Axle-Less AxleLess Suspension - TIMBREN

[GPJ]

Originally Posted by Jared J

Technically, then I would think it wouldn't be a torsion axle.

That's very true! I believe that many of what we call torsion axles are not true torsion axles -they compress rubber cords rather than twisting them.

[Jared J]

Yeah, It doesn't really matter, just something I didn't think of before. I've called mine torsion, and it has rods as you described.

[Andrew Gibbens]

Looking at the Timbren data the total suspension movemnent at the wheel looks to be about the same 2-3" (unloaded to full bump) as almost any torsion trailer axle. That compares to the 6" or more on most tow vehicles (and maybe on franck2cv's German trailer).

Without suspension travel, the springing has to be stiff so the ride is not going to be soft. Changing the type of spring (steel, rubber, air) doesn't affect that much, however fashionable one or other type is.

I agree with the previous posters who point out that "axle-less" suspension just mean the axle's strength has to be built into the trailer frame.

I think lining up two separate half-axles is a concern in North America as so few people do it. In Europe, half-axles are common on small trailers (though not on travel trailers, if I'm getting my US terminology correct) and lining them up is not rocket science - tape, string and chalk is what's used, not lasers and telescopes.

[franck2cv]

Originally Posted by Carol H

Franck having spent time driving in many parts of your wonderful province as well as having put in a few miles in California and Arizona I would suggest they have you bet in regards to rough roads. I don't recall while driving in Quebec thinking the roads were any more rougher than those in BC. Can't say the same for California and Arizona though. They do indeed have some surprisingly rough riding freeways, as well as minor highways to the south of us.

Thanks.... I'll have something to say to the forever grumblers.... Whom I've been part of lately!! I still have Vermont and NY state to enjoy smooth roads!

[franck2cv]

I took it for granted that the Suspension travel was greater than 'traditional' rubber rods (not) torsion, (not) twisting, flexride like axles.....
It's not and is a bit of a disappointment. The higher rating one (3000lbs) has a longer travel but makes no sense on our desired travel trailer.

In an ideal world, we would need a documented test ride with two identical trailers equipped with those different suspension designs....

[Francesca Knowles]

Is it the opinion of the group that a crossmember added to the frame at the point where the "axle" would be should be sufficient frame reinforcement?

I don't see this as a big deal- my main interest is removing as many underslung impediments as practicable, and an against-the-body crossmember would be fine with me...

Francesca

[ruscal]

Originally Posted by Francesca Knowles

Is it the opinion of the group that a crossmember added to the frame at the point where the "axle" would be should be sufficient frame reinforcement?

I don't see this as a big deal- my main interest is removing as many underslung impediments as practicable, and an against-the-body crossmember would be fine with me...

Francesca

Francesca
It seems that a square tube inserted into the pocket of the suspension member would help counter the cantilevered loads that would have had to be resisted by the frame mounts alone. Since our trailers weren't designed to handle those loads It would be good insurance to add the cross member.
That cross member may be tucked up to the frame a little higher than the typical torsion axle tube, but your not buying much more clearance. If you do a lot of off-road travel you could "joggle" the cross member up between the frame rails and back down to buy a couple of inches if there is no other stuff in the way.
Russ

[Andrew Gibbens]

I think retro-fitting this suspension to an existing egg is going to be hard unless the cross-member is added between the two half-axles as shown in Timbren's instructions - in which case it becomes a whole axle that you have built yourself.

If the cross-member is to go up in the frame, there's going to be quite a lot of welding right by the floor, so having more than one fire extinguisher nearby would be good.... And unless the ends of the newly-added cross-member is almost touching the half-axles, the strength of the connection between those two needs to be considered.

So for example, I would be nervous doing this on an 'open section' frame rail like a C-channel which doesn't have much torsional strength. If the main rails of the frame are rectangular tube, which most modern eggs are, I believe, then they can probably survive, maybe with a little local reinforcement.

Anyone doing a body-off restoration would be in a different position as there would be full access to fit the cross-member in the best place.

[Brian B-P]

There is nothing more or less "axleless" about the Timbren design than any other independent suspension. Like other designs, it does have axles - one stub axle at each hub.

Originally Posted by franck2cv

Then I bought an old East German model with a long travel horizontal suspension (photo).

That's a nice design!

Originally Posted by Bob Miller

Not to bring up "Old and Rudimentary" again (but I will anyway), but don't U-Hauls use a similar system of no axle suspension.

U-Haul used "rubber torsion" suspensions essentially interchangeable with the independent suspensions used on most (but certainly not all) moulded fiberglass trailers.

Originally Posted by ruscal

The replaceable rubber spring looks to be an advantage over the enclosed torsion spring design as far as serviceability goes.

The rubber cartridge of a Flexiride is also replaceable. I agree that this is an advantage, and the Timbren blocks should be cheaper and easier to replace than the Flexiride cartidges - if they are available in a couple of decades. These are the same spring blocks which Timbren sells for other purposes, so availability might not be a problem.

Originally Posted by GPJ

I believe that many of what we call torsion axles are not true torsion axles -they compress rubber cords rather than twisting them.

