Zipp’s 303 carbon rim wheels have been a mainstay in US cyclocross races and European spring classics since they were redesigned in 2010 to be wider than the average road rim. Although the company tweaked the 45mm deep rim’s profile again two years ago to go from the toroidal shape to the new Firecrest shape for better aerodynamics, and dropped their cyclocross-specific model (noting that the lower spoke count of the “standard” version of their wheels is plenty strong enough), the tubular version of the high-end wheel remains one of the top cyclocross wheelsets available due to its wider gluing surface, vertical compliance, light weight and good (for carbon) braking surface.
Add disc brakes into the equation, and the braking surface component goes away, but the Cannondale p/b CyclocrossWorld team still raced the Zipp 303 rims last year, riding custom wheelsets not available to the public. Paired with SRAM’s Rise 60 mountain bike hubs, the team raced these wheels to numerous podium appearances. With disc brakes growing in popularity and racers like Tim Johnson and Ryan Trebon proving that the rims can hold up to the different stresses presented by disc brakes, Zipp decided it was time to offer the public a disc version of their 303 Firecrest tubular and clincher wheels. The disc option adds a bit of weight and adds a bit to the price tag. The tubular 303 disc brake wheelset retails for $2,500, $100 more than the non-disc brake version.
For the production model of the 303 disc brake wheels, Zipp decided to design disc brake versions of their own 88 and 188 hubs, instead of using the SRAM Rise 60 hubs. With the addition of disc brake rotor mounts, the Zipp hubs’ names no longer reflect their weight, but still feature Swiss stainless steel bearings. The rear hub disc hub features a red anodized alloy freehub body, just like the non-disc version, but expands to 135mm rear spacing, and both disc brake and non-disc brake hubs are now compatible with 11-speed cassettes. Campagnolo and Shimano/SRAM freehubs are available.
To combat the new braking forces for disc brakes, Zipp added six more spokes to the front wheel, going from 18 spokes on the non-disc brake tubular 303 to 24. To resist the twisting forces of the disc brake hub and rotor, Zipp swapped out its front wheel radial lacing to a two cross lacing pattern, which means spokes are longer (and thus a bit heavier). With the added weight from the disc brake hub, more spokes and longer spokes, the front wheel adds 95g. It’s worth noting that when disc brakes and weight are discussed, many tout the potential weight savings due to lighter rims that don’t have to withstand rim braking’s forces and wear, but more/longer spokes needed to withstand disc brake forces can offset any such weight savings.
The rear wheel (which already was designed to withstand the wind-up forces from the drive side) maintains a 24 spoke count, but moves from a radial (non-drive side) and two cross lacing on the drive side to what Zipp calls “virtual three cross” lacing on both sides. “Virtual” means the one spoke doesn’t actually touch both spokes it crosses, due to flange thickness and diameter, even though the line of the spoke crosses that of two others. The rear wheel, with the disc brake hub and the longer spokes, weighs 85g more than the non disc brake version, at 775g.
Why not shed some weight with a disc brake-specific rim? Zipp’s Andy Paskins has said the company kept the rim the same, not because of resource constraints, but because the same amount of material was needed to retain the rim’s aerodynamics and stiffness. But don’t have any illusions of buying these wheels for dual duty use and removing the rotor to put the front wheel on a rim brake road (or cyclocross) bike in the off-season, because Paskins told Cyclocross Magazine that they do not sand the brake track like they do on the rim brake models. “You definitely don’t want to try that,” Paskins emphasized, alluding to unsafe braking with the unsanded brake track.
The company also offers clincher versions of these wheels, and the clincher rim adds around 120g to each wheel and another $300 to the wheelset price ($2800).
I had an opportunity to take a clincher version of the 303 Firecrest disc brake wheelset into the hills around Monterey during Sea Otter 2013, riding road clinchers paired with road slicks and SRAM Red hydraulic disc brakes. While our ride wasn’t exactly mimicking cyclocross conditions, it confirmed that the wheels remain quick accelerating and are quite stiff under power, and even with the high pressure road tires, didn’t feel harsh — all factors in us awarding the Zipp 303 Firecrest wheels our Editor’s Award for best high-end wheelset. It was also nice to look down, see a carbon rim, but not think a second about how I may need to change my riding style because of poor carbon braking.
I didn’t have to change wheels on my one test ride, but one thing about the disc version of the Zipp 303 Firecrest wheels that will be comforting to anyone who has had to dramatically readjust his cantilever brakes the night before a race to accommodate the wider 303 rims is that those days are over. Swapping to wider race day or training rims should be a simple affair with disc brakes.
Stay tuned as we put a set to the test with true cyclocross tires and riding.
Zipp 303 Firecrest Disc Brake Carbon Tubular Wheelset Specs:
MSRP: $1130 front wheel, $1370 rear wheel, $2500 pair (clincher is $1272/$1553, $2800 for the pair)
Rim: Carbon tubular rim, 24.5mm external bead width, 28.5mm max width, 45mm deep, 352g
Hubs: Zipp 88 disc front, Zipp 188 disc rear, 24 hole, alloy freehub, 11-speed compatible
Spokes: Stainless steel bladed, 24 two cross front, 24 “virtual” three cross rear
Weight: 660g front (780g clincher), 775g rear (900g clincher), 1435g pair (1680g clincher)
More info: Zipp.com
Zipp 303 Firecrest Disc Brake Carbon Wheelset Photo Gallery: