Dual cam VS Equalizer...I have both

chipster wrote:


Dual cam, uses the cam method to stop sway by applying more force when the trailer tries to push the bars out of the locked in cam position. Only problem I see is this cam fitment is very very poor. Look at your wear marks on the bars and the cams themselves and you will be lucky if more than a third of the surface area has any wear marks. Thus not providing near as much friction or metal on metal area the equalizer does. Also the trunion style bars have so much play in them at the connection point on the head. Sure under weight will they move not likely but they can where the equalizer has no play thus to me providing an overall better hook up.

My tongue weight is 1650# so I am inclined to keep using the Dual cam but if I had the 1400# setup for the Equalizer I think I would go that route.

Plus the Equalizer is so much easier to set up, trying to get the cams seated 100% takes some time, and also if the TV and Trailer and not loaded exactly every-time it could change the geometry of cam position not seating 100%. Equalizer flat surface, no worries.

Hi chipster,

I just want to try and help you understand one of your thought processes is not correct. It "appears" you are saying that the amount of surface area of DC contact makes the Reese less effective than the Equal-I-zer because the EQ has more surface area contact. Did I under stand this correct?

If so, that is not a correct thought process. Technically the amount of surface area in contact does not enter into the equation of how much force it takes to break free a friction holding system. I know this sounds strange, but it is one of those Laws of Friction.

Quoting Irvnig Levinson in his 1971 Text Book, Statics and Strength of Materials page 114 has these 3 points about the Laws of Friction:

Levinson wrote:
These laws state that when one solid body slides over another, the frictional force is:
1. Proportional to the pressure force between the bodies,
2. Independent of the area of contact, and
3. Independent of sliding velocity.

Using the formula below which states.

The max Force required to start an object moving (F) = Force normal (N) or the perpendicular weight of an object acting on a surface X the Coefficient of Friction (f)

F = N X f

See here:
Friction and coefficients

Surface area does not enter the equation. To increase holding power of WD bar from sliding, you either create more force acting on the bar or you change the coefficient of friction between the 2 objects.

Think of it this way. Put a cardboard box which measures 12" x 12" (1 sq foot)on your concrete drive way and put 10# of weight in it and then push or pull it. The force to break free the static friction and make it start sliding will not change if you have a box 1 sq ft. of area or 3 square feet of area. If you increase the weight in the box, then the force to start it sliding goes up proportional to the increase in weight.

Both hitches are very good and very close in effectiveness. Neither will fix a problem of sway in your TV & Camper combo by changing hitch brands. The problem is the elsewhere then the "brand" of hitch if you have a problem.

Both hitches have pros and cons due to the way they are built. I myself prefer the Reese trunnion bar DC. I will not buy the round bar Reese due with the DC due to the lack of hitch head tilt adjustment.

As far as DC wear, see my cams with 24K miles on them, notice the date.




Here are the 1,200# bars that worked with them


I am now a little over 50K miles on the same cams with 1,700# bars and a TW of 1,500 to 1,600# pending loading. The wear on the cams is not a lot more then what you see in those pics. I mark the WD bars left and right and always put them on the same side. If not, you will start a new wear pattern over and over again.

When the cams are brand new, metal dust will form quick as the high spots on the WD bars make their mark in the DC. It tames down in ~ 1K to 2K miles and then wears less as the contact patch increases. Due to my high TW, I do use a real light coat of vase-o-line on the cams. While yes there is a very slight loss of holding power, my rig is stable with no sway control and I do not notice any loss of holding power. But I do notice less noise and wear.

Good luck and hope this helps

John

PS. When the DC is set correct and you are talking TW's of 1,200# and up, changing TW loads of ~ 100 to 200# will not affect DC setting. Set it correctly, keep the WD bars on the same side and you are all set unless you change 200# or so plus TW change.

I've been using the DC setup for over a dozen years. From 2000 to 2004 I was using the DC with round bars and from 2004 to present I've been using the Dual Cam HP with the trunnion head.

Other than the setup needing some babysitting to make sure the detent of the spring bars hit the cams properly under various loading, I didn't have any trouble with the DC and was actually very pleased with it.

Two years ago when backing into a site with a little more angle than normal, I had a cam arm break.

Just over a week ago when towing over the horrible stretch of I-5 between Seattle and Tacoma, a cam arm got bent significantly.

While looking into a fix and hoping to avoid any further failures, I learned from 'Greg' at Trailer World just outside Bend, Oregon that when Cequent bought Reese a few years back, they began outsourcing components (including the cam arms) from China. He said he had been a long term proponent of the Dual Cam and had installed more of them than anyone else in the state. He now does a lot of installs for the military and says the Equal-i-zer is the only hitch that meets all their requirements. He also didn't have to work all that hard to convince me that the Equal-i-zer was considerably more fail-safe than the DC.

I called Cequent and they overnighted a brand-new Dual Cam HP set to me where we were camping. When I opened the box I saw that they had made a number of design changes since the new set I had purchased a couple years ago. The changes appear to be designed to improve the contact area between the spring bars and the cams, but also required me to drill new holes in the tongue frame to keep from having to use an excessive length of the cam arms (which would've made them more susceptible to bending).

I'm still satisfied with my DC setup, but if I was starting from scratch today I would most likely go with the Equal-i-zer. Unfortunately, it doesn't look like they have anything for tongue weights over 1200 pounds, so the OP may not have that option if they wish to stay within manufacturer ratings.