The Flexiride design deflects a hollow rubber tube in torsion, so the rubber strains in shear. Rubber springs used on heavy trucks and in some rubber-cushioned fifth-wheel hitch designs deflect flat rubber blocks in shear between steel plates. Other rubber springs "squash" the rubber, but it doesn't really compress - it still moves in internal shear, but not evenly and thus not efficiently. The Timbren design is in the "squash" category, and both Dexter Torflex and AL-KO designs "squash" rubber rods.

[Brian B-P]

Originally Posted by honda03842

Etrailer has an article on axle less suspension, comparing it to traditional suspensions.

Timbren Axle-Less Trailer Suspension System - Straight Spindle Only - 3,500 lbs Timbren Trailer Suspension ASR3500S05

Thanks Norm.

I doubt that the writer is interested in suspension systems or understands much about them, since the comparison with "traditional" rubber trailer suspensions is largely nonsense. As others have already noted, the "traditional" design is also available in separate left and right units without an integral crossmember, and none of the discussion of how the rubber springs work means much.

I have no concerns with the Timbren design; it's just the eTrailer article which is questionable.

[Jared J]

Originally Posted by Brian B-P

There is nothing more or less "axleless" about the Timbren design than any other independent suspension. Like other designs, it does have axles - one stub axle at each hub.
, so availability might not be a problem.
.

I would call them spindles, not axles. I agree with them.

[Brian B-P]

The hyphen in the middle of "Axle-Less" by Timbren is important: Axleless® is a registered trademark for Dallas Smith Corp's suspension product. Dallas Smith Axleless is another independent trailing-arm suspension like the conventional "rubber torsion" systems and like Timbren's Axle-Less. Dallas Smith Axleless uses air springs; Torflex is available with a combined rubber and air spring system (Airflex)

[Brian B-P]

Originally Posted by Jared J

I would call them spindles, not axles. I agree with them.

Okay, then if every company that sells stub axles is misusing the term or I am misunderstanding how they are using it, and an "axle" is a beam joining one hub carrier rigidly to the other, then every independent suspension is "axle less". That makes Timbren right, but far from unique or even unusual.

[Jared J]

Originally Posted by Brian B-P

Okay, then if every company that sells stub axles is misusing the term or I am misunderstanding how they are using it, and an "axle" is a beam joining one hub carrier rigidly to the other, then every independent suspension is "axle less". That makes Timbren right, but far from unique or even unusual.

I have never thought of an ifs vehicle as having a front axle.

[franck2cv]

Originally Posted by Brian B-P

Okay, then if every company that sells stub axles is misusing the term or I am misunderstanding how they are using it, and an "axle" is a beam joining one hub carrier rigidly to the other, then every independent suspension is "axle less". That makes Timbren right, but far from unique or even unusual.

Hmmm... not quite. VW beetles, VW Baywindow buses and Citroen 2cv have front independent suspension joined by a rigid beam. That Beam houses the torsion rods for the Vw's and the steering rack for the Citroen (photo).
There may be other examples I'm not aware of.

[Jared J]

Originally Posted by franck2cv

Hmmm... not quite. VW beetles, VW Baywindow buses and Citroen 2cv have front independent suspension joined by a rigid beam. That Beam houses the torsion rods for the Vw's and the steering rack for the Citroen (photo).
There may be other examples I'm not aware of.

Hmm, not quite to you. If it was joined rigidly, then it wouldn't be independent, now would it?

[franck2cv]

Originally Posted by Jared J

Hmm, not quite to you. If it was joined rigidly, then it wouldn't be independent, now would it?

Getting semantic here ! Liking it!

In those example, the Axles are mounted rigidly to the chassis and even though completely static they are part of the independent suspension design. Both manufacturers refer to those elements as front axle (replacement parts, maintenance etc...).

[Jared J]

Originally Posted by franck2cv

Getting semantic here ! Liking it!

In those example, the Axles are mounted rigidly to the chassis and even though completely static they are part of the independent suspension design. Both manufacturers refer to those elements as front axle (replacement parts, maintenance etc...).

It's not semantics , he said "if an axle is a beam joining one hub carrier rigidlyto the other (fairly close, can't quote both on the phone). If both sides pivot on it, then it's not rigidly joined.

[ruscal]

Is it potata or potato? It's still a tader, or is it a tater?
What ever that tube that houses the torsion element is called is missing on the suspension shown in the original post. It would be a loose terminology to call it an axle, but marketing departments decide these things and the truth gets stretched. Axle-less rolls off the tongue a little better than "tube that houses the torsion element-less". "tube" or "beam" may be more apt?
Russ

[Brian B-P]

Jared has it right. The VW, Citroen, etc have a structural crossmember across the car; they don't have a beam which moves with the wheels (because they are independent), and thus in Jared's use of "axle", they don't have one. Same as a Torflex or other conventional "rubber torsion" suspension.

Similar suspensions have been used by several companies, in both front and rear, both driven and non-driven.

Originally Posted by ruscal

Axle-less rolls off the tongue a little better than "tube that houses the torsion element-less". "tube" or "beam" may be more apt?
Russ

"Crossmember" would be correct, clear, and consistent with normal automotive practice.

Still, my original point is that the Timbren "Axle-Less" may be a fine product but is no more "axle-less" than other designs; if the intention is "crossmember-less", then it has already been mentioned that other brands are also available with separate left and right units without a crossmember.