What's the difference between a trailer and a 5th wheel, besides the obvious?

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.

Nick

Member
Joined
May 4, 2008
Posts
5
Location
Longview, TX
Hi,

New guy here.  Been doing a little reading and I'm wondering if there is any real difference between a trailer rv and a 5th wheel, besides how they attach to the tow vehicle?  What are the advantages and disadvantages of one over the other?  Are prices about the same for comparably sized trailer/5thwheels?

Thanks,
 
A fifth wheel is usually a bit heavier, longer, taller, and thus can have a bit more interior items, room, and so on.  Take a look at both and you will quickly notice the difference.
 
The biggest reason for a 5th Wheel over a traditional trailer has to do with the fact that you can be a bit longer (over all) and, the handling is much much better.

This is why semi's are 5th wheel.  Easier to pull, easier to steer, easier to back up  WAY easire to back up
 
I've owned both travel trailers and 5th wheel trailers.  The biggest difference between them is the handling.

A 5th wheel hitch is inherently more stable than a conventional hitch located several feet behind the rear axle.  With the pivot point directly over the rear axle as in the 5th wheel setup, side forces on the trailer are transmitted directly through the truck's rear axle to ground with minimal effect on the stability of the rig.

A conventional trailer's hitch point is several feet behind the tow vehicle's rear axle.  Push sideways on the rear bumper of a vehicle and it will pivot around the rear axle, moving the the front in the opposite direction.  Left uncorrected, this will cause the combination to oscillate or sway, and is why you really can't tow a conventional trailer successfully without some kind of sway control.  Sway controls stiffen the hitch pivot - in effect masking the symptom instead of fixing the underlying problem.

Backing a 5th wheel is slightly different than backing a conventional trailer.  One is not easier to back than the other - they just respond differently.  A conventional trailer will begin to change direction immediately at the start of a backing maneuver because of the leverage between the hitch point and the truck's rear axle.  With a 5th wheel, you have to input more change (actually change the angle of the truck with respect to the trailer) before you have any effect on the trailer's direction of travel.

One more difference - for any given wheelbase (length from the trailer's hitch to the rear axle), a 5th wheel will offtrack more than a conventional trailer.  Offtracking means the trailer's wheels will turn a corner inside the path of the tow vehicle's wheels, so you have to swing wider around corners with a 5th wheel than with a conventional trailer with the same wheelbase.

A conventional trailer offtracks less because the overhang between a conventional trailer's hitch and the rear axle moves the front of the trailer outwards during a turn, causing the trailer axles to more closely follow the track of the tow vehicle.
You can see this principle most clearly in logging trucks - the hinge point between the tractor and trailer is halfway between the truck's rear wheels and the trailer's wheels, so the trailer axles almost exactly follow the truck's path.

The bottom line is both conventional trailers and 5th wheels can be towed successfully.  But the 5th wheel arrangement has several inherent advantages that make it more forgiving than a conventional trailer in less than optimum situations.
 
Nick said:
Hi,

New guy here.  Been doing a little reading and I'm wondering if there is any real difference between a trailer rv and a 5th wheel, besides how they attach to the tow vehicle?  What are the advantages and disadvantages of one over the other?  Are prices about the same for comparably sized trailer/5thwheels?

There are real differences between travel trailers, TTs, and fivers:

1.  Tow vehicles:   Fivers require a pickup truck preferrably long bed, or, in extreme cases a medium duty trailer tractor.   TTs can be towed by pickups, vans, SUVs, most anything with a frame to attach a hitch to.

2.   Steering:   Fivers tend to cut inside of a turn and thus require that a sharp, right-angle turn be taken wide, just like semi-trailers do.  TTs track the tow vehicle exactly.

3.   Stability:   A TT requires a weight distributiing (WD) hitch with anti-sway provision but when provided with them is stable in cross winds and the shock waves of passing vehicles.   A fiver is inherently stable with respect to these hazards.  That said, the hitch systems of both cost the same with the economy nod going to TTs.  

4.   Hitch weight:  Fivers have significant hitch weights (15-20% of trailer weight) which must be borne within the gross rear axle rating of the tow vehicle -- this is why dual rear wheel trucks are so common with big fivers.   The hitch weight of the TT which is between 10 and 15% of trailer weight is evenly distributed between tow vehicle front and rear axles by the WD hitch.

5.  Frontal and longitudinal X-section:   The fiver, length for length has a larger, higher, frontal and longitudiinal x-sections than a TT.   The TT sits lower.  This affects wind resistance and overhead problems in campgrounds.

6.  Floor plan:   TTs have a flat floor plan and more living space per unit length.   Fivers have more storage areas and often a basement for them.   TTs sit lower to the ground at their doors.

7.  Size:  Because of their combined characteristics TTs dominate the short length and light weight trailers; fivers dominate the long lengths and heavy weights.  They overlap in the 26 to 30 foot lengths.

Ya pays yer money an ya takes yer cherce.   ;D
 
John In Detroit said:
This is why semi's are 5th wheel.  Easier to pull, easier to steer, easier to back up   WAY easire to back up

I disagree that a 5th wheel is easier to back up than a TT.  It takes a larger cranking of the steering wheel to turn a 5th wheel trailer when backing up than it does on the TT.  So when backing into tight spots, it is easier to back the TT in without making hard turns with the tow vehicle. Actually, neither one is too bad once you you get a bit of experience.
 
Agree, Lowell. Was waiting to see if anybody would disagree with John on that score.

