dual ring chain guide. simple, effective. single pivot+longer travel = (sometimes) flopping/dropping/noisy chain action on ugly trails. this stops that, and still lets me run both front rings without having to resort to a full on chain guide. look around, you'll actually see them on quite a few bikes in the 6" or more travel range. adds minimal weight, does the job beautifully.

that, and the gravity droppper post have been the two single best additions to this ride.

right at 36# in that picture. whenever the new fork gets in, that'll shed at minimum another half pound. pedals up on the slow side, but it's very worth it coming back down stuff, and just in general on ugly trails.