Relationship between lengths of TV and TT

I spent my working life in a tractor that weighed 17,500 lbs that had an overall gross of 140,000. Our allowable weights in Canada are more liberal than in the States for our trailers. If you can comfortably pull and stop, there should be no restriction on your trailer size. The caveat being that you should have some sort of training to haul anything longer than about 25 feet to remain a safe operator on the road. Too often we see someone with deep pockets buy a big pickup and a 40 foot fifth wheel and hit the highway with no idea what to do.
Off the soapbox now........just my humble opinion.

wing_zealot wrote:
Most Semi trailers are 53-feet long, most of the tractors pulling them have a 13-feet long wheelbase (about the same as an F150 Supercrew). So in the same context a 25-feet long trailer should only need a 6.5-foot wheelbase. And actually, you have some semi tractors pulling two or even three semi trailers. My point is, There is no ratio that needs to be observed. But the longer the better it will handle.

You are right, and in addition most over the road class 8 tractors weigh about 1/3 of the fully loaded trailer weight (about 60k lbs+ trailer and load). This assuming a total GCVWR of 80,000 lbs.

GaryWT wrote:
Just read elsewhere, general suggestion, wheel base divided by 5 equals trailer length, give or take a few feet. With this said, my guess is many the pull trailers over 30 feet might not always meet this.

Based on your trailer length and is you have a full size SUV, you will most likely be good. As said earlier, the weights are most important.

The MB wheelbase is 121". Divided by 5 = 24.2' The Tracer has a 22' box and is 25' total.

Just read elsewhere, general suggestion, wheel base divided by 5 equals trailer length, give or take a few feet. With this said, my guess is many the pull trailers over 30 feet might not always meet this.

Based on your trailer length and is you have a full size SUV, you will most likely be good. As said earlier, the weights are most important.

If you keep all the With respect to towing a travel trailer, you only need plan for weights. If you can keep the tow vehicle under all its ratings, the length doesn't matter. That is, weight doesn't matter for TTs as the range of weights for any given length makes trailers that are "too long" far heavier than any modern passenger vehicle can handle.

If you want a mechanical engineer's answer to this: no, there is no simple formula or any "gospel" rule-of-thumb that applies. There are simply more variables than can be answered discretely in this day. Trailers comes in too many flavors now... The exact same trailer frame - length, axle centers to coupler, axle size and capacity and suspension all same - can be loaded very differently, which can be seen in tongue weight but tongue weight doesn't tell the whole story. The center of gravity can also be very different because one trailer has a barrel roof and the other flat; throw in a couple of air conditioners on the roof of one and only one on the other; and/or, one has a single superslide and the other maybe slides on each side. Then what's your weight distribution strategy and equipment. Just some of the variables for the trailer. Then with the tow vehicle there are so many wheelbase configurations, weights, and suspension options, all of which change the vehicles center of gravity and behavior let alone how the tow vehicle is loaded for any one trip (especially where kids are involved).

I guess I'm driving at a point that towing within ratings and using appropriate hitching equipment for the task at hand in consideration of both the trailer and tow vehicle is the fundamental for "capability." Then you can most certainly argue that the "comfort" of the tow lies in definitely having more tow vehicle than less! Dragging your 25-footer behind a 3500 DRW diesel long bed will have you checking your mirrors just to make sure a trailer is back there, but might also have you crying monthly when the loan check goes! But darn the tow is comfortable! See where I was going?

Happy camping!

I know of no authoritative physics on this issue. It makes perfect sense that the longer the TV the better it will handle a longer trailer.

Most Semi trailers are 53-feet long, most of the tractors pulling them have a 13-feet long wheelbase (about the same as an F150 Supercrew). So in the same context a 25-feet long trailer should only need a 6.5-foot wheelbase. And actually, you have some semi tractors pulling two or even three semi trailers. My point is, There is no ratio that needs to be observed. But the longer the better it will handle.

there is a rule of thumb and it is in the section above int he RV FAQ section. I looked it up for you and here is the copy. Using the "rule of thumb" of 20 feet for 110 inches of wheelbase and an additional foot for every 4 additional inches, remember that it is a rule of thumb theory and as stated above weight is oh so important. hitch set up is in there too, many things to work out.

Here's a link to a PDF that gives some explaination, look at part 5: Click here.

He does not give any formula, he does summarize by saying the longer the trailer the longer the tow vehicle wheel base should be, but does not give any numbers. Interesting read though.

Here's another unanswered forum also sprung from an article in Trailer Life magazine: IRV2 forums Click here