Originally Posted by fortyseven

plastic for sure!
metal has a tendency to bend out of shape and then weakens on the bend.
I broke a metal clip bombing down the north side of Franklin (in SF) many years ago, used plastic ever since.
plastic will break too, but the life expectancy is longer. you gotta keep an eye on your clips, straps and chain (especially if you don't have breaks) they'll let you know before they fail.