the middle. Upon closer inspection, the bottom hinge boss was cracked from the outside surface to the hinge pin. The vertical locking bar was bent, and the lower cam lock and its receptacle were mostly destroyed by the hammering.

The horse survived, and was again being ridden, when we spoke to the owners at one of last year's shows. They were then owners of a 4Star trailer.

A few points that has yet to be mentioned, are that the bolt on hinges can be easier to adjustreplace than the weld on hinges. I have had door channels and door frames get tweeked at the hinge attachement point and bind the door. On bolt on hinges, it is easier to adjust to make the door swing freely. On weld on, you must fix the tweek or reposition by rewelding.

Also, the less number of hinges on the doors, the easier it is to manufacture. Extremely close tolerances are required in lining up 3 or more hinges to operate propperly.  Using just 2 hinges, tolerance is very forgiving and less skills/costs are needed to produce.

I have bent trailer doors with 5 hinges as well as those with 3 when exposed to enough force. I have noticed on the weld on hinges, the extruded frame is what bends/breaks, not the hinge. On bolt on, it is typically the hinge.

What is best? IMO the more hinges, the better. Call me closed minded, but I would not consider a trailer with 2 hinges on any door exposed to livestock.

Just my observations.