Zipp’s new 303 SW and 353 NSW wheels blend aero technology, redesigned rims and an electronic tyre pressure sensor, making them the brand's fastest all-round wheelsets to date.
The 303 SW and 353 NSW replace Zipp's renowned 303 Firecrest and 353 NSW wheelsets.
With revamped rims that have been made tougher and lighter, plus the new integrated wireless electronic tyre pressure sensor system, are Zipp’s new wheels the sign of tech to come or a step too far in data-driven riding?
That's something I aim to find out as soon as my test set of the new 303 SWs arrives.
Zipp 353 NSW – sawtooths and sensors
The new 353 NSW comes with an evolution of the undulating ‘sawtooth’ rim shape. It's the latest iteration of Zipp's waved inside edge, inspired by the tubercles of a Humpback Whale fin.
Zipp says the rim, which changes from 35mm to 40mm deep, is a shape that brings the aerodynamic benefits of a deeper rim. The effect is increased control in crosswinds, associated with a smaller rim sidewall.
The design follows the previous-generation wheels, with a varied dimple surface. Zipp claims these patterned dimples improve performance in crosswinds and straight-line speed.
So far, so similar. It is, however, what’s under the skin that brings the performance improvements, according to Zipp. The 353 NSW comes with a revised carbon layup and design. Zipp claims it has been able to improve the rim impact strength by 16%.
The rim is a hookless, flat-sided shape with a 25mm internal width. Zipp says this is optimised for 30mm road tyres. The 353 NSW has a claimed 1,310g complete weight (including rim tape, sensor unit/valves and lockrings).
The 353 NSWs also get a new ZR1 SL hubset, which is 30g lighter than its predecessor's hubs, with stainless steel bearings as standard (ceramic is an option).
The wheelset sports a 66-point engagement freehub, along with a new, lighter hub body.
Zipp hubs
For the first time, Zipp is making the ZR1 SL hubset available aftermarket with the ceramic bearing option. Zipp has stuck with J-bend spokes rather than shifting to straight-pull, a decision that should appeal to wheel builders.
The ZR1 hubs are approved for use with light-assist electric bikes for road or gravel, if the motor’s torque does not exceed 60Nm.
The hubs are available with SRAM XDR, Shimano HG11, Shimano Microspline and Campagnolo N3W freehubs, with 20-, 24- and 28-hole options.
Prices are £250 / $250 / €280 / AU$380 for the front hub and £450 / $450 / €500 / AU$680 for the rear hub.
Zipp 303 SW – tech-laden go-anywhere hoops
The 303 SW comes with a new rim profile that follows on from the massively wide 303 XPLR design.
The new rim remains 40mm deep with a broad 25mm internal width. Zipp says this is optimised for 30-35mm road tyres.
Utilising a wide rim design results in high aero efficiency and low rolling resistance on a wider tyre, according to Zipp. It's designed for modern road riding at lower tyre pressures.
The rim’s profile provides low drag and an improved transition between rim and tyre. Zipp also claims a wide-rim stance means less tyre deflection, helping to reduce rolling resistance.
Zipp tells us the benefits are increased volume and lower pressures to smooth out the ride. That means they absorb the shakes and bumps rather than transmitting them to the rider, resulting in less fatigue.
The 303 SW has also seen improvements to the carbon layup and rim design. Here, it results in a 10 per cent improvement in impact strength. The wheels also have a refined sidewall shape that Zipp claims helps to shield the tyre from impacts that would otherwise cause a pinch flat.
The 303 SW has an updated ZR1 hubset with an all-new stainless steel bearing set for improved durability. The claimed weight for the 303SW, including tubeless tape, sensors and valves, is 1,440g.
Sensors built in
Both the road-specific rim of the 353 NSW and the all-road-ready 303 SW are equipped with a Zipp AXS wheel sensor, a development from the original Quarq TyreWiz.
Rather than the sensor being attached to the valve, however, here it's housed in the rim itself via a pocket. As the name suggests, the Zipp AXS sensor integrates seamlessly into the AXS ecosystem.
However, because it has a Bluetooth transmitter, it can transmit to any Garmin, Wahoo or Hammerhead head unit. Hammerhead, like Zipp, also comes under the SRAM umbrella, which means the Hammerhead Karoo gets a native-specific screen. This shows independent tyre pressures, with graphic depictions alongside the key data.
Data analysis
This system enables you to both monitor and record tyre pressures over a ride. This means you’ll get fair warning if something isn’t right, a slow puncture, for instance. Or, if you hit a pothole hard, you’ll be able to tell instantly whether you’ve lost pressure.
It will also enable riders to experiment with and fine-tune pressures on their setup, with post-ride analysis comparing speeds and pressures, for instance. It will be great for cobbled courses and gravel routes.
The sensor unit also has an LED light built in, so you can tell the status of your tyres in an instant. If the LED is green, it’s at the pressure you set, and you're good to go. If it lights up red, you're too low. It also means you don’t need a pump with a gauge. The sensor light will simply turn green when it gets to your optimal pressure.
The sensor is powered by a CR2032 coin cell, the same as AXS shifters. The battery has a larger capacity than the original TyreWiz. Zipp claims more than 400 days of use thanks to a larger battery size and firmware upgrades to the original TyreWiz program.
The valve is specific to the sensor because it features a small cross-drilled port from which the sensor takes its readings.
Not tubeless-only
Although the wheels come set up for tubeless with these valves, if you aren’t a tubeless fan, both the 353 NSWs and 303 SWs can be run with tubes.
You will need Zipp’s TPU smart tube, which comes with the same cross-drilled valve. A single tube is included with the wheels, plus a sealant syringe with a needle adaptor that helps the sealant bypass the valve and go straight into the tyre.
Zipp says the valve won’t get blocked up and doesn’t need cleaning because of the Venturi effect created by the valve design.
The 353 NSW comes with a 114kg/250lb maximum system weight (rider and bicycle). The 303 SW has a 120kg/265lb maximum system weight.
Prices
The wheels are available with XDR or Shimano freehubs as standard, with a Campagnolo driver body sold separately.
The 353 NSW wheels are priced at:
- Front wheel, including sensor – £1,550 / $1,950 / €1,750 / AU$3,350
- Rear wheel including sensor – £1,950 / $2,350 / €2,150 / AU$4,040
The 303 SW wheels are priced at:
- Front wheel, including sensor – £800 / $1,050 / €900 / AU$ 1,600
- Rear wheel including sensor – £900 / $1,150 / €1,000 / AU$ 1,750
Zipp’s 454 NSW and 858 NSW get minor upgrades
Zipp’s aero-optimised deep-section wheelsets, the sawtooth-profile 454 NSW and 858 NSW, have both received upgrades to the new ZR1 SL hubset with ceramic bearings as standard.
The remaining specification and pricing remain the same, while the upgrade to the wheelsets sees a 30g reduction in overall weight across both models.
Lifetime warranty
Zipp’s lifetime warranty covers you against impact damage under normal use. So, the 353 NSWs, as purely road wheels, are fully covered – provided you don’t head for your local trail centre or skatepark and start launching them skywards.
The 303 SW is classified as a road/all-round/gravel wheelset, so in theory it's covered for more rugged riding.
