Zipp's Wheel Overhaul Continues

Today Zipp launched more new road wheels with further evidence that this company is all-in on the course it began to chart last year. Thirteen months ago it was the 303 S and 303 Firecrest; then a couple of months ago the 353 NSW; and today’s it’s the 404 Firecrest and 454 NSW. In all these wheels what you see is: larger inner bead widths; and not just tubeless but hookless beads.

Technically, Zipp is announcing 3 new wheels today: the 404 Firecrest Carbon Tubeless as a road wheel, along with (for triathlon consideration) the 454 NSW (which has application for road and tri); and 858 NSW Carbon Tubeless. But I think the 858 only half-qualifies as a new product because its only change was a hub update. It’s the same rim that was launched just over a year ago, a (thinnish) 19mm inner bead width, and it's not hookless. More on the 858 NSW below.

I hope you can see the trends here, which we’ve been writing about for the past couple of years. It’s no secret the trend is toward wider inner bead widths, and hookless beads. More subtle but still important: The wheels are coming ready to ride, with tubeless tape laid down at the factory, valve factory-installed. What I’ve found on all these Zipp wheels is that tires bead up on them very easily. The tires snap onto the bead shelf and in some cases you have to use some sort of bead jack-like-thing to get the tires to reverse-suction off those bead shelves. I like this. The fitment is precise on these wheels, and I find the same thing with CADEX’s wheels. It almost seems like Zipp and CADEX are surveilling each other. On both CADEX and Zipp the tires bead up easily and barely leak down, even before sealant is put in there.

Bead widths

I think we can see where Zipp is going with its wheels. It’s 303 Firecrest (released last year) and the 353 (that terrific wheel released a couple of months ago, which I’ll talk about later) have hookless beads and inner bead widths of 25mm. That’s an expansive bead width for a road wheel. It’s not unprecedented. ENVE led the way on this with the 3.4 AR, which had a 25mm-wide hookless bead 5 years ago. But good ideas are good ideas, and that’s where the Zipp road wheels now are.

This 25mm bead width isn’t a good match for 25mm tires, and Zipp is saying that its wheels with this width are made for 28mm and 30mm tires. If you just look at the body language from ENVE, CADEX, Zipp, they all appear to be saying that for harsh road race applications (pavé or rideable dirt) 28mm is the narrowest road tire you should be riding, up to 32mm. While these are road wheels, gravel riders are often using these road wheels as well in 700c applications, with tires up to 40mm.

The wheels announced today – the 404 Firecrest and 454 NSW – are built around hookless beads, but are not quite so wide inside. They each are built with a 23mm inner bead diameter, and that’s because Zipp is not ready to jettison the 25mm tire width. Zipp’s idea is that the road tire you put on its new hookless road rims should be 2mm larger than the inner bead width, ideally, or up to 4mm wider. So, with a 23mm inner bead width, Zipp is telling us that these new 404 and 454 wheels are ideal for 25mm tires up to 28mm tires.

While I find that these 404 and 454 road wheels work great with tires up to 32mm, Zipp really has optimized its 303 and 353 for these larger (30mm and 32mm) road tire widths.


Let’s do the specs now and then I’ll close with a little speech on how these wheels were tested, because this is really interesting to me. But first, specs! These wheels just announced range from the moderately priced to the outrageously expensive, and these prices are for the pair:

Zipp 404 Firecrest: $1,900
Zipp 454 NSW: $4,000 (And this also comes as a tubular – aka sew up – wheel)
Zipp 858 NSW: $4,400

Before you go ape over the price of these obviously boutique road wheels, remember that the first new wheels of this type Zipp introduced were the 303 S and 303 Firecrest. The 303 S is the new generation wheel that started all of this, and is street-priced between $1,200 and $1,300 a pair. That wheelset weighs just a tick over 1,500g for the pair, and is a hookless-beaded wheel with 23mm of inner bead width. I would guess that with today’s launch, Zipp has completed its launch of new high-end carbon road race wheels, with prices ranging from $1,300 a pair to $4,000 a pair.

Here are the weights, per pair, of all these new wheels, those launched today along with those recently launched, along with which wheels get which new hubs (the ZR1 pawl-style hub is new; and the Cognition V2 is the new clutch-style hub):

Zipp 303 S: 1530g
Zipp 303 Firecrest: 1352g (ZR1 hub)
Zipp 353 NSW: 1255g (Cognition V2 hub)
Zipp 404 Firecrest: 1450 g(ZR1 hub)
Zipp 454 NSW: 1358g (Cognition V2 hub)
Zipp 858 NSW: 1773g (Cognition V2 hub)

The 454 NSW has really taken a weight haircut, and I think this is emblematic of what can be done with hookless beads. This wheelset now weights 1358g, and the previous 454 NSW weighed in at a portly 1700g and change.

All these wheels use Centerlock fixing systems for disc rotors, and I believe this probably completes Zipp’s migration from 6-bolt to Centerlock, and lock rings are included with all these wheels.

Let's talk about pressures for a moment. These wider inner beads, and the invitation to consider larger tires, mean the volume of compressed air in these wheel systems has gone way up. The more air volume, the lower the pressure. Here is what Zipp recommends for air pressures for the 404 Firecrest and 454 NSW:

I find that this tracks pretty well with my own experience. As an exercise I’ve been filling up my tires on these wheels, going out riding, up and down, smooth roads and bad roads, getting off the bike and letting a little pressure out of the tires until I get what I consider the right balance of speed, comfort, handling. What I’m finding is that the upper pressure limit for these 23mm to 25mm inner bead widths is: 55psi for 30mm tires; 65psi for 28mm tires; 75psi for 25mm tires.

