How far should the Electric Bungy stretch?

Good quality Electric Bungy can stretch to twice its relaxed state. This is when the outer sleeve is relaxed and the rubber can stretch to its maximum capacity. But you would not rev your engine to the limit if you wanted the engine to last, same with the rubber core. 

This is not always advised, as pushing the rubber to its limit over time will cause it to lose its elasticity. So, we place a polyester sleeve over it to reduce the rubber reaching it's maximum, then place polyethylene over that to ensure that it can stretch to 50 to 55% extra from its relaxed state. This allows the rubber to continue to have the elasticity for many seasons to come. By having the two sleeves over the rubber, it reduces the rubber being exposed when stretched (the grin), thus preventing the rubber from deteriorating over time.

When making a gate, we advise our clients to use 4m on a 5m gate space, allowing 25% stretch for the Bungy and still having some give in the product. The double sleeve on the Electric Bungy allows for greater durability.