Advertisement

Sign up for our newsletter

Advertisement

Zipp overhauls race performance wheelsets: New 404 Firecrest and 454 NSW designs

22 Jun 2021
Verdict:

Zipp says the new wheels are wider, lighter, faster, cheaper and greener

Following on from the revolutionary modifications to its 353 NSW, 303 Firecrest and 303 S wheels earlier this year, Zipp has now applied a similar design rationale to the 404 Firecrest and 454 NSW wheels in order to update them.

As such, the wheelsets are now 4mm wider internally than their predecessors, hookless and disc-only. Zipps says the 404 Firecrest wheelset is 370g lighter, 4 watts faster and £720 cheaper, while the 454 NSW is more than 450g lighter, 10 watts faster and £370 cheaper.

The deeper wheels are focussed more towards race performance so the changes differ slightly to those made to the shallower wheels, but are based around the same tenets that informed their redesign earlier this year.

Zipp says the overarching philosophy that has governed the design of its latest generation wheels is called ‘Total System Efficiency’. The system contains four factors – wind resistance, gravity, rolling resistance and vibrational losses – that define speed to varying degrees depending on riding discipline.

To give an example, for gravel riding Zipp says it has found those four factors to hold somewhat equal sway over a rider’s given speed. For road racing however – the discipline these new wheels primarily cater for – wind resistance occupies a much bigger part of the pie, accounting for roughly two thirds of what governs a rider’s speed.

 

Either way though, Zipp says all four areas must be balanced appropriately to enable the fastest design.

Zipp says it has looked beyond pure aerodynamic efficiency because wheel design has reached a point where getting further drag reductions comes at an expense elsewhere that may actually result in the wheel being slower overall.

‘Therefore we are focussing on becoming faster, not more aero,’ says Zipp’s Daniel Lategan.

The importance of going hookless

Perhaps the defining feature of Zipp’s latest generation wheelsets is the move to a hookless rim design. Hookless rims do away with the curled over ‘hook’ portion of the rim side wall that provides a physical guard to a tyre blowing off a rim. Instead the rim wall extends straight up from the rim bed.

 

The feature enables distinct design advantages and looks to be the way rim design is headed, but is still somewhat controversial. There is some confusion about official approval and rim/tyre compatibility, causing some to lack faith in a hookless rim’s ability to retain a tyre.

Zipp seems confident that this is simply a transitional period and hookless will soon become the norm, with tyre compatibility becoming a non-issue. The brand states that hookless rims are approved by the ETRTO and ISO, and that Zipp wheels are fully compliant with each organisation’s standards.

Zipp says that hookless rims are just as safe as traditional hooked rims in terms of tyre retention and in performance terms, hold several clear advantages over hooked rims.

The inherent shape of hookless rims creates a smoother transition between tyre and rim, improving airflow and reducing drag. Zipp says the simpler rim shape allows for better resin distribution too, making the rims stronger and lighter as well as more aero, and as the shape is less complicated to manufacture, ‘hard’ tooling can be used to make rim channels to tighter tolerances.

This is less costly, generating savings that Zipp says are passed on to the consumer, and it also produces less waste because the bladders used in the ‘soft’ tooling of hooked rims have to be disposed of.

All in all, the brand makes a compelling case for hookless being the future of wheel design and the new products appear to back up the theory in practice pretty emphatically.

Lategan explains that Zipp commissioned airflow experts AeroLab to use its external aero sensor (a sophisticated prong that extends off the front of a bike’s bars) to vindicate the wheels' design in the real world.

 

Zipps claims that thanks to appropriately addressing all four ‘barriers to speed’ – weight, drag, rolling resistance and vibrational losses – in the new 404 Firecrest and 454 NSW wheel design, an 85kg rider/bike system weight travelling at 40kmh on real roads stands to save four watts using the 404 Firecrests and 10 watts using the 454 NSW.

454 NSW

The 454 NSW might not have been in Zipp’s range as long as the venerable 404 but is an equally prominent wheelset, being the first to introduce the brand’s variable depth rim profile back in 2018.

Zipp says the ‘HyperFoil nodes’ of the variable shape work in tandem with the rim’s ‘HexFin ABLC’ dimple pattern to make the wheels more stable in crosswinds compared to traditionally shaped rims.

 

The latest 454 NSW continues to use the 53-58mm rim depth, but uses the weight-saving potential of hookless design and better carbon scheduling to impressive effect. The new wheels save 250g over last year’s 454 NSWs, and now weigh just 1,385g per pair.

That is despite the rims’ internal dimension growing wider by 4mm, now measuring 23mm. While that is considered wide by modern standards, for best ‘Total System Efficiency’ Zipp recommends pairing the rim with 25mm tubeless tyres.

According to the brand, 25mm tyres paired with this rim architecture create the smoothest tyre-rim transition, encouraging better laminar flow across the wheel and reducing drag.

The inverted ‘U’ shape given to 25mm tyres on this rim apparently also optimises tyre casing support, meaning lower pressures can be used to improve rolling resistance and vibrational losses too. Zipp says tyre pressure is a vital factor in the equation to go faster, so has devised a comprehensive calculator to work out any rider’s given ideal setup.

Thus in this way, all four ‘barriers to speed’ have been balanced appropriately for the road race riding environment these wheels are designed to be used in, says Zipp. They add in a new version of Zipp's Cognition hubset too.

Their price is still pretty exclusive at £3,200 but has at least been cut by £370 over the previous generation of wheels.

404 Firecrest

The Zipp 404 design has quite the heritage: it is the most direct descendent of Zipp’s first carbon wheel, the 400, which was released back in 1990.

 

For MY22 the wheel takes one of the largest single steps forward in design in its long history. Its depth stays at 58mm but Zipp says the wheelset is a considerable 370g lighter than the previous generation, coming in at 1,450g a set.

The rims’ width matches the 454 NSW at 23mm internally, and use the same 25mm tyre recommendation for best performance.

An equally important change is one to the 404 Firecrest’s price – despite the wheelset’s competitive new performance stats, Zipp has cut the price of the wheels by £720, from £2,320 to £1,600.

858 NSW

The rim of the deepest spoked wheel Zipp offers remains the same this year, meaning it stays fairly narrow at 19mm internally and uses hooked side walls, however the the 858 NSW shares a new hubset with the updated 454 NSW wheel.

 

Zipp’s Cognition hubset uses a revised version of its ‘Axial Clutch’ technology. Essentially the freehub mechanism has been simplified making it lighter, promoting ease of maintenance and durability and lowering friction. The freehub’s points of engagement have been upped too, from 36 to 54.

The 858 NSW will cost £3,930 this year.

All three new wheel designs are available immediately and benefit from Zipp's lifetime warranty. It is a guarantee that aims to offer peace of mind to customers with a ‘no quibble’ (providing the product was being used for its intended purpose) free of charge replacement scheme for damaged products.

Read more about: