16 Comments

  1. Jose G Garcia
    October 12, 2017 @ 8:42 PM

    I vote aluminum all the way, wish the axles were aluminum tubing as well. Galvanized is good but still rusts away in time.

    Reply

  2. Clarence Alexander
    July 19, 2018 @ 6:56 AM

    I have doubts about the illustration for the Double Eye Leaf Spring being correct. Usually DE Leafs are used on twin axles with a rocker bracket in between to share the load between the 2 leafs. The way it is shown will cause an extremely high resistance to flexing under load. For the indicated single axle application a Single Eye with Slipper may be better.
    Now you will have to re-argue your case and redo the FEA.

    Reply

    • The Mechanic
      July 19, 2018 @ 7:30 AM

      Excellent observation. I wondered who would point that out first. Congrats! What you don’t see are the FEA constraints allowing the back bracket to slide so it does not bind (or “high resistance to flexing”) effectively making it a slipper as you mention. It simplifies the FEA because we’re not trying to study the spring or mechanism, only forces on the frame. You are right, the analysis is not perfect, but it’s good enough to highlight the point. Thanks for reading.

      Reply

  3. Roni Sumich
    August 4, 2018 @ 10:53 AM

    Looking to order a goose neck 20 ft 7000 lbs axles. Trying to decide what axle to use. The trailer will be loaded to the max 11,000 lbs evenly loaded over the length of the trailer. Was leaning to a torsion axle but now am more confused if it will be the best choice. Thanks for the article it has great info. Just not sure which is the best way to go, any advise would be appreciated.

    Reply

    • The Mechanic
      August 13, 2018 @ 8:32 AM

      Hey thanks for the question. The only successful multi-torsion axles I have seen are light loads. They don’t share the load, so one axle is always more loaded than the other, and I have heard terrible stories about tire failures, etc.. I would much rather see springs with some rubber damping for some of the effect, but still have full load sharing. I like torsion axles a lot for the right application — not so much here. Good luck with your project.

      Reply

  4. Trix Gaimo
    August 19, 2018 @ 8:37 PM

    Educational article. I plan to build a trailer for a 20-footer shipping container van (about 3,500 kg) which will be modified into a living space (tiny house). What do you recommend, a spring or torsion type? Thanks.

    Reply

    • The Mechanic
      August 22, 2018 @ 10:14 AM

      For that weight, I’d do a tandem set of axles using leaf springs. Good luck with your project!

      Reply

  5. Arnie
    October 19, 2018 @ 10:29 PM

    Hi. I own 2 different Haulmarks Enclosed trailers a 24 foot and a 30 foot and both have torsion axles. I guess they feel they are ok.

    Reply

  6. Will
    February 1, 2019 @ 12:02 PM

    Very nice write up.I’m looking for an enclosed trailer to haul my race bike around(425lbs). With the bike and all the gear, I would go on the high end and say I’ll have around 1200lbs. of cargo added to the weight of whatever trailer I buy. I will be pulling it with a 2013 GMC Sierra 1500 SLT All terrain Z71. It has the tow package and 6speed tranny. I live near Philly, PA. So the roads do get salty, but I don’t plan on using it in the winter. Or very little if at all. It will have to be stored outside as well. I would also like to keep the price down on my purchase. My question(s) is, what brand would you get? I like the idea of a 7×12 v nose tandem axle. I don’t want the low hauler, because while at the track I would like to be able to move around inside without having to croutch the whole time. I’m curious as to what you would get. Steel box frame or aluminum, leaf springs or torision, etc.? Also, the trailer will be driven mainly at highway speeds. Thank you for your time and help.

    Reply

    • The Mechanic
      February 2, 2019 @ 4:46 AM

      There is a lot in those questions. First, it sounds like you need something at 3000# – 3500# capacity. That will carry what you mention, and pull easily by your vehicle. Second, the capacity means you don’t need tandem axles. You could, but it’s overkill and though tandems offer a nice ride, in this case it will likely be over capacity giving it a rougher ride. A single will do fine. Third, I don’t know all the brands well enough to recommend one. Do your research. Fourth, Aluminum or Steel is more of a budget question. Aluminum frame will likely cost 2X or 3X, but definitely get aluminum or plastic or fiberglass sides and top. Fifth, for a single axle at 3500# or less, Torsion is a good, but make sure they have strengthened the frame around the axle mounting — otherwise, get springs. https://mechanicalelements.com/mounting-trailer-axle-springs/ If you do go tandem, don’t do Torsion. See above. Hope that helps.

      Reply

  7. Jason
    July 13, 2019 @ 7:28 PM

    I’m a noob but what about 5th wheels using double and triple torflex and moryde axles? They weigh around 20klbs.

    Reply

  8. Jason
    July 26, 2019 @ 11:09 PM

    Would like to hear your input on above comment I asked. I approached The RV Factory and they said it’s no worries with thier 12″ I-Beam main frame with tons of support and cross members. AKA super beef frame, not typical RV… Apparently Moryde is coming out with a new level Independent Suspension air ride upgrade.

    Reply

    • The Mechanic
      July 27, 2019 @ 6:50 PM

      Torsions are fine, and the Moryde is a different version of rubber suspension. See also the Axle-less suspension. https://mechanicalelements.com/axle-less-trailer-suspension/ We’ve written about these on the site in one place or another. There’s nothing wrong with any of these IF the trailer is designed for them — and that’s not too hard. The problem comes when you put them in Tandem or (worse) triple. They don’t “load share”. That means one axle or one wheel carries significantly more load than the others at one point or another — because all roads and surfaces are not smooth and level. When you significantly overload one, failures happen. I don’t know why people continue to propagate the lies about how wonderful these are in pairs. “Independent Suspension” sounds so good, but it misses the point. Read this: https://www.synthx.com/how-do-you-know-who-to-believe/ One of these days I need to finish editing the video showing the problems these give.

      Reply

    • The Mechanic
      July 27, 2019 @ 6:54 PM

      Oh, and it does not matter if we’re talking bumper hitch or 5th-wheel. Stay tuned, I’ll post some technical info here one of these days when I get some time.

      Reply

    • JOHN SANDERS
      October 6, 2019 @ 8:24 AM

      I have an airstream with double torsion axles no problem for almost 40 years.

      Reply

  9. Jason
    August 2, 2019 @ 3:47 PM

    Yea I read your stuff and findings, makes perfect sense. I worked at a bearing Co. for years and took numerous classes so have general understanding of stuff like this. So you are saying then The RV Factory who makes the Luxe line (150k 5th wheels) are making mistake using the Torflex and Moryde IS axles? They don’t have any single axles, only double and triple. I am looking at their 48ft toy hauler so a triple obviously.

    Reply

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