Bionicon C.Guide V.02 Chain Guide
"The C.Guide V.02 is a great example of simple, elegant design. It's so simple and obvious you can't help but wonder why no one ever thought of it before. Actually, I've been told there was a similar chain guide in the 90s but it was a hook instead of a tubular design like the C.Guide and big hits could still knock the chain loose." - MTBR.com
I was a little hesitant about how well this little chainguide would work, as I am definitely on the more agressive side of things when it comes to all mountain riding. So far after a couple weeks of heavy use on really rough trails, not had a single dropped chain. Something that would happen often on my Rocky Mountain Slayer70 when the trails got rough. It's even held up great when hitting larger jumps and drops at the bike park, so no complaints from me. Just be sure you add a couple links to your chain when you install the Bionicon, otherwise your shifting may suffer. Only slight downside in my opinion is the allen screw that holds the two halves of the guide together is kind of small. Even the manufacturer recommends putting tape or something over it to keep it in place. Surely there's a sturdier option? Regardless, does what it's supposed to quite well, even on rougher trails and larger stunts.
got one on a recommendation from a framebuilder, and it is awesome. much quieter and ever worked with the triple i was initially using.