Zipp 404 Firecrest Carbon Tubeless Disc Brake wheelset

The new Zipp 404 Firecrest Carbon Tubeless Disc Brake wheels have been on a serious diet. Not only have they dropped to a competitive weight for a 58mm deep wheelset, they've also dropped £800 over the previous iteration. The performance is excellent, they're quick and stiff, but the hookless rims do (for now) limit tyre choice.

The 404 Firecrest is a classic in the Zipp lineup, marketed as an 'all-round speed weapon' with its 58mm deep rims being suitable for anything from hilly road races to triathlon or time-trials. Thanks to the hookless rims – more on that later – the price has dropped substantially to a far more competitive level.

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The 404s stick with a conventional rim shape rather than the sawtooth design seen on the more expensive 454 NSW, but keep the dimpled rim surfaces of old to improve aero efficiency.

With a claimed weight of 1,450g, Zipp has made leaps forward – on our scales they did weigh slightly more (1,530g), but that was with tubeless tape and valves installed. Compared to other wheels of this depth it's very competitive; for example, the Reynolds AR58/62 X DB wheelset weighs much more at 1,711g, while the Zipps aren't much heavier than the very light (1410g) Roval Rapide CLXs, despite those having a shallower front rim and forgoing tubeless compatibility to reach this weight.

Off the hook

Going hookless certainly has its advantages then – the lower manufacturing costs have actually made their way to the consumer, and there's a substantial weight reduction. Despite this, there is undoubtedly still some trepidation about the move to straight-sided rim walls, and it is still a relatively new idea for road wheelsets.

I have to admit that, before reviewing this wheelset I was skeptical about using the hookless on the road, where pressures are much higher. To overcome this, like on the 303 S wheelset that we reviewed last year, the wheels have a relatively low maximum pressure recommendation of just 72psi.

That does limit usable tyre widths somewhat and, in general, you'll find a 28mm tyre is necessary (a 26mm can be used from a few brands). That doesn't bother me personally as, having trained on 28s for the last few years, I now choose to race on them as well.

One issue is that some tyre manufacturers prohibit use with hookless rims, limiting you to certain brands. Zipp's hookless compatibility list is actually relatively comprehensive compared to some, but I still found myself unable to use my favourite Vittoria tyres, or my 26mm Pirelli P Zero Race TLR SLs, to name just two. So, hookless has its benefits, but don't expect to use anything narrow or clincher – although you can chuck a tube in instead of sealant if you so wish.

Fitting

Fitting tyres to the rims was extremely easy. I tried multiple sets, including Goodyear Eagle F1s and Schwalbe Pro Ones, and didn't even require an air shot. I was also pleasantly surprised by the reassuring pop as the tyres seated. Having used the 404s for six weeks I am now much more confident in the hookless design and, assuming the correct tyres are used, they're not likely to blow off the rim as some might fear.

There is still the issue of tyres coming off the rims during a rapid deflation, but as this has happened to me on clinchers, I'm not convinced the risk is substantially higher.

Another positive of hookless is the tyre/rim interface. Rims have been getting wider and wider to improve the transition between the tyre and wheel, but I've never seen any quite as smooth as the Zipps with 28mm tyres on. The 23mm internal-width rim transitions almost seamlessly – although we are unable to test it, I can see that being advantageous to aerodynamics.

The outer rim shape is also new; the 58mm profile is slightly more V-shaped than the modern U-shaped rims we have become accustomed to, but despite this I was pleasantly surprised with how the wheels handled in crosswinds and going past gateways.

Double dimples

While you might think smooth surfaces would work best, Zipp says the dimpled rims are now more dimpled than ever before. These dimples create a thin boundary layer that sticks to the surface of the rim as it moves through the air, which might sound like a bad thing, but it actually eases the airflow's separation into the wake, and therefore reduces drag.

Laced to these rims are 24 J-bend spokes (front and rear), with external spoke nipples for ease of truing. The wheels climb extremely well, partially thanks to the new lower weight, but more so because of the stiffness. During hard accelerations and sprints there is no noticeable flex laterally, and they also sound great when riding out the saddle – the way only a deep carbon wheel can.

At the rear, Zipp's new ZR1 DB hub is near enough instantaneous even at low speeds, which adds to the 404s' overall feeling of responsiveness. Its six pawls and 66 points of engagement give an engagement angle of just 5.45 degrees – a welcome step up from the 32-tooth ratchet system of the 303S wheelset, which Matt found awkward on bumpy roads.

As with most modern wheels, the 404s are available with a Shimano/SRAM or XDR 11-speed freehub body, while a Campagnolo freehub is available separately. All three are steel which, although heavier than aluminium, is better for durability.

Axles

Both wheels come with 12mm thru axle end caps, although you may want to grease the inside of these before use to prevent a loud clicking when climbing – that sound took me a few rides to track down. Along with the seals and dust caps, the ZR1 hubs borrow the bearing sizes from the premium Cognition freehub used on the NSW wheelset, although here the bearings are steel rather than ceramic.

In real life, that's going to make the most marginal of differences, but is one of the reasons the 404s are so much cheaper than the 454s. Of course, if this is something that bothers you they can be upgraded: Ceramicspeed, for example, make the 6903/61903 bearings that both the front and rear require.

It's not uncommon for me to receive a wheelset with bearings not turning as quite as freely as I would like, and they sometimes require a few rides to 'bed in'. However, with the 404s this resistance turned in to a loud squeaking at speed, and I opened them up to find the front wheel bearings completely dry.

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This could well just be a one off and something I'm sure Zipp would be only too happy to rectify, but it isn't the quality control you expect from even a £300 wheelset – let alone a £1,600 one. Still, a dosing of lubricant got the wheels spinning as they should, and the squeaking stopped.

Value

At £1,600 the new 404s are hardly cheap, but having dropped a massive £800 over the previous generation it's now £250 cheaper than the Roval Rapide CLX (£1,850) wheelset which, although it's lighter, isn't tubeless ready. The 404s are also lighter than the similarly deep, 1,680g Swiss Side Hadron2 Ultimate 625s. They also handle excellently in the wind, though cost more at £1,920.

There are still cheaper options out there (other than building your own), such as the Hunt 60 Limitless Aero Disc wheelset – it's a relative bargain at £1,189 but is once again heavier at 1,669g.

Overall

The 404s are seriously impressive. They've gone a long way to convince me of the benefits of hookless design, and the weight savings and price drop are undeniable. While limited now, tyre choice should continue to improve as more and more tyre manufacturers get on board, too.

But the quality control of this particular wheelset is disappointing, although easily remedied. Zipp claims the new 404s save 4 watts at 40kph over the previous generation, and although we are unable to test this, the 404s do feel fast no matter the terrain.

They're stiff and light enough for me to knock out some PR climbing performances, aero enough for a TT, and handle surprisingly well considering their 58mm depth.

Verdict

Lighter, faster and cheaper, the new 404s are excellent allrounders – so long as you're prepared to go hookless