BenK wrote:
Anyone either know of where or can empirically provide the actual forces these
take to go off center?

Frictional resistance of a trunnion through that snap bracket (think the actual
friction is the downward force on the 'L' bracket).

Both the frictional force and the run up that incline of a bent end bar on a cam

Of course dependent of factored by the WD bar force and that has a dynamic
component as the alignment goes off center

Then all that is factored by the differing centers between the ball
and bar pivots...that then depends on how the chains are captured
by the hookup to the tongue. Question on this...are all brands
WD bar pivot center vs ball center the same distance?

Can see why there has been reports of the Blue Ox bars bending and breaking
because I think their chain latch is cool and adds to anti-sway...so
much that it doesn't allow the bar end to move as much as other OEMs
chain latchup architecture

Campin LI wrote:

Ron Gratz wrote:
The sway-control effectiveness is determined almost entirely by the base force applied to the WD bars. `The additional force due to lifting of the bar by the cam and due to differences in bar stiffness is negligible.
IOW, friction has everything to do with it.

Ron

This post was a great explanation. Thank you for the education. Also, relative to the quoted portion of the post, Reese makes a round bar WDH and if you read the directions, to install it correctly, the bars are to be parallel to the trailer frame. Reese never makes a claim that their trunion bar setup provides more sway control than their round bar setup.

I'm not sure I follow your question. I think friction forces are different for every trailer and every setup. Generally, the heavier the hitch weight, the more friction you will be able to produce. That's why lighter trailers usually have those add on sway control things (don't know the name but they are 2 friction pads on an adjustable bracket that attach to 2 small hitch balls). They use those because A) No weight distribution hitch is needed because the hitch weight is too light or B) The hitch weight is too light for an Equal-i-zer or Reese dual cam to produce enough friction to be effective.

These 2 companies market these hitches for weight distribution and sway control. Weight distribution definitely happens and they work, but notice they all say that they provide sway control but never put a number to it like they do for weight distribution. It's because sway control is related to friction. If you don't have a lot of friction, you don't have a lot of sway control. You need weight to produce friction.

I had a Reese dual cam some time ago but I could not get it to work well with my setup. When turning, I never felt any difficulty getting the cam to unlock. Actually never considered that it would be a problem. In fact, mine used to bend all over the place while traveling and I never knew until I got to my destination and looked. If the trailer sways, its going to unlock it easily.

Anyone either know of where or can empirically provide the actual forces these
take to go off center?

Frictional resistance of a trunnion through that snap bracket (think the actual
friction is the downward force on the 'L' bracket).

Both the frictional force and the run up that incline of a bent end bar on a cam

Of course dependent of factored by the WD bar force and that has a dynamic
component as the alignment goes off center

Then all that is factored by the differing centers between the ball
and bar pivots...that then depends on how the chains are captured
by the hookup to the tongue. Question on this...are all brands
WD bar pivot center vs ball center the same distance?

Can see why there has been reports of the Blue Ox bars bending and breaking
because I think their chain latch is cool and adds to anti-sway...so
much that it doesn't allow the bar end to move as much as other OEMs
chain latchup architecture

Campin LI wrote:

Ron Gratz wrote:
The sway-control effectiveness is determined almost entirely by the base force applied to the WD bars. `The additional force due to lifting of the bar by the cam and due to differences in bar stiffness is negligible.
IOW, friction has everything to do with it.

Ron

This post was a great explanation. Thank you for the education. Also, relative to the quoted portion of the post, Reese makes a round bar WDH and if you read the directions, to install it correctly, the bars are to be parallel to the trailer frame. Reese never makes a claim that their trunion bar setup provides more sway control than their round bar setup.

Mine were like that when i first got it. After a thousand miles they are sitting flat!

Ron Gratz wrote:
The sway-control effectiveness is determined almost entirely by the base force applied to the WD bars. `The additional force due to lifting of the bar by the cam and due to differences in bar stiffness is negligible.
IOW, friction has everything to do with it.

Ron

This post was a great explanation. Thank you for the education. Also, relative to the quoted portion of the post, Reese makes a round bar WDH and if you read the directions, to install it correctly, the bars are to be parallel to the trailer frame. Reese never makes a claim that their trunion bar setup provides more sway control than their round bar setup.

All great thoughts everyone, thanks, there's always something to learn.... Get the oh yeah, I never thought of it doing that...

I'll probably stick with the heavier dual Cam setup, but like my original post stated, the seating of the Cam in the bars is very poor and I traveled over 10,000 km with previous dual Cam setup and still did not wear enough to seat properly. Why not just build them right in the first place. I'll post pictures of the wear pattern after my next trip. About 2000 km round trip.

Several posts have been deleted for being "off topic". See the title of the thread and please keep your remarks on it and not other hitches.
Barney

Now my head hurts!

Ron Gratz wrote:

jerem0621 wrote:
Yes, DC is proactive... Equal-i-zer and friction bars are static or dumb or whatever you want to call them.

Jeremiah, how do you define "proactive" in this context. IMO, all friction-based sway controls are proactive.

Ron

I used the wrong word. I meant to say reactive. When the DC Crook in the bar rides up the cam in a sway event the friction is increased. Instead of with a friction bar or the Equal-i-zer friction which doesn't have a self centering action.

You are quite correct, The use of any sway control is proactive.