1. Marvin Torwalt
    March 25, 2019 @ 1:33 PM

    I have built well over a dozen trailers in the past 50 or so years and have used several spring lengths and sizes. I built two trailers using rear light truck springs, one a single axle and the other a tandem. Both trailers were built with smooth ride in mind. The single axle is a 6 x 16 enclosed trailer with outboard wheels and was built for moving equipment for sound re-enforcement. I just kept adding leaves to the springs ’til I got the ride I wanted and with shocks added it has surpassed my expectations for ride. Even empty it is exceptionally smooth. The 8 x 20 tandem was built as a mobile stage to be used at outdoor shows and also in parades where music cds were played. I set the axles quite close together which meant I had to overlap the springs without equalization. I accomplished this by turning the springs slightly on the axle mounts ’til the rear cleared the front springs. The rear axle has heavy duty shocks added to reduce sway and bounce. After 20 years of hauling all kinds of loads it has given absolutely no trouble and the looked for results were achieved. With the length of the springs and the built in clearance to the frame equalization has not been a factor. I’ve often wondered why all light duty trailer springs are built so short. With heavy trailers I can certainly see the advantage of the shorter springs.


  2. Monica Davenport
    August 13, 2020 @ 12:09 PM

    I am entirely of the same opinion when it comes to spring length. The longer you can get, the smoother the ride and the less stress on the main beams.
    I built a 4×8 trailer back in 1987 using the front drop axle of a 1970 Chevy van (rated at 3500#) combined with a set of 48 inch long leaf springs. The ride is absolutely fabulous compared to every other trailer which I either purchased or built using standard trailer springs.
    The trailer is somewhat over built with an empty weight of 950 pounds but even without any cargo, it hardly bounces at all going over large bumps and potholes in the road.
    The suspension has a long travel but can still accommodate loads of 3000 pounds before the springs flattens out. Truly remarkable!!!
    But most practical of all is when it comes to moving delicate furniture made with glass components, the thing is so smooth that you don’t notice hardly any shocks or vibrations transmitted to the items being transported on normal road conditions with bumps and holes here and there.
    We can’t use any other trailer with shorter springs for this type of use unless we either deflate the tires significantly beforehand or add at least a half ton of weight inside the trailer so that the tiny leaf springs (approx. 25 inches in length) don’t send the trailer bouncing all over the place at the first bump on the road smashing the precious cargo.
    Unfortunately, this makes me the most popular gal in town on July 1st of every year when everyone scrambles on moving day ….. or any other moving day for that matter.
    I should have know better.
    The final word is “the longer the better” when it comes to leaf springs.
    Trailer manufacturers should rethink their strategy and offer much longer springs for single axle trailers.
    Much smoother ride without affecting the payload capacity. True they are heavier (contain more steel) and cost more but the benefits are amazing and well worth it.
    You can look in scrapyards and get long truck springs. Remove or add blades to adjust the springs to match the size of your axle and you’ll have the best trailer possible.
    My trailer is 33 years old and still going strong, enduring the most diverse set of tasks imaginable.
    Hauling 3000 pounds of tiles or a large china doll it does it all.


    • Frankie Stone
      December 9, 2020 @ 1:35 PM

      I’m curious where you procured the 48 inch leaf spring for your trailer? I’ve been searching the internet and, so far, have had no luck. Thank you.


      • Mechanic
        December 9, 2020 @ 8:02 PM

        Those are usually automotive, like off an old truck, not trailer specific.


  3. Gary Gray
    August 13, 2020 @ 4:09 PM

    On the nomenclature above regarding the spring lengths, is that length before you put weight on them or after its setting on its feet ? The reason i ask is I have a Stellar toy hauler triple with 6k axles… I have one broken spring and need to just do the rest at this point…. the springs are a 4 stack… under pressure they are 26″ long…. relaxed their 25 1/4.

    all my measurements to the schematic up top says it will fit 26 inch springs…. do I go with a 6 stack 26 or a 4 stack 25 1/8 ?

    I guess what really bothers me when reading everywhere… I cant find what sag measurement is once its on its feet…


    • Mechanic
      August 13, 2020 @ 5:44 PM

      I believe the measurement is static, unloaded. I would ask before you buy, and if possible, take one to the shop when you order them. Yes, I know it’s not as easy as buying online, but it might avert a problem. Other option, look at etrailer.com. They usually have drawings with their products, and a video to explain them.


  4. Dennis batista
    August 20, 2020 @ 7:56 PM

    Hi a question… I want to build a dump trailer 2 meter wide and 4 meter long… I’m gonna put a double leaf springs suspension ( so 4 wheels).
    My question is: How do I know where to weld the equalizer? What is the som for that? How do I get the measurement? From the back of the trailer to the tongue where it hook to the ball of the truck, or what? The dump will be 2 meter wide and 4 long but to the tongue will be another 1 meter and a half…. Can you help me out? Or sent me a link that explains that good. Thank you.


    • Mechanic
      August 21, 2020 @ 2:38 PM

      I’m not sure what you mean by equalizer … I’m guessing you mean the equalizing rocker that attaches the front and back axle springs? If so, then that is the “axle position”. When using multiple axles, the “axle position” is the center between the front and rear axles. Please see our article “Where Does The Axle Go?” which gives the equations to figure that out. Good luck with your project.


    • Nicolas Boren
      January 27, 2021 @ 2:27 PM

      I’ve built a few trailers and I use a scale hanging from an engine hoist and a piece of pipe under the trailer to roll the trailer on until I have less than 300 lb of tongue weight. Wherever the pipe ends up under the trailer is the fulcrum where the equalizer for a tandem axle will go or the axle Centerline for a single axle. Its best to build a trailer to carry most of the load well-balanced with very little load transferred to the truck. Assuming you’re pulling it with a single rear axle truck.


  5. Hjalmar Eysteinsson
    September 8, 2020 @ 7:22 AM

    Looking for a single leaf spring 112 cm long (between eyes) 60 mm in with and 10 mm in thickness. It is for a 500 kg trailer. Used on a rough roads. Could send a photo. What is the closest that you can offer?


    • Mechanic
      September 8, 2020 @ 8:14 AM

      Thank you for the note. I’m sorry, we do not sell parts, only plans. Good luck finding your needed pieces.


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