Sport45 wrote:Cdash wrote:
If someone can measure distance center of rail to center of rail, and distance from center of pin to center of rail, I can tell you how much more is pushed either forward or back.
Will this work?
Perfect!
I am going to reference numbers off the picture using right and left (as it is shown in the picture). The rotation of the base in the truck will determine weather the loads I provide are fore or aft of the truck axle.
Here are the numbers:
For a 1,000 pound vertical load on the ball the right rail would see 708 pounds and the left rail would see 296 pounds. Or to simplify it for a known pin weight: 70.8% of the pin load to the right rail and 29.6% to the left rail.
I think fixed fifth wheel hitches would have a 50 - 50 distribution if the pin center is centered between the rails. On sliders, the distribution will probably put the majority of the weight on the front rail. I'd have to measure to get exact numbers, but my Superglide would put the majority on the front rail.
The horizontal load, which others have pointed out will exist in any type of hitch, but giving numbers just to give you a point of reference:
A 1,000 pound horizontal load on the ball applied towards the right looking at the same picture will result in 656 pounds downward force on the rear rail and 656 pounds upward force on the front rail. If you have it at the highest (18" setting) it will be 750 pounds for every 1,000 pounds.
So putting both of these together could quickly put all the vertical pin load on the rear rail, aft of the trucks rear axle. Whether that is or will be a problem, is anyone's guess. Most seem to do fine, but if not, I would think these numbers could provide some insight. To be fair, similar things will happen with a regular fifth wheel hitch, but not to the extent of an Anderson base oriented to provide maximum cab clearance. The simple way to say it is "You can't move the load further back without the load being further back".
In reality, I don't think there is any good way to ever know what the horizontal force would be. It would depend on speed, wind velocity and direction, grade of road, alignment of axles, tire inflation, etc. If I were guessing, I would expect that horizontal load to generally be around 25% of the trailer weight, but I am just completely guessing.
So in summary, the message I would like people to think about is what they are trying to accomplish. If they are using it because physical reasons favor a lightweight hitch, great. If they are using the Anderson with the ball closer to the cab, then I don't see much potential for issues. If someone has a bit too much trailer for the truck and are trying to preserve payload by having a lightweight hitch, that is fine. But by orienting that hitch to provide maximum clearance while you are close or over on weights "could" lead to having some handling issues due to how the hitch transfers load aft of the rear truck axle. Just something to consider when making your hitch decision.
And for the record, the Pullrite Superlite hitch that is similar to the Anderson, looks to have the ball centered between the front and back rails (can't find actual dimensions to verify this), so it would load the rails more similar to a conventional hitch with a 50 - 50 front/back distribution. Te two companies are providing a similar product, but have taken different paths to the final product. I would assume that each has their reasoning for what they did.
Cdash wrote:
If someone can measure distance center of rail to center of rail, and distance from center of pin to center of rail, I can tell you how much more is pushed either forward or back.
Will this work?
