The aerodynamic obsessives at Zipp have continually impressed us with their inability to leave winning designs well enough alone. The 404 NSW Carbon Clincher Road Wheelset is the latest fruit of their restless tinkering, and it improves on the already impressively improved 404 Firestrike model. These improvements start with a claimed weight that's 65g lighter than the Firestrike equivalent and 135g lighter than the Firecrest. The improvements continue in three other key areas: aerodynamics of course, the freehub, and braking. We'll get to the hub shortly but, this being Zipp, we're inclined to focus first on the rim. We're always ready to welcome any wind taming benefits, but we're actually a little more excited about the improved braking. The rims are equipped with an updated version of Zipp's Showstopper brake track, which enjoyed an impressive debut on the Firestrike 404 but has already been improved for the NSW model. It's still imbued with the same silicon carbide particles, but the direction specific grooves have increased in number and changed in depth. The original Showstopper netted some pretty impressive stopping across all conditions, but Zipp assures us that the new version is even better. The upshot is you can hold speed longer while approaching a corner, braking later and gaining tiny increments of time with each bend or switchback. You can also, you know, stop reliably when obstacles like darting dogs, inattentive motorists, or run off debris on a fast canyon descent make unexpected cameos in your ride. Ok, we now return to the subject you probably expected to be the headline for a new Zipp wheel. The brand's signature Aerodynamic Boundary Layer Control ABLC dimpling returns with a new designation. It's called SawTooth Technology, and it consists of ABLC dimples applied in a single pattern repeated in 12 discrete swathes or nodes across the rim's surface, looking much like the strokes of a paint brush. Zipp's description of SawTooth's eff...