Zipp 303 Firecrest Carbon Clincher Wheelset

• MSRP: Front wheel-$1,215. Rear wheel-$1,485. $2,700 for the set.
• Weight
  - Claimed weight, wheelset without quick releases: 1498 grams. Actual weight: 1535 grams; this included rim strips which likely makes up the 37 gram difference.
  - Front wheel: 680 grams (claimed). 690 grams actual with rim strip.
  - Rear wheel:  818 grams (claimed). 845 grams actual with rim strip.
  - Quick Releases: Front, 37 grams. Rear, 41 grams.
  - Zipp Tangente tires: 260 grams each.
  - Zipp tubes with valve extender: 11 grams each.
• Wide 27 mm rim width for stability, lower rolling and wind resistance
• Tall 45 mm rim height for aerodynamics.
• 125 psi max

What's all the fuss?
Road bikers and triathletes looking to improve performance typically choose two paths; lighter weight or better aerodynamics. Until recently, getting both in a reliable clincher configuration has been challenging. Light weight clincher wheels typically have a short profile which reduces weight, but this low profile isn't as aerodynamic. Aerodynamic rims are typically taller and thus require more mass to build so they are heavier.  Tubular wheels are significantly lighter--and can be both aero and light weight--but tubulars are extremely troublesome to install and fixing a flat on the road can be problematic. To achieve light weight AND aerodynamics in a clincher, wheel manufacturers have been focusing on carbon construction because of its inherent light weight, moldability, and strength. 

So is the perfect answer a carbon clincher? Unfortunately, it's still not clear. Relative to aluminum, carbon is a poor braking surface because it is much "slicker". This means that brake pads work harder to slow the bike, which creates additional heat on the rim. As the wheel heats up, expanding the volume in the inner tube, tires have been known to slip off the rim causing the tube to burst. Sometimes the friction created actually results in melting the carbon and epoxy of the rim, rendering the rim unusable if not downright dangerous. Both cases are pretty worrisome for cyclists. The last thing you want to do is worry about your tires exploding off on a hairy descent!

Given all of these challenges, how would the Zipp 303 Firecrest Carbon Clincher wheelset fair?  On the surface, they seem to have all the attributes.

• Light weight - check. These wheels are exceptionally light at around 1500 grams for the set.
• Reliable braking - check. They feature a reinforced braking surface to help prevent de-lamination on big descents.
• Aerodynamics - check. They have a tallish rim profile of 45mm for aerodynamics, coupled with an extremely wide 27 mm rim for enhanced stability and a claimed lower rolling resistance.
• Additionally, the unique rim shape is said to reduce the affects of cross-winds dramatically. Even the tires are purpose built to smooth airflow seamlessly across the front of the tire, transitioning to the bead, and off the rim.

So how did they ride?
It wasn't love at first sight with these wheels. The massively wide rim was a challenge; my road bike has Zero Gravity brakes and I had to file down an already heavily worn pair of brake pads to fit the wheels in. Fortunately, my triathlon bike, the Fuji D-6, was already set up to accept wide HED Jet wheels and, after some tinkering, finally got them to work as well.

In any case, once on the road, I was immediately impressed. They are very stiff vertically and accelerate quickly. They also felt "bullet proof"--not wispy like a superlight climbing wheel. On the flats, the aero benefits were definitely noticeable; they felt nearly as fast as the current 60mm front/90mm rear combo that I normally ride on with Fuji D-6 triathlon bike. On a glorious stretch of several miles I towed a fellow road biker (who happened to be running Zipp 404 Firecrests) at speeds well over 30 mph. The wheels were awesome!

Were they affected by crosswinds? At 150 pounds, cross winds do affect me. And with these wheels, they still did. However, unlike traditional aero wheels, the 303's were extremely easy to steer right back in line. There wasn't the heavy and alarming resistance that is typical of other aero rim designs. Zipp explains it as such:

"By moving the center of pressure – the focal point of side forces on the rim – to its optimal location near the steering axis, Firecrest offers stable, predictable handling at every wind angle."

The fellow rider on the 404's explained it as a "caster effect". Imaging you are pushing a shopping cart and the wheel is reversed with the mass way out in front. When you push, the wheel swings back in to line, tugging the whole cart with it. Now think of the wheel in it's proper orientation; it steers and self-corrects easily. This helped me visualize how these Zipps work. And you really feel it in practice; the wind may tug at the wheels but they come back to straight with very little drama or effort. With older deep wheel designs, in strong winds, it feels more like the wind is coming at you, trying to push the bike out from under you. The 303 Firecrest design really is dremarkably different and more stable.

Additionally, the wheels braked exceptionally well; I didn't notice a performance difference relative to aluminum rims and the pads didn't squeal.

Quibbles? The preload on the rear bearing seemed to be a little loose and there was some horizontal play in the wheel; going over road debris was a bit jarring at times. I didn't fiddle with the preload but it's something I'd have a mechanic dial in.

Wrap Up
The Zipp 303 Firecrest clinchers live up to the hype. They are truly all purpose wheels that are light and rigid enough for climbing while also being exceptionally aero. They felt bullet proof and solid, accelerated quickly and held speed well. Zipp also really adds some nice touches--the hubs are beautiful and seem almost jewel-like. Even the skewers are elegantly designed and feature a serial # for each wheel. Even the rim strip was elegantly executed, clearly labeling the maximum tire inflation pressure.

At $2,700, these wheels are not cheap, however, at any triathlon, you'll see that Zipps are extremely popular; their customers are already spending big for a race day wheelset. As an all-rounder, the 303 Firecrests are extremely versatile. They would be fantastic in triathlon use (perhaps put a disc cover on the rear wheel), would be phenomenal in bike racing, are strong enough for 'cross, and would make you feel like a hero in training rides. Given the versatility, perhaps the price isn't that outrageous after all.

Value: 4.5 stars (if  you can afford 'em!)
Overall: 5.0 stars