One of the most important parts of any trampoline are the springs as they determine the quality of the bounce which is why you purchased the trampoline in the first place.
The quality of the bounce is determined by two main factors:
1. The more springs per unit the better the bounce. 2. The longer the spring the better the bounce. Things to Consider
You should only purchase trampoline springs that are made from high density galvanised steel to help protect them from rust.
Springs under normal use should last a long time. You should not see a broken or stretched out string on a quality trampoline.
Insure that the springs are not exposed. They should be covered by a spring cover. The cover will act as a shield from weathering and keep the user safe.
DDI Sports and fun spot sell high quality trampoline springs that meet all the right requirements.
It is not recomended that you purchase a springless trampoline. Elastic trampolines are less bouncy. Also some springless trampolines can cause injury to the knees upon landing due to a twisting effect caused by the way the elastic stretches. If you are going to purchase a springless trampoline consider a water trampoline. These can be great fun and are relatively safe.