Zipp’s warranty on its wheels is lifetime for product defects, and it’s got a crash replacement policy as well, also lifetime, but I don’t know details of this. This is on 2021 wheels offered after May 5th of 2020.

There’s an all-new narrative for testing

Below is rejiggered (by me) slide off a Zipp deck that shows how Zipp classifies the media through which its wheels must pass (through the air, over the ground), and the friction associated with each. Zipp calls these “barriers to speed.” Note vibration as one of the four barriers. Both CADEX and Zipp talk a lot about vibration as a penalty, and this is rather new.

I don’t know how Zipp has come upon the degrees of arc each “barrier to speed” is given per each cycling specialty. Maybe it’s part science and part “for the purpose of illustration.” The point is, vibration has rarely been part of that drag calculus. You can imagine how vibration could impact speed if you ride a gravel bike down a washboard road.

But here is where it gets interesting, to me: How is this measured? What I do know about Zipp, and the development of a lot of these new wheels (in particular the Sawtooth-design wheels), is that aero sensor testing played a big part in this. This is also new. Before, it was all about the wind tunnel. Now it’s field trails with an aero sensor, and I think "system vibration" is probably the aero sensor’s “diagnosis by elimination.”

Here is the interesting thing: These new wheels don’t test any faster than the old versions of the wheels, if we just consider aerodynamics (which was the only thing we used to consider). But in the chart above, this is what Zipp has come up with. This is the result of the field testing they’ve done. I don’t think this is an end result; I think it’s a beginning of a discussion. I’m not sure I can stipulate that vibration is the spooky action in the universe that accounts for the efficiency gains. I’m not disputing it. I just think we’re onto a new way of looking at wheel performance and, if so, we’re also onto a new way of looking at frame and tire performance.

Vibration cropping up in the narrative is not simply a Zipp thing. Again, CADEX is keeping pace with Zipp on this, and it’s not one brand drafting the other, it’s that each are focusing on wide inner beads, hookless beads, and vibration as a previously omitted drag culprit.

The 858 NSW

The 858 NSW tubeless is the outlier in all of this. This wheel is still built with a 19mm inner bead width, and a hooked bead. According to my memory it was ridden by Kienle, Frodeno and Ali Brownlee in the 2019 Hawaiian IRONMAN, which means it was ridden tubeless. But it hadn’t (in that 2019 race) been released for sale as a tubeless wheel. Were these guys riding a non-tubeless wheel tubeless? (It wouldn’t have been the first time something like that had happened.)

The mystery was solved in April of last year when the tubeless version of this wheel got officially launched and offered for sale. So, what is today's introduction all about? In fact, the only change in this wheel announced today is the hub. Now, to be sure, the Zipp Cognition hubs are cool, and we’re getting ready to write about these new-style clutch-type hubs that are, little by little, replacing the traditional pawl-and-ratchet-ring hubs. But that’s the only update to the 858 NSW.

This will remain an “older” style wheel until one of two things happens: Continental and/or Vittoria release a tire optimized for hookless beads; or Zipp just gets around to bringing this wheel up to the same tech it’s releasing today with the 454 NSW. I will eat my hat if Continental doesn’t launch a new performance tire for hookless beads this year. I will eat a shoe if Vittoria doesn’t have one out by a year from today. But here is what this means: If I can ride with 4 or 8 or 12 fewer watts just by incorporating 23mm hookless beads, why would I pay north of $4,000 for a wheelset a year before that wheel comes out? To be clear, I have no information that a new hookless 23mm-bead is the next iteration of the 858 NSW. But why would that not be the case?

The 353 NSW

This wheel got launched a couple of months ago, so I’ve had the privilege of riding this wheel against the new Zipp 404 Firecrest, and some other cool wheelsets rolling across my transom (like the CADEX 36). The 353 NSW is a complete show-stopper as a road wheel. While the 404 Firecrest may be marginally more aero (I don’t know), a few weeks ago I had a string of days where it was windy as heck, and all I felt like doing was riding up and down a tallish, steep twisty mountain outside my home. I was very impressed with everything about the 353, especially how just crackerjack it was in how it handled the descents.

Why is this wheel so good? The Sawtooth profile of these NSW wheels are what Zipp calls Hyperfoils and generate what it calls AirBalance. Whatever you say, Zipp. I have not ridden the 454 NSW, and I guess the real test of AirBalance is whether I can ride this taller rim profile down a twisty descent in 25mph winds. But I’m gaga over the 353 NSW.

Available tires

This is the bugaboo, for the hookless models above. I’m having great luck with Schwalbe’s road tires on these wheels. But the world is bigger than just Schwalbe. Remember what’s going on here: The ETRTO – the European quasi-governmental body in charge of all pneumatic tire specs, from wheelbarrows to jet aircraft – generated specs for hookless beaded bicycle wheels. This was in 2019. Tire companies must now manufacture to this spec, and many tire brands are running pre-2019 molds. Zipp’s own tires, and tires from Pirelli, Goodyear, Rene Herse, Panaracer, and one Specialized tire (the SW Turbo RapidAir) are hookless-compliant. We’re awaiting others, most notably Vittoria and Continental. As noted above, I’m almost ready to start holding my breath. I suspect we’re close. I just this minute got an answer from Veloflex on this topic, as this company has recently elbowed its way into the tubeless conversation with some very fast tires. These tubeless tires are hookless compliant, and you can read about that on Veloflex's site.

Here is more info on the Zipp 404 Firecrest, and the other wheels written about above.