Test new Zipp 353 NSW with pressure sensor

The new Zipp 353 NSW wheels have slightly lower rim heights than the previous model and benefit from a revolutionary pressure sensor.

Zipp has just unveiled a new version of its 353 NSW wheels, a high-end model designed for route and rough and uneven terrain. With advanced technologies like the pressure monitoring system AXS, hookless rims, and ceramic bearings combine lightweight, aerodynamic, and robust wheels. But are they worth their hefty price tag? We already have them. testspread over several hundred kilometers.

By Guillaume Judas – Photos: ©3bikes.fr

The 353 Zipp 2025 NSW retains a very clear family resemblance with the previous model, that we had testand in 2023, with the famous profile called Sawtooth inspired by the fins of humpback whales. But they adopt a rim height varying between 35 and 40 mm, against 42 and 46 mm previously. A "wave" shaped profile initiated by Zipp and now taken up by many manufacturers, as we can see with the Fulcrum Sharq, Sonic Ultra, or the SH Race Aero WaveThis design is intended to improve aerodynamics and stability in crosswinds, in combination with special patterns on the rims, nodules called Hyperfoil and dimples called HexFin ABLC.

By lowering the rim height on these new 353 NSWs, Zipp sought to increase their versatility while differentiating them more clearly from the 454 NSW, which have a height of 53/58 mm. While visually this lower profile gives the bike a more slender look, the hookless rim continues to have an internal width of 25 mm, which gives it ideal compatibility with tubeless tires from 29 to 35 mm. With tires Goodyear VectorR Z30 NSW in 30 mm as part of this test, the whole is in any case perfectly coherent and does not form a balloon detrimental to the coefficient of penetration in the air.

We know the advantagestagThe advantages and disadvantages of the hookless system: weight savings, but limited tire compatibility, and above all, a maximum authorized pressure of 5 bar, which nevertheless offers greater comfort and reduced rolling resistance in certain conditions. We will come back to this later in the article.

Measured lightness

Among the new features brought to the 353 NSW, Zipp announces new carbon fiber layout that would increase impact resistance by 16%, thus strengthening their durability. But be careful: the 353 NSW are not approved for Gravel riding.

They havea new ZR1 SL hub, 30 g lighter than its predecessor, which (finally!) offers ceramic bearings and 66 engagement points for increased responsiveness. Also note that the Axial Clutch V2 mechanism reduces friction when freewheeling, also improving efficiency.

With only 1 307 g, AXS sensor, rim tape and valves included, The 353 NSW are Zipp's lightest tubeless wheelsTheir weight is almost identical to the previous model, but they incorporate the famous pressure sensor, which alone weighs around twenty grams.

However, it is necessary to put this displayed weight into perspective by associating it with that of the 30 mm tubeless tires and the preventive liquid. The Goodyears weigh a little more than 300 g, and it is necessary to count around fifty grams for the liquid inserted in the tire. Thus, I was able to compare the weight of the mounted wheelset, with cassette and discs (in Sram Force), with a pair of first generation Roval Rapide CLX clincher wheels, with cassette and discs (Shimano Ultegra 11 speeds) previously mounted on the same bike. Despite 100 g more on the scale for the bare wheels, the Roval clinchers weigh in the end almost 30 g less, with an inner tube system.

A pressure sensor: a first

The 353 NSW incorporates a pressure monitoring system directly into the rim, a first of its kind in the bicycle industry.. Connected via Bluetooth to the SRAM AXS app and/or compatible computers (Garmin, Wahoo, Hammerhead), this sensor provides real-time pressure data. Powered by a CR2032 battery offering more than 400 days of battery life, it allows for accurate monitoring without the need for an external device.

The sensor works like the tire pressure monitoring system in modern cars, but here it is the user who determines his tolerance, via the application. Using the pressure guide provided by the brand, you can choose your ideal pressure, as well as the upper and lower limit of gain or loss of inflation which modifies the flashing of the LED light on the rim, from green (good pressure) to a slow red flash (pressure too low) or to a fast red flash (pressure too high). And always within the limits that you have chosen. For example, 0,4 bar (more or less) for me.

The concept is all the more interesting as it is associated with hookless rims, with a maximum authorized pressure of 5 bar, to avoid coming off the rim. I was able to realize that the pressure gauge on my floor pump was slightly pessimistic. Thus, by inflating to 4,9 bar according to my pump (just below the limit), I was able to control a real pressure of 5,2 bar. I thus chose on the SRAM AXS application an "ideal" pressure of 4,5 bar, with an alert threshold of 0,4 bar. I was also able to notice that over the days, the VectorR Z30 tires on the 353 NSW rims lost very little pressure, which is a very good point.

What do you think about the recommended low pressures?

