Exhaust Springs 4 Pack Swivel . Apico Factory Racing Exhaust Springs are available as either a stainless standard swivel spring or black finish standard spring. Both types of spring are supplied as a 4-pack. If you’re not too sure why you’d need exhaust springs, it’s simply because a lot of off road motorcycle pipes are not attached directly to the cylinder, rather a flange that is bolted on to the cylinder exhaust port, with a short protruding piece of pipe. The exhaust is slipped over that pipe, and held tight against the cylinder flange with springs, the benefit being that the pipe is less likely to break from vibrations.