Author: Robert K.
Shock cord (also known as bungee cord) utilizes one or more elastic strands covered in a woven sheath to create an ultra-strong, but highly “stretchy” cordage. It can withstand incredible amounts of weight combined with shock and return to its original form, making it a favorite for bungee jumping, but also for securing items to tie-points, as in strapping down luggage on the roof of a car, coarse netting used in pickup truck beds and for securing oddly shaped items on the back of vehicles. As has happened with paracord, however, imitation is the sincerest form of flattery and an invitation for cheap knockoffs. If you're looking to purchase shock cord, avoid these mistakes.
Elongation of a elastic shock cord is expressed as a percentage of its unstretched length; cord rated at 100% can stretch to double its original length. For example, a 24-inch cord with a 100% elongation rating can stretch to 48 inches while the same cord rated at 50% would only stretch to 36 inches. Making sure you purchase cordage that can stretch to your desired length is critical to knowing it can do the job you had in mind. You want to avoid cordage that cannot stretch to your desired length, but also cord that provides too much stretchiness, making a tight strap all but impossible.
Thicker shock cord is usually stronger, but much harder to work with. The thicker the cord, the harder it is too stretch and affix to a secure point. This is particularly true if you buy bulk shock cord; you do not want to have an inventory of shock cord no one can work with.
While very durable, the sheathing of a bungee cord is not indestructible. Depending on the use you put it too, it can become compromised by UV light, abrasions, water saturation, mold, repeated stretching shocks, etc. You want to purchase a cord that is rated for what you will expose it to and will stand up to significant and constant exposure.
You can get bungee cord in almost any color or pattern. Mixing it up color-wise is more than just about personal preferences. Highly colorful bungee cord is also highly visible, making it easier to see. That can come in handy for motorists behind you if you're using it to secure a vehicle trunk or to warn people working around it that it is present.
Using proper shock cord ensures you will be able to secure your load safely and with peace of mind. Not matching the proper cord with the load you want to secure or mismatching the sheath can lead to a compromised load. Follow these guidelines when selecting your shock cord to ensure it will withstand whatever you throw at it.