The segmented bash guard is novel, but it makes sense - the guard always points down when the pedals are in position. To add a second segment; remove the cosmetic threaded lugs on the two remaining spider ends and replace them with chainring nuts.

The lower guide is made of a similar rubber-like substance used for cam-chain guides in auto engines, so it should be quite durable.

The guide's lower shoe pivots on a sturdy, spring-loaded arm.

Shimano's 2013 Saint launch went off at the Sea Otter in front of an enthusiastic crowd, where we noticed a prototype chainguide which breaks a few rules and looks quite promising. The bash guard, which is intended to be an addition to the Saint group is segmented so that riders who favor one foot forward can save some rotating weight and run only one segment on the side of the crankset that faces downwards. Riders who can corner and jump with either foot leading can run two segments. Shimano states the weight of a single-segment guide is 147 grams, which is definitely race worthy.Where most chainguides use a roller on the lower boomerang. Shimano chose a carefully contoured rubber-like guide shoe that articulates on a spring-loaded arm. The net result of the spring-loaded guide shoe is that the chain is supported closer to the chainring and the guide tucks away to safety when bashed by a root or rock.The new guard is not a rough prototype, as the molded rubber shoe and the upper guide mechs are produced in molds, as is the spring-loaded articulating arm. The boomerang fits ISCG-05 mounts and is adjustable to fit 34, 36 and 38-tooth chainrings. Not finalized yet is whether or not the bash guard segments will be produced in separate diameters for each of the three chainring sizes Shimano offers for the Saint crankset.While the new guide is definitely a downhill setup, Shimano says that Saint, XTR, and XT share the same bolt circle, so the new guide, when released, can retrofit to a lighter-weight crankset should one want to assemble a sweet enduro style one-by-ten drivetrain. On that subject, the friction created by the sliding surface of the lower guide is reported to be equal to or less than that of a roller-type guide. The explanation is that the deflection of the chain is less with the Saint guide and there is less resistance when the chain is running at the extreme ends of the cassette. Spinning the crankset on the demo bike, while not a conclusive test, lent credibility to Shimano's claims.Will we be seeing the guide in our LBS anytime soon? Highly unlikely. Shimano's Matt Robertson says that the Saint team wants another year of testing on the World Cup circuit before they give it a thumbs up for production.