Following months of leaks and a year of patent-induced speculation, Zipp has officially unveiled its new 353 NSW and 303 SW wheelsets, complete with integrated live tyre pressure sensor technology.
Initially glimpsed at Omloop Het Nieuwsblad, on a set of 303s used by Tom Pidcock (Q36.5 Pro Cycling), the tyre pressure sensors immediately caused a flurry of excitement across the cycling tech world.
With the concurrent emergence of self-adjusting tyre systems at this year’s Spring Classics, it was easy for the cycling world’s collective imagination to run wild. However, a patent filed by SRAM in 2024 shed light on the internal working of the rim – essentially a natural evolution from Zipp’s TyreWiz system.
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Zipp has now revealed all details around the new wheelset, with the Zipp 353 and 303 becoming the very first AXS-connected wheelsets, bringing the wheels into SRAM’s suite of electronic systems with in-wheel tyre pressure monitoring integrated into the rim itself.
The AXS wheel sensor, on the surface, functions much as we’d expect: flashing a green light when the tyre is set to the correct pressure range and red when it falls outside of that. However, there has been impressive integration into SRAM’s wider ecosystem below the surface.
The system goes beyond binary red and green, and can be integrated with Hammerhead, Wahoo, and Garmin head units to provide real-time tyre pressure monitoring. In the case of the Hammerhead, that is displayed by two circles with live pressures and a green or red indicator to reflect whether it’s in the correct range. The system is also heavily integrated with SRAM’s AXS app, providing metrics and user guidance on the tyre pressure system.
Cyclingnews was in Indianapolis for the global launch event, where Zipp product manager Nathan Schickel explained the holistic theory behind the AXS sensor.
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“When you get your wheel with a Zipp AXS wheel sensor you’ll be able to add it to your AXS app, find your recommended tyre, learn how to install it – install the tyre based on an in-app animation, find your best tyre pressure, set it and then that will then help feed that information to your head unit,” he explained.
“Not only do you set your target pressure, but you set your variability range,” Shickel continued. “If your tyre pressure falls out of that chosen range, then not only will the blinking light when your wheel is stationary go from flashing green to flashing red, but the display on your Hammerhead screen will go from green to red.”
The unit itself is not entirely revolutionary but stands on the shoulders of the Quarq TyreWiz, owned by Zipp-parent company SRAM. Like the TyreWiz 2.0, this unit integrates the entire valve stem into the sensor system and uses a small gap in the stem itself to monitor live pressure readings.
The system is conceived as a fully tubeless setup, with Zipp shipping a custom tubeless sealant syringe that preserves the sensor from damage during setup.
A key step forward, though, is the introduction of a TPU tube that is fully compatible with the system. That means that if a puncture isn’t repairable with sealant or a plug, where previously a tube could be inserted but at the cost of live pressure readings, now that functionality is preserved. And of course, there are plenty of riders who simply prefer TPU tubes over tubeless and will default to this setup.
The unit is powered by a 2032 coin cell battery, which Zipp claimed offers 400 riding days’ worth of battery life.
Elsewhere, there are changes in both the 353, 303 and wider Zipp range.
Wheelset redesigns and ZR1 SL hubset
While the AXS tyre sensor is the main event, the 353 NSW and 303 SW have also had an upgrade across their wider design.
A revised carbon layup has seen wheelsets improve impact strength without weight increases, with Zipp claiming a 10% bump in strength for the 303, and a 16% jump in rim impact strength for the 353.
The 303 SW is technically a first iteration of the ‘SW’ moniker, but compared to the pre-existing 303 has undergone a refinement of its rim shape to help protect the tyre from pinch flats.
A central upgrade across the range has been Zipp’s ZR1 SL hubset for the NSW wheelsets. Modelled on the existing ZR1, the SL has trimmed down on weight, coming in at 304g with ceramic bearings, alongside 66 points of engagement.
Zipp’s 858 NSW has also undergone a minor upgrade, albeit largely focused on a 30g weight saving from switching in the ZR1 SL hubset. With tyre pressure optimisation surely a big lure for triathletes watching their watts and neurotic about a slow flat, we expect that the 858 may soon undergo a bigger update that integrates the AXS wheel sensor.
