Zipp 303 Firecrest Carbon Clincher Wheelset
The one wheelset life. To us, it seems like folly; three seems about right. Have a solid 28- or 32-spoke set of aluminum-rimmed clinchers for year 'round daily use. This is the set that gets pummeled; dress them in heavy tires with heavy tubes. Then have a set of carbon race clinchers for local and flatter racing. Race tires and latex tubes. Than have a set of carbon race tubulars for out of town and hillier racing. Racing tubulars. The three sets cover all the possibilities, save time trialing, and you can probably get a decent wheel cover for one of the rear wheels and use that as your faux disc.
We've been on the three-set life for over a decade, and our daily front wheel is built around a hub that has been in service for 20 years. It's a powerful reminder of what good components can do. We've actually worn out a few aluminum rims at the brake track.
But simplifying also has its benefits. Less gear to keep up with is less time spent on maintenance. It affords more room. It's cheaper, somewhat, as you'd probably ride race tires in the summer.
This is where the Zipp 303 Firecrest Clincher rolls in. It's a fancy high-tech race wheel, but as a clincher, it can also do daily duty. Carbon clincher technology was around for several years before Zipp tried to master the form. Their lateness had benefits; they could see what others had done, what worked, and what didin't. Simultaneously, they had been working on improving the strength of their tubular rims to the point that their sponsored teams run carbon rims over everything roads and cyclocross courses can dish out. Presumably, thanks to work on both fronts, they can offer a stronger wheel with better braking.
We've cracked three Zipp rims in races over the years, two on wheel-eating potholes, one after being run over or landing on a rock in a crash, so we know that Zipp isn't perfect—though none were this latest iteration. It's hard to say if any aluminum rim would have survived the same stress—and we've tweaked four aluminum rims in the same time, two in races, two just riding around.
We tested the Zipp 404 Firecrest Carbon Clincher when it debuted. It is an impressive wheelset. No wheel is perfect, but looking at all it had going and the riding we do, the compromises it represented seemed minimal. The wheel weight was lighter than our everyday set, and lighter than the Zipp Aluminum/Carbon 303 clincher as well. The 404's 58mm depth looks excessive on a slow ride—not that anyone is buying the wheelset to tool around at 12mph on bike paths. We barely noticed any crosswind issues, but that could be a result of having gotten comfortable riding 80mm deep wheels. Braking was pretty good, and the wheel was awesome at race speed.
Still, there was the whole aero vs. light issue. And if we were going to continue with multiple wheelsets, should the local race wheel, the clincher, tilt toward aero or light? We were thinking aero until we noticed something in Zipp's marketing materials. They claim the 303 Firecrest shape is 8% faster than the previous 303 tubular. Zipp reports a savings of 72 seconds compared to a conventional wheelset over 40k, or 24 watts on the older 303. The 404 Firecrest is reported to save 80 seconds or, 27 watts. So, assuming their calculations are correct, the new 303 Firecrest wheels put you at a savings of 77.76 seconds in a 40k, or 25.92 watts. So it seems to have just about closed the gap between the two wheels at near race speeds. Impossible, based on this data, to say whether one wheel or the other is better at higher speeds, but the 303 appears to be better at lower speeds and should have even less of a crosswind issue.
It was time to test them out. Zipp claims a front wheel weight of 680g and rear wheel at 818g, or 1498g for the set. We weighed them at 660g front and 800g rear, for a total of 1460g. Getting better and better.
We installed the rim strips, easily pushed on the heavy-duty training tires by hand, pumped up, installed Zipp's Tangente Platinum Pro brake pads and went. The platinum pads are made by SwissStop and are the current most highly recommended pad by Zipp. That is, the pad that should offer the best overall performance, which to us means good durability, modulation, and wet-weather braking.
On our second ride, we came into a tight 180-degree turn on a ramp. We were going slowly, like 5mph, and someone was coming up faster than we expected and we jammed on the brakes. The bike came to a standstill faster than we expected and we just about toppled over. After that experience, it seemed our ability to modulate got better.
That was the first of only two questionable experiences on the Platinum pads. The second was in a blinding rainstorm and the pads didn't seem to grab fast enough. But then, probably nothing, not even disc rotors, would have stopped quickly.
The only limitation with the Platinum pads is that they're not recommended for use with aluminum rims. This limitation is only relevant for people who feel they might need to switch to aluminum rims in a race, like when you flat and are looking for a spare, any spare. It's for this reason we switched to SwissStop Carbon King pads. Braking was a little more grabby at the moment the pads touch the rims, but excellent after that.
Early into our time on the wheels, we did a Gran Fondo, after swapping in race tires and tubes. Over 8000' of climbing in 110 miles. The wheels were great; looking at our speeds on the climbs, probably only one of them, and it was only a mile, was adversely impacted by the weight of the wheels, the rest probably benefited from the aerodynamics. We've also raced them in road races and criteriums, on smooth roads and rough. We've gone over 50mph on them and ground out single digits on double-digit ascents. While the weight, compared to a tubular, was a drawback on the steepest climbs, everywhere else, the wheel seems to be at no disadvantage.
One of the things we tried to really pay attention to was the difference between the wider rims and narrower rims. After two months on the Zipps, which has a 17.25mm inside width from bead to bead and a 25.14mm width on the outside of the rim, we switched back to our narrow, box-section, aluminum clinchers. The narrow-rimmed front wheel seems to move around more. It feels less stable. It reminded us of the time we had on double-wide mountain bike rims, which helped the tires feel stable riding over sheet ice. In terms of cornering, the wider feel a bit more stable, but only a bit; a less-pronounced transition.
We can believe the extra air volume does protect the rim as we've treated these wheels like any aluminum wheelset and have had no problems. No pinch flats, no bottoming out sensations. We'd like to believe it has reduced rolling resistance and improved traction, too, but those are nearly impossible to quantify outside of a lab.
One surprising thing we've noticed is that tires seem to be lasting longer. Could just be luck, but the rear tire appeared to take longer to develop that inevitable flattened section in the middle, and, thanks to the width, the transition from the flattened part has a less-pronounced transition to the curved portion of the tread. We asked Zipp about this and they believe that while the contact patch has changed, the wear shouldn't be much different.
Since wheel swapping back from our aluminum clinchers to the Zipp 303s entails not only swapping brake pads, but adjusting brakes, we find ourselves getting lazy and leaving the wheels on, post-race. Might as well feel a little bit faster on that recovery ride the next day. And the day after that, intervals, it's nice to have the faster wheels there, too. It's the first time in ages we've contemplated one wheelset for everything.