Re Towing A frame on box Trailer

[rod]

Hi I am newbie to the forum. I am trying to weld up my first box trailer.The Trailer I am making is 7ft x 4 ft single axle.
I have a few of questions. Does it matter how long the A frame is for towing ? if not , What would be an ideal length? Where should I set up the axle ,should it be centre of the trailer or should it be of centre ?
Thanks In Advance

[SkidSteerSteve]

By A frame, I'm guessing you are refering to the tounge. I don't know if you can (within reason) have one too long, but you can get them too short. If I'm doing a custome trailer for something, I measure the width of the vehicle that I'm pulling it with and make sure the "ball-to-trailer" length is at least equal to half that. That way you can turn the trailer sharp and not worry about jack-kniving the front corner of the trailer into the tow vehicle. As far as the axle placement, the rule of thumb for general use trailers is to put the axle centerline at 60% of the total length back from the front of the trailer, not including tounge (7ft = appr 50"). That will usually give you a good balance when pulling without overloading your hitch. If it is going to be a dedicated use trailer, then you will need to weigh your equipment and lay it out accordingly to what your frame and hitch will handle. SSS

[rod]

RE:RE A tow frame

Thanks Skidsteersteve,Yes I am talking about the Tounge of the trailer.Thanks for the info.I am not goint to go overboard with it I just wanted to go, maybe another 1ft longer than the norm.Most of the trailers I have seen the tounge has been just short of 6ft so maybe 7 ft or a smigin longer.

By A frame, I'm guessing you are refering to the tounge. I don't know if you can (within reason) have one too long, but you can get them too short. If I'm doing a custome trailer for something, I measure the width of the vehicle that I'm pulling it with and make sure the "ball-to-trailer" length is at least equal to half that. That way you can turn the trailer sharp and not worry about jack-kniving the front corner of the trailer into the tow vehicle. As far as the axle placement, the rule of thumb for general use trailers is to put the axle centerline at 60% of the total length back from the front of the trailer, not including tounge (7ft = appr 50"). That will usually give you a good balance when pulling without overloading your hitch. If it is going to be a dedicated use trailer, then you will need to weigh your equipment and lay it out accordingly to what your frame and hitch will handle. SSS

[harcosparky]

We are also building a trailer, and yeah I dont think they can be too long. ( well I guess they could be, thinking on it a bit ) However all my reading says a tongue should be a " minimum lentgh of 3 feet, ( 36" ). Some have said 3 1/2" ( 42" ) on various forums. Keep in mind what it will be towed behind. Drive out to a trailer dealer and measure how long they are on models similar to what you are building.

On small lightweight trailer ( Class I I imagine ) I have seen tongue made of just a single straight piece of square boxed tubing - not that I would make mine like that. What you are concerned about is manueverability of the trailer behined the tow vehicle.

[Danny]

For a reference, look at how nice the average boat trailer backs up, and then think about how the average snowmobile trailer or utility trailer backs up. Your trailer is kinda short so if the axle is set at 60% back like mentioned earlier you may want to run a little longer then average tongue, the distance from the ball hook up to the axle is what makes a trailer back up nice, the axle location in relationship to the load carrying part of the trailer has the big effect on how it goes down the road, (along with loading the trailer properly). This is what I believe, but it is certainly open to criticism, other may have other theories?

[SkidSteerSteve]

I agree on the longer the better when it comes to small trailers. I have trailers from four foot to over twenty. The smaller ones I rarely pull with the Dodge, because you just about can't back them in anything outside of a straight line. That's when the little Ranger is so handy. It'll back anything. I have a little twelve foot flatbed that I stretched the tounge out on it about an extra foot. That lets me drop the tailgate and still have room to get stuff in and out of the truck rather easily. Along those lines, I usually build a separte bracket to mount my jacks on and not use the hole punched in most couplers. This is so that I know I'll be able to drop the tailgate and not hit the top of the jack. SSS

[harcosparky]

Well I did a tiny bit of research .... and this is what the State of California has to say....

The tongue length on the trailer is generally twice the trailer wheel width but no more than six feet from the axle to the end of the tongue. Good design will allow for good sway control. If the tongue is too short, the trailer will sway. If too long, the trailer will be sluggish and cut corners when turning.

Here is a URL from them .... http://www.dmv.ca.gov/pubs/dl648/dl648pt12.htm They cover a lot to consider for SAFE trailering.

I assume they speak of length here as " overall length " of the tounge assembly to include the portion UNDER the trailer box. How much is in front of the box I can't tell from this.

But it is an interesting read on trailering. I have towed trailers since I was 18 and in the Army some 32 years ago. I can tell you backing a trailer has more to do with experience and training, than it does with tongue length.

Try backing a trailer that is one fourth the length of the vehicle towing it UP a ramp and into the belly of a USAF C-141. You learn reall fast how to back a trailer up correctly the first time, or they don't let you do the loading.

Gee .... I never realized how much life in the army has taught me! LOL