Manufacturer model length vs actual tongue-tail length

[SlowBro]

For the purposes of towing, the length one should consider is the actual tongue to tail length, not the manufacturer's model length, correct?

For example mine is a 25QB but the measured tongue-tail length is 27' 5". And I'd use the second number in towing calculations.

I've already bought my TT and TV so this is more just for my edification.

[mtofell1]

humblerb wrote:
For the most part, the number in the model number is the length of the cabin of the trailer. Does not include bumper or tongue lengths.
There are exceptions, but most of the time, this is true.
And it is an estimate, even at that.

I'd say this is true 75% of time which in my book means "most of the time." Add 3-4 feet for the total bumper to ball in (again) "most" cases.

[wandering1]

humblerb wrote:
For the most part, the number in the model number is the length of the cabin of the trailer. Does not include bumper or tongue lengths.
There are exceptions, but most of the time, this is true.
And it is an estimate, even at that.

The model number is the model number and has nothing to do with trailer length ,all of the time, this is true. :S

[tatest]

The model number is a model number, it is not a length. If a manufacturer applies any meaning to the number, it more often helps to rank individual models by where the manufacturer wants the price point to be. Even from the same manufacturer something with a 29 in the number could be three feet longer than something with 30 in the number.

The manufacturer will have length specifications for each model. These will be tongue to rear bumper (if it has a bumper). It will not necessarily include length added by accessories like rear-mounted spare or a ladder, so be aware of that if shopping to fit a garage or driveway space.

[Nik]

We are shopping now, and have a very tight parking spot, so I've become a little obsessive about trailer lengths. The model number has absolutely nothing to do with the length of the trailer. We are looking at a "17" as I speak that is 22 feet long.

[humblerb]

For the most part, the number in the model number is the length of the cabin of the trailer. Does not include bumper or tongue lengths.
There are exceptions, but most of the time, this is true.
And it is an estimate, even at that.

[JBarca]

cdevidal wrote:
Ok thanks everyone, I had a slight question in my mind wondering if length and its effect on the vehicle had more to do with the massive wall of box itself or the actual length.

As for towing calculations, I'm talking about the 110" wheelbase rule-of-thumb. I understand it is a verrrrrrrrrrrrrrrrry loose rule though.
http://www.rv.net/forums/index.cfm/fuseaction/thread/CFB/1/TID/307610.cfm

I would use the ball to bumper length as the length.

As far as length rules and wheelbase, I have read that the rear overhang of the truck should not exceed 1/2 the TV wheel base. Rear over hang being distance from tow ball in the shank to the center of the rear axle.

That rule of thumb has some more merit to it then the older Consumers group length.

I use to tow with a 2500 Suburban. 130" WB with a 65" rear over hang. The rear overhang is 1/2 the wheel base.

In that situation, the stiffer truck suspension made a more stable towing platform then the 1500 counterpart Suburban.

And that said, on my 2500 Burb, changing tire brands of LT Load Range E tires had more to do with towing stability then the length of the trailer. I towed my prior 27 footer with great success until I bought new tires. Then sorted that out and towed our current 32 foot with it until the F350 came. The towing stability I could tell was more affect by the tires on the truck then then 5 extra feet of trailer length.

When the F350 came, I grew a longer WB and more stable truck suspension once again. There was a global shift in stability then.

From my experience, trailer tongue weight to TT GVW balance, TV tire and suspension stiffness have more effect on stability then trailer length as long as you are under 35 feet TT length. I do not have experience longer then the 35 foot. I would however the keep rear overhang to not exceed 1/2 the WB rule.

Good luck with your new rig.

John

[heckufaguy]

I had a 19 foot (22 total) trailer and just got a 26(almost 29) foot trailer. The first had more of a solid front, with just a slight upwards slope. The newer is very rounded slope, and although we only towed it home from the dealer, we were towing in to the wind, and still were able to keep the RPM's lower per speed than we were taking the shorter one in for the trade. I'm hoping I see that result on our first trip too.

[SlowBro]

I suppose that rule-of-thumb was written out based on what had been noticed by experienced trailer haulers. They saw that more than 20 feet of trailer on a 110" wheelbase TV tends to be more unstable. However, that rule-of-thumb doesn't take into account frontal area, nose up vs. down, tongue weight percentage, etc. I imagine though that all things being equal, it's pretty close to a good help.

That said, by that rule I should be towing no more than 22 feet. I'm at 27 feet and even without any weight distribution or sway control it's been rock steady. I think I'm benefiting from a smoother frontal area. So far though I've only towed it unloaded, with no passengers, no more than 55mph. Will see what happens come vacation time. (Yes I will use a WDH and sway control then. We'll likely keep it under 60mph since it's our first trip, and we'll be taking the side roads not interstates when possible.)

[Bedlam]

Although a longer wheelbase will be more stable when towing, I would not call it rule. When I towed a popup with a Bronco II verses a Mazda extended cab short bed, the longer Mazda handled the trailer better due to stiffer suspension and longer wheelbase. My short bed extended cab F250 had no trouble with a tall heavy toy hauler

http://www.rvforum.net/SMF_forum/index.php?topic=26747.0

[wandering1]

Sounds like 25QB is part of the model number not the trailer length. The model number is the model number and has nothing to do with the trailer length.

[SlowBro]

Ok thanks everyone, I had a slight question in my mind wondering if length and its effect on the vehicle had more to do with the massive wall of box itself or the actual length.

As for towing calculations, I'm talking about the 110" wheelbase rule-of-thumb. I understand it is a verrrrrrrrrrrrrrrrry loose rule though.
http://www.rv.net/forums/index.cfm/fuseaction/thread/CFB/1/TID/307610.cfm

[Bedlam]

No towing calculations take length into consideration, but whether to use one or two friction anti-sway devices is usually approximated using length. Overall length is important for camp site selection and ferry fees. If your tow vehicle is long or you tow doubles, additive lengths are important so you stay under maximum allowable where you plan to travel.

[VintageRacer]

What towing calculations do you do that use the trailer length? Just curious.

Brian

[JesLookin]

If you look at the brochures there is usually a statement saying that the model number is only the model number and is not intended dsecribe the length of the camper.