Zipp introduces aero tyres alongside a big leap in wider tyres trend
Zipp’s collaboration with Goodyear moved into full swing last year with the Goodyear Vector R Z30 SW tyres, designed to be paired with the 353 NSW wheelset. The wider Vector R Z35 SW was paired with the 303. The next step in the partnership is a substantial one, though, with the Goodyear Eagle F1 R Z29 Aero tyre entering the territory of custom aerodynamic integration with Zipp’s wheels.
The tyres use Aero Lip technology, which effectively blends the tyre-rim transition to create a smooth profile to the side of the wheel. Those with an obsessive memory of bike tech may remember the Mavic Cosmic CXR80 aero wheels, which employed a similar design concept, using an integrated plastic insert to cover the gap between the tyre edge and the rim wall. These are much subtler, simpler and more smartly integrated, but play to the same logic of changing the overall shape of the wheel.
“With new technology from Goodyear, we created an aero lip that blends the tyre into the rim and allows us to run a slightly wider section with for the same aerodynamics of a slightly narrower tyre,” explained Schickel.
Weighing in at a svelte 270g, they’re designed to measure 29mm on Zipp’s 23mm TSS (Tubeless Straight Side) – aka hookless – rim. That makes them most suited to pairing with Zipp’s 404 and 454 wheels, which underwent a similar update to the 858 with a hub switchout.
For us, the more interesting fruits of the Goodyear-Zipp partnership are the Goodyear Vector R XPLR.
If you’re a regular visitor to Cyclingnews, you will be familiar with our now-infamous tyre width test. Within it, we unearthed that 40mm tyres were faster for almost all road riding scenarios.
Zipp is a brand that is very much in the same school of thought, and the Goodyear Vector R XPLR is designed to measure 40mm on Zipp’s 32mm TSS rim, notably the rim used on the 303 XPLR.
“This is, personally, one of my favourite things,” Schickel said. “It is a road tyre built specifically for the 303 XPLR wheel. What we realised is that larger tyres on the road can pay off for a lot of riders.
“It has a 40mm section width. It’s designed around that Vector R casing. So it’s a durable casing, but it still rolls very fast. It has a very lightweight tread cap.”
For those interested in wide tyre gains on the road, the Goodyear Vector R XPLR will become one of the few 40mm tyres on the market, along with the Pirelli P-Zero Race 40mm and Cinturato Evo, with a design which is suited to road riding as well as gravel.
Zipp, encouragingly, doesn’t show any sign of slowing down on its wider-is-better trend. With even the road-focused 303 SW optimised around a 30-35mm tyre width, we could believe that the brand may soon seek to normalise road tyres closer to 40mm in width.
We’ll be testing the 353 NSW wheels and the new Goodyear Vector R XPLR tyres on Cyclingnews in the weeks to come. Stay tuned.
Prices
454 NSW Carbon Tubeless Disc Brake Rear (USD: $2,300, EUR: €2,100, GBP: £1,900, AUD: $3,955)
858 NSW Carbon Tubeless Disc Brake Front (USD: $1,900, EUR: €1,700, GBP: £1,500, AUD: $3,265)
858 NSW Carbon Tubeless Disc Brake Rear SR10/11SP (USD: $2,300, EUR: €2,100, GBP: £1,900, AUD: $3,955)
858 NSW Carbon Tubeless Disc Brake Rear XDR (USD: $2,300, EUR: €2,100, GBP: £1,900, AUD: $3,955)
Goodyear Eagle F1 R Z29 Aero Designed for Zipp Tubeless Tire 700x29c (USD: $90, EUR: €100, GBP: £90, AUD: $155)
Goodyear Vector R XPLR Designed for Zipp Tubeless Tire 700x40c (USD: $90, EUR: €100, GBP: £90, AUD: $155)
Zipp AXS Smart Tube TPU 28-35mm (USD: $40, EUR: €45, GBP: £40, AUD: $70)
Zipp AXS Smart Tube TPU 35-50mm (USD: $40, EUR: €45, GBP: £40, AUD: $70)
Zipp ZR1 SL Road Hub Front Disc 24H 12×100 (USD: $250, EUR: €280, GBP: £250, AUD: $380)
Zipp ZR1 SL Road Hub Rear Disc 24H 12×142 XDR Driver (USD: $450, EUR: €500, GBP: £450, AUD: $680)