So the difference between a graphite / carbon fiber bike versus a plastic bike is obviously very noticeable. But what about ultra lightweight bottle cages? A high quality plastic one (if there is such a thing), built with weight reduction in mind, it being built with the minimal amount, just enough to keep the bottle in the spot you want it to be in. Then one made with the same thought process in mind, but out of graphite. A buddy of mine bought a bike, he's a camel and doesn't drink water on trips no matter how long, so he's offering to sell me the bottle cage, however we cannot tell if it's plastic or graphite. Me, just buying a Cannondale Jekyll MX and having also a Cannondale Scalpel, I really would like this to be graphite, and I also don't want to offer a friend of mine 30 bucks for a plastic one, or give him 5 dollars for a graphite one. It's painted black, even the mounting holes still have paint in them so I can't tell the material by looking at it really.
This may be a stupid simple answer for some of you, I hope it is. I understand the difference in sound of a walmart plastic bottle cage and graphite, but my Scalpel came with a plastic cage and it sounded like it was graphite, went about a year thinking it was until I broke it, then I saw the break and was like "oh, it was plastic..." So I'm looking for non-destructive testing. I heard using a lighter could get my answer, if it gets soft and you can bend it then it's plastic, but I don't want to damage his property.