Shock Cord

[hang10]

REI store or online

[tdickenson]

Does it weaken shock cord to be stretched for long periods? For example I have had my hammock hung up in my basement for the last week with the UQ attached below. The shock cord is under some load, although less than when I am in the hammock.

Yes, the rubber in the shock cord will show a permanent set if moderate loads are applied for a long time. The same happens under compression, so you don't want to leave the cord with any tight knots.

Does shock cord approach a yield point? IOW, if you stretch it too much the material yields and loses some of its stretch.

Stretch rubber too much and the modulus increases, so it is more likely to snap than yield.

Does it lose its stretch in very cold temperatures?

Good question. The key property is "glass transition temperature", where the rubber becomes leathery, and this varies significantly between different rubbers. I am putting a sample of the shock cord I use in the freezer right now.....