How to Determine Required Capacity of Trailer Ramp Torsion Spring

Updated 07/26/2017 | Published 07/25/2017

Question:

Inquiry about part #CB250D96SHD. I have a ramp door that TOTAL weight of ramp door is 260 lbs. It is hung on 5 hinges, which should take half the weight off the door, if my thinking is correct. Will this spring lift this door, and how long are the cables that come with this unit? Thank you.

asked by: Brian K

Expert Reply:

On a hinged trailer ramp the hinges will carry a varying portion of the ramp weight depending on the ramp's position. When fully opened/extended the torsion spring will actually be holding more of the ramp's weight that when it is almost fully raised. In the fully vertical position more of the ramp weight is on the hinges since the ramp will be more directly over them.

The M-3 Enclosed Trailer Ramp Spring # CB250D96SHD can lift 250-lbs of ramp weight. You can use a scale to weigh your ramp if necessary. With the ramp installed on the hinges lower it fully until it contacts the scale. That is the weight the spring needs to be able to handle.

My technical contact confirmed each cable is 150-inches long.

The installation instructions for this product are recommended for individuals who have experience winding torsion springs. If you have not worked with a torsion spring system before, we recommend contacting a local garage door company to install this system.

expert reply by: Adam R