The launch of Zipp’s Firecrest rim profile in 2011 changed the way the bicycle industry thought about wheel aerodynamics and now the American firm has launched a technology it believes is equally as revolutionary. The new Zipp 454 NSW carbon clincher utilises an undulating 53/58mm-deep rim to create a wheel which is said to simultaneously reduce both aerodynamic drag and improve crosswind stability.
Stability is the key as far as the 454 NSW is concerned. Aero wheel manufacturers have long battled to marry high aerodynamic efficiency with low side force (or, in other words, the stability of the wheel in crosswinds) but Zipp say the 454 NSW is the first wheelset to truly bring the two together.
The combination of aerodynamic efficiency and stability is what Zipp call aero balance and the 454 NSW comes in with a claim as the “highest performing wheelset ever realised, with both aero-drag reduction and reduced side force at all wind yaw angles.”
Stability comes from the undulating Sawtooth shape which, combined with the rim’s HexFin dimple pattern, is said to improve handling in gusting wind conditions by helping to keep airflow attached to the rim, rather than detaching and creating additional turbulence.