Test Zipp 858 NSW wheels for time trials and triathlons

Last May, Zipp unveiled the latest version of its 858 NSW, aerodynamic wheels designed for those battling against the clock on route or in triathlon. Now even lighter despite their impressive profile, they are designed to offer tangible performance gains in the real world. We were able to test them. tester at different intensities on a time trial bike, for results that will blow your mind.

By Guillaume Judas – Photos: ©3bikes.fr

Since his birth almost 40 years ago, The Zipp brand has always invested in researching optimal aerodynamics as the primary driver of performance.And even today, the latest evolution of the 858 NSW and the Super-9 (which we'll discuss again in a few days) demonstrates just how crucial wheel profile is in the quest to shave off seconds, especially when it comes to battling the clock alone, whether in a time trial or a middle- to long-distance triathlon. But like many frame and bike brands now limited in their development by UCI regulations or available technologies, Zipp has recently understood the value of working on the overall real-life effectiveness of the proposed system, that is to say on the route with all the variations in terrain, elevation, and surface that one is likely to encounter. According to Zipp, it is a " A balanced strategy to overcome the four obstacles to gaining and maintaining speed while riding: wind resistance, gravity, rolling resistance, and vibrations. ».

The American brand adopted this philosophy with the 303 S and 303 Firecrest, then the 353 NSW, and more recently with the 454 NSW and 404 Firecrest, before extending it even to the most specialized wheels in the range, designed solely for time trials: the 808 Firecrest, 858 NSW, and Super-9. All these new-generation Zipp wheels are lighter and have wider rims for the worldtagLarger tires are only available for disc brakes and with hookless rims, in order to to best combine aerodynamics, comfort and versatility on almost all terrains.

Faster on all terrains

The 858 NSWs therefore benefit from this philosophy, even if they are very specific and designed for pure time trial and triathlon useThe very high profile of the rims makes them unusable in peloton races, according to the new UCI regulations from January 1, 2026 (which limit rim height to a maximum of 65 mm). Nevertheless, with their signature sawtooth profile, varying from 82 to 85 mm, the 858 NSW rims are designed to optimally combine a highly aerodynamic profile with crosswind stability equivalent to lower-profile rims.

The 23mm internal and 27mm external widths, optimized for 700x28 tires, also contribute to significantly improved stability compared to the previous 858 NSW, despite a slightly shallower rim. According to Zipp, this width reduces tire deformation and lowers rolling resistance, resulting in a more stable ride.tagan additional advantage over competing options with 23 or 25 section tires, supposedly more aerodynamically efficient. Moreover, thanks to the hookless technology, The wider tire bead, combined with the external shape of the rim, provides a smoother and more aerodynamic transition between the tire sidewalls and the wheel sidewalls..

According to Zipp, it also contains an advancetage in the area of ​​comfort : " A wider bead interface allows the use of a wider tire, and therefore lower pressure. This improves overall efficiency, reduces rider fatigue, and provides better grip on uneven terrain. "An essential characteristic for long-distance triathletes, who must run a half or full marathon after the cycling leg."

In terms of constraints, the 858 NSW requires tubeless tires compatible with a montagHookless tires, with a minimum width of 28 mm and a maximum width of 35 mm (28 mm recommended). You will find the list of compatible tires. on this table provided by Zipp.

While the brand tries to optimize wheel performance in all areas, it continues to rely on meticulously designed aerodynamics down to the smallest detail, such as the famous honeycomb pattern on the rims (golf ball style) or logos printed directly, in order to promote control of the airflow around the wheel.

But above all, Zipp offers a particularly lightweight solution with this brand-new version of the 858 NSW equipped with the new ZR1 SL hubs. Weighing in at Only 1500g for the pair of wheelsThe 858s prove to be particularly versatile on timed courses with elevation changes.

Hubs that finally live up to expectations

While Zipp has been a leading wheel brand since 1988, the same cannot be said for the hubs used until these latest generations. Play, unreliable bearings, faulty freehub bodies… problems were numerous, even on the highest-end models. These issues finally seem to be completely resolved with The new ZR1 SL hubs are lightweight, high-performance, and finally, very reliable.as we can see on a pair of 353 NSW wheels with which we have been driving for several thousand kilometers in all weather conditions.

Weighing 304 g (per pair) and ceramic bearingsThey are lighter than the previous model, and with a 66-point engagement freewheel, responsiveness is immediate at the slightest acceleration. Note that the spoke anchoring is conventional (20 front and rear), allowing the use of non-specific steel spokes on the 858 NSW. A fronttagundeniable for maintenance, although we would have appreciated the use of even lighter carbon spokes, which are increasingly found among the competition for wheels in this price range.

Lighter, more versatile

On routeThe very reasonable weight of the 858 NSW compared to other highly aerodynamic wheels with an equivalent rim height is surprising. On a time trial bike, you feel more responsiveness, more ease, when tackling gentle inclines in a seated position, or when standing up to climb a steeper slope. The 858 NSWs remain very rigid and deform very little under stress. But The 300g saved compared to most competing models proves remarkably effective on rough terrain or with frequent restarts.This also represents a significant energy saving over long journeys.

This weight gain does not equate to a decrease in inertia at high speed. Once underway, the 858 NSWs maintain an excellent cruising speed., barely less than that found with a lenticular wheel like the Zipp Super-9, which we will discuss later.

On a time trial bike, you certainly feel the high susceptibility to crosswinds inherent in this type of wheel. But In terms of feel, it's very similar to the Roval CLX 64. For those who know, these are wheels that are no longer in the catalogue but are 20 mm lower in height, and weigh about a hundred grams more.

With a bicycle routeNevertheless, we end up with a somewhat anachronistic set, which is no longer accepted by UCI regulations anyway. Although particularly lightweight, The 858s remain relatively demanding if you stick to a simple ride at an average speed of 30 or 32 km/h.They are rigid and require a pilot.tage of the bike quite sharp, rather unusual with a classic bike.

In accordance with Zipp's recommendations for rims without hooks, we kept the pressure below 5 bar throughout our outings test with the 858 NSWThat's 2 bar less than with 25-inch tires. A world of difference. Not only the gain in comfort and traction on the routeThe difference with a poor coating is noticeable., but moreover, the almost perfect shape of the tire on the rim caused no sensation of crushing during out-of-the-saddle riding or hard accelerations with a very high gear ratio.

Ideal for long and challenging triathlons

For time trials of 15 to 20 km, we prefer a combination of a front wheel and a Super-9 rear wheel to the 858 NSW for raw performance. However, The 858 wheels seem particularly well-suited to challenging triathlons with significant distance and elevation gain, where they stand out as arguably the most versatile aerodynamic wheels on the market thanks to their light weight and comfort.The price remains very high, even though the wheels are, fortunately, guaranteed for life.

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