According to Zipp, by entering my weight and that of my complete bike, I should normally inflate to 3,8 and 3,5 bar at the rear and front in the dry, and to 3,4 and 3,2 bar in the wet. This is a far cry from the 7 to 8 bar that was still used ten years ago with 23 mm tires.

Many riders praise these low pressures, especially for riding long distances on varied surfaces. Inflating less strongly provides more comfort with better vibration absorption, better grip, and less tread wear. as we have been able to observe in recent months by comparing, for example, 25 mm tires with 28 or 30 mm tires of the same tire models, necessarily used with less hard inflation.

Regarding the difference in pure yield, Zipp highlights its TSE concept (Total System Efficiency), which assesses the balance between wind resistance, weight, rolling resistance and vibration lossesThe rim width and low pressures reduce fatigue and indicate energy savings that could reach up to 50 watts depending on the brand on routes very grainy, to roll more smoothly.

Less than for a more sporty practice, on routeOverall good, I am not (yet) convinced of the advantagestagis low pressure, although obviously I have reduced it over the years by adopting larger tire sections. On the reference site bicyclerollingresistance.com, all testPerformance studies show that low pressure increases pure rolling resistance. Then, on accelerations, frequent changes of angle and passages in the dancer, too low pressure gives a vague sensation and makes the bike "float" a little laterally, making it less sharp in its reactions because of the sides which crush. I noticed, after a puncture of the front wheel (filled with liquid) and a reduction of the pressure to about 3 bar, that the steering of the bike was much more "sticky".

An ideal pressure?

I have testInflate wheels with Zipp's recommended inflation pressure, the maximum pressure allowed by the hookless system, and an intermediate pressure. I was thus able to observe clear differences in behavior:

• With the recommended inflation (around 3,5 bar), the comfort of the bike is very marked compared to usual, and especially in town on small cobblestones, concrete surfaces or when passing speed bumps. It feels like you are riding on a felted carpet, with an added feeling of security because the bike bounces much less, and therefore the grip is much better. On the other hand, when restarting and when standing, the wheels seem to lose their lateral rigidity. When transferring support, the bike is less responsive, less nervous. For me, it's a bit like when I ride with my shoes loose.
• With an intermediate inflation (4 bar), the wheels remain comfortable, but barely more responsive. On the flat, when riding fast with a gear ratio, you don't find the feeling of performance expected with these very high-end wheels.
• With a "limit" inflation (4,9 bar), I finally found the usual sensations of my bike, especially during demanding 15/15 sessions (alternating 15 seconds of sprinting with 15 seconds of recovery), without feeling too penalized in terms of comfort. On the other hand, on the famous portion of route concrete mentioned above, the bike tends to bounce much more.

Whether or not to adopt low inflation pressures should therefore depend on your practice, the terrain and your habits.. But it is absolutely not a miracle solution in my opinion.

Wheels that are always very smooth

The new Zipp 353 NSW adopts a slightly less pronounced profile than the previous model, and therefore offers a little less inertia on the flat, once a good cruising speed is reached. This is noticeable around 40 km/h, where it is necessary to work a little more than with higher rims to maintain speed.

Less than This lower profile also presents less wind resistance. It's a nice advancetage in many situations, increased here with the "wave" shape of the rims. The 353s are versatile, maneuverable, reassuring and very precise to drive.

What is striking, however, concerns the impression of fluidity that they give off, especially when freewheeling. Compared to other wheels, I was able to notice this when approaching roundabouts. When stopping pedaling as usual, I was sometimes forced to brake slightly to reduce my speed, where it is not normally necessary, proof that the 353 "roll" perfectly. The bearings of the hubs and the freewheel seem efficient, even after several hundred kilometers including a few outings in the rain.

In the bumps, finally, The 353s behave as you'd expect from fairly light wheels.. When climbing the train, they are efficient as the stopwatch can testify, without however appearing totally aerial. Firstly because the tubeless tires are not that light, secondly because the wheels are not extremely rigid, especially with the inflation pressure.

They are generally distinguished by their smoothness of operation rather than their incisive character. A temperament apparently intended by the brand when designing the wheels.

Up to the selling price?

The Zipp 353 NSW 2025, listed at €3, includes a lifetime warranty for standard use and are compatible with SRAM XDR, Shimano HG and Campagnolo (optional) cassette bodies.

Designed for cyclists looking for lightweight, versatile and cutting-edge wheels, They impress with their comfort, maneuverability and apparent robustness.

However, their innovative pressure sensor, useful in many circumstances, also equips the new Zipp 303 SW, 25mm internal width hookless wheels, slightly less aerodynamic, fitted with standard bearings and 100g heavier, but offered at €2 less.

So, The 353 NSW is aimed primarily at demanding enthusiasts, ready to invest in the latest technological advances to optimize their performance over long distances..

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