Tandem Axles?

[Pete Dumbleton]

E Z Flex

[Frederick L. Simson]

I gotta look into getting a pair! Thanks, Pete!

[Darwin Maring]

Bout time, they had a similar item on the WWII Sherman Tanks.

[Lynn Peters]

I think I will look into these, too. Frederick, if you get some let me know how they work. I will be travelling on rough roads a lot now that I'm in WA/ID and they might help.

[Brian B-P]

Thanks, Pete - I'm always interested in suspension technology, an I had not heard of a Dexter product of this type.

This type of device is available from a few sources, with either rubber or air springing, although the Dexter rendition (which is rubber-sprung) looks particularly tidy. Whatever the brand, their very existence proves that leaf-sprung trailer suspensions are too stiff. The ride improvement which Dexter shows in their test results is the simple and direct result of softer springing. If I had tandem axles (my Boler does have leaf springs, but only one axle), I would ensure that I was using the softest spring pack allowable within weight capacity requirements before resorting to a device like this.

Too bad the Dexter design uses greased plain bushings (see the grease fittings?), thus adding another maintenance item and a potential source of future problems when they wear out.

[Pete Dumbleton]

Too bad the Dexter design uses greased plain bushings (see the grease fittings?), thus adding another maintenance item and a potential source of future problems when they wear out.

I had the same thought.

Also, I posted this on another group, with lots of dual-axle people on it and it was greeted with a LOT of skepticism and lumped with fuel magnets, etc., as devices for separating suckers from money, so I am keeping an open mind about this. Generally, I feel Dexter is a reputable company, so if I had dual-axles I would be looking further into this, with the big question being How Much?

[Frederick L. Simson]

...it was greeted with a LOT of skepticism and lumped with fuel magnets, etc., as devices for separating suckers from money, so I am keeping an open mind about this. Generally, I feel Dexter is a reputable company, so if I had dual-axles I would be looking further into this, with the big question being How Much?

Being as I am ready to install shocks; this sure looks a lot simpler to install.

[Brian B-P]

Despite my reservations, and my insistence that there is a better solution, I do believe that this device would work approximately as claimed with existing springs. Would it work well enough to justify the cost? Who knows... does anybody know how much these things cost?

The equalizer exists to share load between the two springs and thus the two axles, and this device dstill oes that while also placing a rubber spring in series with the leaf springs, reducing overall stiffness. You could probably use a nearly identical device as a shackle at the end of a single leaf spring and have the same effect of softening while maintaining axle control.

There is one problem I see with softening the leaf springs: the roll stiffness would be reduced, and I think many trailers (including mine) have too low roll stiffness already.

[Brian B-P]

Being as I am ready to install shocks; this sure looks a lot simpler to install.

While I agree that this would be simpler to install (especially since you tandem people need two sets of shocks), I do not think that this is an alternative to shocks at all.

Shock absorbers, or dampers as the British appropriately call them, reduce suspension oscillations by absorbing energy when the suspension moves; they also reduce movement with by adding resistance. They do not affect the spring stiffness.

The E-Z Flex has some built-in damping of its own spring movement (since it uses rubber), but will not damp the steel spring flexing at all. I would expect it to allow more trailer movement, rather than less, although it should at least soften ride without making oscillations worse.

Now you have [b]two suspension projects, Frederick!

[Brian B-P]

Okay, after some time pondering, I'll admit that the device could somewhat assist damping: it does not directly help the poorly damped leaf springs because it cannot respond to their motion, but since it will move with the changing forces of the leaf springs bouncing, and its motion is somewhat damped, it will absorb some energy and might help a bit like shock absorbers.

I still don't see it as an effective alternative to shock absorbers.

So, Frederick, I know that you have been considering shocks for a while now... what problem are you looking to solve: Ride? Stability? Responsiveness? The shocks which I added to my Boler helped in all areas, but presumably would not help soften the ride like these Dexter things.

[Frederick L. Simson]

So, [b]Frederick, I know that you have been considering shocks for a while now... what problem are you looking to solve: [b]Ride? Stability? Responsiveness? The shocks which I added to my Boler helped in all areas, but presumably would not help soften the ride like these Dexter things.

I'm looking to soften the ride. The Fiber Stream is an extremely stable tracking trailer, and I find it adequately responsive to steering and braking. I'm concerned that using weight distribution may be too harsh on the frame, although I do not have it cinched up very tightly. I have stiffened the frame to try to solve a sagging problem aft of the 2nd axle spring attachment. I just notice a vertical bounce in the trailer in my rear view mirror while the van glides along smoothly.

I still don't see it as an effective alternative to shock absorbers.

I'm not biased against a belt-AND-suspenders approach...

[Pete Dumbleton]

I don't know how much these cost, but something similar from an outfit called MOR/ryde costs in the neighborhood of $450 for the parts, so I'd be inclined to go with actual shocks because they will give a better ride even when both axles are moving at the same time (I think the Dexter product is more effective when only one axle at a time is moving, like a pothole strike).

[Brian B-P]

Pete's link points to a massive version of the rubber-sprung shackle idea which I mentioned earlier, known as the RL (rubber leaf) system.

The corresponding MOR/ryde product to the Dexter E-Z Flex is the RE (rubber equalizer) system. It is much larger and more complex than the Dexter product, so although the Dexter system may be less effective, it should be much cheaper. By the way, the Dexter site features the E-Z Flex on the home page, but I don't see it anywhere else on the site, so it looks like getting more information means e-mail or a phone call.

As equalizers, these devices have little response to one axle moving up while the other one moves down, so a one-axle bump should have less effect than both at the same time.

I still vote for shocks first: they won't interfere with any other plans, and may avoid the need for anything else. If it were me, I would add the shocks first (as I have on my Boler), then the trailer with the WD system disconnected - it may be smoother riding and well controlled without all that extra stuff.

By the way, MOR/ryde also sells something like the "rubber torsion" axles common in eggs (but using shear blocks) as the IS (independent suspensions) system. They seem to be determined to find as many applications as possible for the rubber-in-shear blocks.

[Pete Dumbleton]

Brian's right -- I did post the wrong link to the MOR/ryde product.

To get to the Dexter E-Z Flex, from the main page open the "Products and Literature" menu and then open the "Other Dexter Products" menu.