With every new product launch comes the typical laundry list of claims—Faster! Lighter! Stronger! You know the drill... Sure, there's always some truth there, but in reality the gains are usually quite marginal over the preceding product it's come to replace. A lot of hype leading up to a lack-luster reveal. So when we caught wind that Zipp was gearing up to unveil an update to the disc brake variant of their venerable 303, we kept our hopes high that this release wouldn't be just more of the same. The spec sheet made some pretty bold claims, and we we're eager to see if these new hoops would deliver.
Zipp unveiled these brand new 303 Firecrests just this past Thursday, but we were lucky to get our hands on a set a head of launch to check out up close and personal. Zipp has never been a brand to shy away from polarizing new products. They were one of the first to evolve away from traditional V shapes, moving toward the bulbous toroidal profiles, or the even obscurer jagged edge of the 454.
Given that, it did come as a bit of a surprise that at first glance these new wheels looked pretty familiar, with their bullet shape and iconic dimples, with really just the updated graphic treatment giving them away (which we do like, but are also glad to find they're just decals that can be removed if a stealthy, bare looks is desired.) After a closer investigation though, it became clear they were indeed different in nearly ever measurable way.
Taking the Featherweight Crown
The first thing we noticed upon picking them up was the weight. The previous disc brake 303s tipped the scale at 1,654g. Decent for a deep section wheel, but certainly nothing to write home about. The story is quite different for these new Firecrests. They not only lighter, but a lot lighter. Like 300g lighter. The new wheelset clocks in at an impressive 1,355g.
Let's stack that up to its competitors. Most would agree that the 303's most direct competitor is the Enve 3.4AR, a wheel that we love dearly, and exists in the same depth category as far as aero wheels go. When laced on Enve's in house hubs, the 3.4AR weigh about 60g heavier at 1,417g. And how about against something more exotic? Let's compare to the Lightweight Meilenstein Evo disc. The boutique German brand's most competitive wheel has surely got to be lighter, right? Nope. Zipp's got them beat there by about 25g.
A Subtly Refined Shape
While it might look similar, the shape has actually be completely redesigned. The new 303 Firecrest is 5mm shorter than the previous model at 40mm tall. It's also a bit wider. Internally, it's width has expanded from 21mm to a much more contemporary 25mm. Externally, the width grew a smidge from 29.9mm to an even 30. That counts right? The internal shape has also been improved. For one, it's now hookless, which helps save weight and also improves the performance of a tire's sidewall. That also means they're only compatible with tubeless ready tires. Sorry folks, no hand made cotton or silk open tubulars on these. The shape of the rim bed has also been engineered to make tubeless tire set up a breeze, even with a floor pump. We tested this with three different tire styles, and all of them inflated right up without a fuss. Hallelujah!
66 Points of Engagement
If we're being honest, Zipp's hubs have always been their weakest link. There was an era where Zipp hubs were plaged by cracking flanges and bearings that developed play prematurely. Luckily those days are long gone. While we'll credit them that their high end Cognition hubs found on NSW series wheels were quite a step up, their recent standard hubs have always seemed just that—standard, and not quite fitting of a premium wheel. It's what led us to ordering Zipp rims alone so we could build them to hubs of our choice.
We're really quite excited to see these new Firecrests feature a brand new ZR1 hub. While they don't have the fit and finish of say, a Chris King or Industry 9 hub, they seem notably more robust than Zipp hubs of the past. A new, German engineered freehub now has 66 pointed of engagement for instant acceleration. Oh and on a small not, they've finally made their own Center Lock brake rotor lock rings. Not that they're anything special, but it's always been a bit of a drag to put Shimano rings on an otherwise fully Sram/Zipp build.
Holistic Speed
Zipp has been synonymous with aerodynamics, but as we're seeing with more and more wheel engineers, aero is only a small part of the equation for speed. Rest assured, Zipp's 20+ years of aero experience are found in these new 303s, especially in how they perform across a broad range of yaw angles. Weight it certainly a factor, and as we addressed earlier, these new wheels have some huge improvements there.
Rolling resistance and vibration loss is the final major pillar to determining speed. And Zipp has approached this in a few different ways. For one, the new internal shape we discussed about greatly improves the performance of a high quality tubeless tire. We love tubulars, always will, but the science is pretty clear that a wider tire at lower relative pressure is indeed faster. Especially in the real world, where things like potholes, pave, and debris are a thing.
The tire interface is just the start. The entire structure of the rim has been tuned deliberately to have massive increases in vibration damping over the previous 303. More compliance means less bouncing, resulting in more speed, better traction, and less fatigue. As a bonus, the've also managed to make the rim stronger, and backed by a lifetime warranty. Surely that all sounds fantastic for road bikes, but you know what else? Gravel.
Let's get Dirty
While we've used 303s plenty on gravel bikes with good success, we've long wished for Zipp to come out with a true gravel rim. Enve's G23/27 wheels enlightened us to how good a purposefully engineered gravel wheel can ride on the rugged terrain. While this new 303 Firecrest isn't pegged exclusively for gravel, it's latest improvements in ride quality do indeed look promising for those who spend their time in dirt. I think we'll be seeing quite a few of these on future gravel and all-road builds. 
The Verdict
We really do have to tip our hats to Zipp on this one. The previous 303 was admittedly getting a bit long in the tooth as the competition around them really stacked up. With this new incarnation of the Firecrest, Zipp really rose to the occasion, and then some. We'll have to put more miles on them before we can truly say how significant the updates are, but on paper and in hand, these wheels are really something special, and we can't wait to spend more time on them.
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