Weight on the hitch observations?

[regis101]

Hello. I don't know how to properly title this thread.

I'm curious about how the tongue weight from a given trailer acts as compared to having a bike rack with four bikes hanging off the back.

An example would be if a 180 lb person was to put their 2" ball mount into the hitch and stand on it, would this simulate tongue weight?

Then if a bike rack was inserted with four bikes hanging off and the hitch has more deflection what does this tell me.

The bike rack and bikes weighs less than the 180 lb man. But it makes the hitch flex.

Does the weight compound as it cantilevers away from the attachment point.

I'll stop. Getting cornfused. Any help?

[S. Heisley]

Hi, Regis:

Maybe these will give you the answers you’re looking for:

Look here: http://www.angib.pwp.blueyonder.co.uk/t ... tear81.htm for trailer balance

And here: http://www.angib.pwp.blueyonder.co.uk/t ... tear84.htm for tongue strength.


If you have problems looking, click on the Design Library at the top of your screen and look for the picture of the broken tongue on the right. The other one is just above it. Hopefully, these will help.

[Arne]

The 180 sticking out will cause more deflection than the same weight on the ball... because it has leverage.

180# tongue weight of a trailer would be the same as a man standing on the hitch.

Think about a wrench. You can't turn a tight nut by hand, but a wrench can.... leverage.

[regis101]

Great reading. I should have known there'd be info in these pages.

I feel safe that the 4 x 8 TSC open floor 1500# trailer I'm using has the proper tongue.

Also digging around for info about the strength of the hitch.

For my application, there is a manufactured hitch with a Class 1 design. It's good for 100/1000. This is about as much as I'd want to know with the 'ol VW Bus. I also don't want to actually max out the hitch weight. So I'm thinking that a 80 - 90 tongue weight is where I'll be at for a while.

This a pdf file link for the manufactured hitch

http://sitepro12.sitepro.com/masterlibr ... 55_INS.pdf

This inquiry also stems from that I can get a nice hitch that is made more for vehicle fit and not so much on tested strength. It's 2 x 2 x 1/4 angle with a 40" span. To that is either a ball mount, 1 1/4 or 2" receiver. Stout but I've had mixed reviews.

http://www.globalserve.net/%7Ejrivers/latebayhitch.htm

It's easy to say , Oh yeah, no problem. But what if.

[regis101]

Thanks for the replies. I didn't think hard enough about the leverage thing.

Tongue weight from a trailer presses basically straight down, I'm thinking.

A loaded bike rack hanging of the hitch would have more front to back almost bouncing action. Thus twisting the hitch up and down.

[bobhenry]

The safety factor built into the Drawtite hitches is 100% so a 100/1000 rated hitch will never fail until doubled 200/2000 or more !

I as an idiot hauled a double axle trailer with a utility tractor and bushhog on a class one hitch for 2 years without a problem. Had I known what I was actually doing I would have been worried to death.

[regis101]

Thanks for the tip. I'm only looking for 150/1500 max since this is what the trailer is rated for. I'm still going to keep 'er at 100/1000 tops.

[Arne]

Just a note on ball mounts. My ball mount stuck out about 2.5 inches too far. I pushed it all the way into the receiver/hitch, marked it and drilled a new pin hole. Looks much better and I don't feel the trailer bouncing as much.

I also welded one nut on the side of the receiver and one on the top of the back and on the bottom of the front... Now, with the pinch bolts tightened, there is no slop between the ball mount and the hitch... very nice not to here that clanking for thousands of towed miles.

There are commercial devices that claim to do the same thing, but do not know how good they work.

[Barefoot]

Some folx mount their bikes on the front of the tow vehicle. No complicated rear hitch combinations and no math. Some mount them on the back of the tear. No complicated mounts and just a little math.

[regis101]

I like the idea of a receiver on the back of the trailer. Easy enough to add some tube steel to the rear two cross members, I suppose. 1 1/4 is all I need.

I do have a bolt on bike rack that fits two. It's for the front bumper.
We now have four bikes to deal with. And secondly, the bikes on front take away from some headlight beam when traveling at night.

Thanks for the thought.

[Arne]

The thing about a hitch on the back of the t/d is it is usually a square tube that spans 2 x members, removing the flex that would occur on the tow, which in reality is only 1 x member. Therefore, it would not have to be very heavy duty to carry just bikes. As long as the x members are beefy enough.

[regis101]

The TSC 4 x 8 open floor trailer uses 1/8" angle. Not beefy enough for me. Having the tear on there would add some strength but I'll back up the first two x members with some thicker angle or tube steel.

[regis101]

I picked up an adjustable Class 2 hitch with 1 1/4 receiver today from an ad on craigslist.

It was easy to modify to fit our Bus. Although it's rated for 350/3500, I will never get that high using the Bus as a tow car. After shredding some metal to make it fit, the hitch weighs in at 20 lbs. The factory OE style hitch is a 100/1000 and weighs 10 lbs. It feels good to have a real hitch
back there. Reese 88001. Mine is an older version that came from a 95 Explorer. Newer models are very user friendly.

[regis101]

So now my thought turns to the ball mount. I don't want to end up with a collection of them. So if I know that the trailer is 12" to the bottom of the coupler from the ground and the hitch on the tow car is 12" from the ground, how do I pick the proper ball mount.

I will expect the rear of the vehicle to sag when hitched up. Hopefully no more than 2". Is the end result to have the trailer level when hitched up?
If a 2" sag on the tow car happens. I'd prolly want a 2" rise on the ball mount? Sounds easy enough but I'm looking for experienced tow persons.

I don't know what will happen with 100-200 lbs of TW. I just used 2" as an example.

Thanks,

[McBrew]

I would set up the ball mount at the same height as the trailer. If you have too much sag when you hook up the trailer, consider getting some spring helpers or air bags for the rear suspension on the bus.

My car only sags about 1" with 150# tongue weight, but I am adding Air Lift 1000 bags to the rear springs. I've done that on other TVs that I have used, and it always made the ride better and kept everything level (headlights aimed properly, etc).