How to Measure to Calculate Placement of Torsion Axle

Updated 05/14/2025 | Published 11/05/2019

Question:

For small tear, single torsion axle. What should I use in axle placement calculators: center of the wheel or center of the axle? Even this small distance makes difference in my design. Thank you

asked by: Slava

Expert Reply:

I understand how it would be unclear which measurement to use since the center of the axle is not the same as the center of the wheel on a torsion axle.

For a single axle trailer, measure from the center of the spindle (center of wheel) to the trailer tongue. The position of the wheel center relative to the center of gravity will determine the final axle loading as well as the hitch load. This applies for both leaf spring axles, like # e43SR as well as torsion axles, like yours.

expert reply by: Carla M

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Mike J.

5/8/2025

Hi Carla, I want to convert a single axle travel trailer to a tandem axle, my trailer is 16 ft ttl Length can I just space the 2 axles an equal distance from the original centre point,? Thank you. Should the brakes be on the rear axle?

Heather A.

5/14/2025

@MikeJ Great to hear from you Mike, sounds like you’re diving into a pretty cool trailer project! When it comes to adding an extra axle, getting the placement right is key to making sure everything tows safely and smoothly. I can't tell you exactly where to place the axles. You'll want to position the axles so that roughly 10 to 15 percent of the trailer’s total weight ends up on the tongue. Finding that sweet spot can take a little trial and error, so it’s smart to mock up the suspension components first to test positioning before making anything permanent. I have attached a helpful article for you to do some calculating. Also keep in mind that adding a second axle will definitely help with distributing your load better but it won't actually increase the overall weight capacity of the trailer. As for brakes, ideally, both axles should have brakes, especially for safety and legal compliance, depending on your trailer's gross vehicle weight rating and your state's laws. If you are going to only put brakes on one axle, it should be the rear because it helps stabilize the trailer under braking. Let me know what you think!

Helpful Links

faq-where-to-position-trailer-axle.aspx