How to Choose the Correct Ramp Spring for a Trailer

Question:

I notice your competition has a similar spring for 11/2 in shaft . They state theirs has 3912 inch pound of versus your at 2k of torque. Which has the more assist. Thanks

asked by: David

Expert Reply:

A ramp door spring rated for 4k in/lbs of torque is going to offer more assistance than a ramp door spring rated for 2k in/lbs of torque. However, choosing the highest rated door spring available is not in your best interest. If the spring was rated too high then the ramps would more or less have a mind of their own and will be very jerking when lifting and lowering. If the spring was rated too low then it would not offer enough assistance and the ramps would feel very heavy and difficult to lift/lower.

The correct ramp spring for you is going to be based off of factors such as force and defection. If you really wanted to calculate the correct torque for a spring then there is a formula available which I have attached for you below but most of the time, single and tandem axle trailers will use a spring with around 2k in/lbs or torque and larger triple axle trailers will use a spring with around 4k in/lbs or torque.

If you need a spring that offers around 2k in/lbs or torque then we have part # RS16933LH for left hand and part # RS16933RH for right hand.

k=P*M/Deg

P= Force Exerted on Spring (lbs)
M= Movement of Arm (inch)
Deg= Defection (degrees)
k= Spring Constant (in-lbs/Deg)