If your chair feels a bit uncomfortable, it might be the tension springs that need attention. Replacing tension springs are very easy to do.
Measure your chair frame and select the right size springs. When measuring tension springs, measure from the inside of one hook to the inside of the other. This helps you get the right size for your chair. Make them about 10% smaller than the frame for a regular fit. If you want the seat softer, make the springs a little longer.
If you are dealing with a diamond (or similar) spring pattern take a photo before you remove the springs, and label and measure each one.Â
Hook the tension springs onto the screw eyes, bracket or trunk plates that attached to the chair frame. If needed, trunk plates to make the tension springs more secure. These plates are sold separately and add extra stability to your chair.
For seats with stapled foam and fabric, cover the tension springs with hessian for a tight feel. If your seat has loose cushions, use quilted lining on the tension springs for a nicer look.