A travel trailer indeed responds more quickly to steering input when in reverse and most people find them easier to handle when backing. It also tracks behind the tow vehilce more closely when going forward, i.e. it doesn't "cut the corner" as much as fifth wheel of the same length.

Semi's are indeed very maneuverable when backing, but it is mostly because the trailer wheels are all the way at the back, which alters the geometry considerably. Good for backing, but it also increases the lag in turns when going forward. Fifth wheel trailers have the axles further forward, so are not as agile at backing.

All that said, either one can be maneuvered quite easily by any driver who takes the time to learn how.
 
RV Roamer said:
Semi's are indeed very maneuverable when backing, but it is mostly because the trailer wheels are all the way at the back, which alters the geometry considerably. Good for backing, but it also increases the lag in turns when going forward. Fifth wheel trailers have the axles further forward, so are not as agile at backing.

Gary, Does this lag (due to difference in trailer wheel position in 5er vs. Semi) mean that it's not necessary to cut curners in a 5er as wide as Semi drivers do while turning going forward?  I'll be picking up my 5er next week and don't want to take any poles or fire hydrants along with me on the way to the CG  :eek:  Then again, I don't want to over-compensate.  I've paid attention to how wide Semis make turns before, but not 5ers.

Thanks
Gary 
 
RV Roamer said:
Agree, Lowell. Was waiting to see if anybody would disagree with John on that score.
All that said, either one can be maneuvered quite easily by any driver who takes the time to learn how.

Great answer Gary, As Tom would say, "spot On"

Jerry
 
The truck and fiver takes up less room beside the house when I'm not using it...which is 99% of the time ;)  Can squeze both into a smaller campsite too.

Seriously though, like everyone has pointed out, the difference in stability is night and day.  And for those of us who live in the desert Southwest where high winds are common, this is a big benefit.  Towing the fiver in a 35 mph crosswind is no big deal whatsoever as long as speeds are kept reasonable.  I can't say the same about the last TT I had.....things could get hairy in high winds.

Backing isn't really harder or easier, just different.  An hour in an empty parking lot with some cones and you'll have it down. 

The real joy is when hooking up a fiver versus a bumper pull.  Quick and simple.  Tons easier than trying to get a 2" ball to line up into a conventional hitch.
 
Does this lag (due to difference in trailer wheel position in 5er vs. Semi) mean that it's not necessary to cut curners in a 5er as wide as Semi drivers do while turning going forward?

I'll answer that with a qualified "yes". The qualification is that without an apples to apples comparison as far as wheel base on both trailer and tow vehicle, the answer is pretty much meaningless. 

It's the trailer wheelbase that is the critical factor.  The effective wheelbase of the trailer is the distance between the pivot (hitch) point and the axle it turns on.[ Usually the axle turning point is actually between the two in a tandem axle and the middle axle of a triple axle trailer.]  Your fifth wheel won't be as long as the semi to begin with and will have its axles further forward, so you will not have to go anywhere near as wide as a typical semi.  But you still have to pull further forward before starting the turn and cut a bit wide as well. Watch those side mirrors carefully. Do NOT attempt to tow the trailer without good mirrors that allow you to see clearly down both sides of the trailer, which means mirror extensions or special door-mounted towing mirrors on most tow vehicles.
 
Nick said:
Hi,

New guy here.  Been doing a little reading and I'm wondering if there is any real difference between a trailer rv and a 5th wheel, besides how they attach to the tow vehicle?  What are the advantages and disadvantages of one over the other?  Are prices about the same for comparably sized trailer/5thwheels?

Thanks,

OK, I'll be straight with you: I'm a TT guy and don't much like 5ers.

Now, more opinion:

Most fifth wheel trailers are very high because if the part of the trailer over the pin isn't high, there is not enough headroom in the bedroom. (Rhyme not intentional). This also increases wind resistance.

When you hookup or unhook a fiver, you are dependent on the 12 volt front jacks to raise the front end of the trailer. Some TT's have powered front jacks, too, but I don't like 'em. I admit to predjudice about this.

The floors of many fivers are also very high off the ground so that the trailer can clear the sides of a pickup bed to allow turns. They need three or four folding steps on the outside. I don't like this. At the same time, just inside the door, there is often another a step up into the trailer interior. Everything you carry into or out of the trailer has to go up or down all these steps.

I don't like split bathrooms and these are common on fivers.

You can only tow a fiver with an open bed pickup or with some specialized vehicle made just for that purpose. I like to carry to stuff in my truck that I don't want in my trailer & I want that stuff out of sight and locked up. Fivers have lots of basement storage and they need it because you can't carry stuff in the truck.

Obviously, thousands of fifth wheel owners are not bothered by any of this.

John Alldredge
[edit]Fixed quote tags.[/edit]
 
I replaced my TT with a 5th wheel when i wrecked it I got into an uncontrolled sway condition and ended up in the ditch on I-94

I like it for the stability, but miss the storage in the bed of my truck.

 
I like my travel trailer.  If I was going to get a bigger trailer and tow vehicle I would probably give a good look at a fiver.

I like the flat floor plan of a TT as I am a bit beat up and the ups and downs are a problem for me.  So the flatter the better.

But my TT and TV were both bought new last spring so I expect it will be a while before I update.
 

Members online

Forum statistics

Threads
131,749
Posts
1,384,209
Members
137,520
Latest member
jeep3501
Back
Top Bottom