I think the Tri-Ad is a Cold Steel design and Spyderco can't use it. Could be wrong. The back lock on the Sage4 has a post on the tang that travels in a groove in each liner and when the blade is locked the post rests against the liner at the end of the groove. This (I think) is supposed to reduce or eliminated vertical blade play developing over time which back locks are prone to by design. That's my understanding so again I could be wrong. The post probably has a similar effect on the knife as the stop pin in the Tri-ad lock. It may transfer force against the edge when cutting to more of the handle (both liners) than just against the lock bar. That's me thinking, NOT anything I've read from Spyderco or anyone else. My Sage4 doesn't have any blade play, horizontal or vertical at all which makes me very happy. I hate blade play in folding knives.
Originally Posted by David Lowry
MY CURRENT EDC
Sage4: Now with black linen (micarta) scales, stonewashed blade and bolsters
Manbug (G-10): Now has camo-desert kirinite scales, ZDP-189 blade ground to a Jester-like spine, stonewashed blade and bolsters
Fenix LD01 (single AAA flashlight) clips to Manbug FOB