SRAM’s high-performance wheel sub-brand, Zipp, has developed two new models specifically for gravel riding. The new 303 XPLR S and SW wheels feature a completely redesigned internal architecture and rim shape – and they are much wider than conventional gravel bike carbon rims.
As gravel bikers venture onto more demanding terrain, the product development trend is to borrow more inspiration from mountain biking instead of road riding.
With these new Zipp wheels, engineers wanted to reduce fatigue caused by rough terrain on demanding gravel bike routes while enhancing overall wheel and tyre aerodynamics. The solution is a much bigger gravel bike wheel with application-specific tyre options.
Going beyond 30mm
Mountain bikers have settled on 30mm being the ideal internal diameter for rim width, as the measurement creates a stable interface for running wide tyres at low pressures.
As evidence of how revolutionary its new wheels are, as opposed to being mild evolutions, Zipp has gone for an even wider rim width than most mountain bike wheels. Zipp’s 303 XPLR S and SW wheels feature a 32mm internal diameter. But why so wide?
Aside from the benefits of running larger tyres at lower pressures, the other product rationale is aero. Zipp’s product research discovered that deeper and wider rims were superior, creating the potential for a wheel and tyre profile that generates much less aerodynamic drag. That’s why the 303 XPLR carbon wheels have an internal width of 32mm and depth of 54mm, compared to many legacy gravel wheels that measure 25mm across and 40mm deep.
What do they weigh?
Zipp’s 303 XPLR S and SW carbon gravel wheels are similar in profile and depth, although the hub specifications and weights differ. The lighter 303 XPLR SW is claimed to weigh only 1496g, spinning German-made DB ZR1 hubs, while the 303 XPLR S is set to weigh 1642g, laced to DB 76/176 hubs. Pricing is $2100 for the 303 XPLR SW and $1400 for the 303 XPLR S.
Total system load ratings for the 303 XPLR wheels might be generous at 130kg (they’re fine for bike packing), but they’re not certified for technical trail mountain biking – despite the rim width. So no, these wheels aren’t an alternative for XC and XCO mountain bike racing.
The rim edge on Zipp’s 303 XPLR wheels has increased from 2.2- to 3.9mm, compared to the brand’s legacy gravel bike wheelsets. That additional surface area should reduce the risk of pinch flatting when navigating rocky or rooty terrain at speed with low tyre pressures.
Matching tyres from Goodyear
Evaluating the need for a complete wheel and tyre solution, Zipp’s 303 XPLR wheel team partnered with Goodyear, creating two new tyre models: the INTER and SLICK. These new Goodyear gravel tyres were specifically developed to work with the 303 XPLR rim width and aren’t recommended for fitment to any other gravel wheels.
For absolute speed in dry conditions, the 40mm wide SLICK weighs a claimed 455g and has a near slick centre tread, with a collection of shallow diagonally shaped sipes grouped in threes, facing each other. For enhanced cornering performance, the SLICK has raised circular tread lugs.
Zipp’s 303 XPLR riders who need more climbing, cornering and braking traction can opt for the Goodyear INTER, which is wider than a SLICK at 45mm and slightly heavier at around 525g. The INTER features a distinct centre tread pattern for enhanced braking in dusty or muddy conditions and a grouping of rectangular lugs spread from the centre to the casing’s shoulder.
Although designed for a tubeless set-up, these Goodyear SLICK and INTER tyres can run tubes when required, in an emergency, on the 303 XPLR wheels. Both these Goodyear tyre options are priced at $80.
Taking the drop with SL 70 XPLR handlebars
Beyond Zipp’s new ultra-wide gravel bike wheels, there’s also a handlebar designed to work more intuitively with SRAM’s Red XPLR AXS drivetrain.
Available in five widths (40-, 42-, 44-, 46-, and 48cm), the SL 70 XPLR handlebar range is shaped for more comfort and less fatigue on those demanding gravel rides. The SL 70 XPLR handlebars’ reference weight is 240g on a 42cm width.
With 70mm of reach and 115mm of drop, these handlebars have a geometry that shapes from five degrees of flare to an 11-degree out sweep, balancing the needs for rider comfort and control on those corrugated gravel bike riding surfaces.
Home mechanics will note that these SL 70 XPLR handlebars feature external routing, which can be guided into an internally routed stem. If you want easy access to your routing for emergency repair or maintenance on an endurance
Compatibility for safety features and endurance riding ergonomics? The SL 70 XPLR handlebars play nice with clip-ons, if you need to vary hand position on those multiday gravel adventure rides. Want to fit wireless blip controls? There is space for them under the tops and in the drops. Zipp’s SL 70 XPLR handlebar is priced at $340.
We will update with GBP prices as soon as we get them.