ENGINEERS EXPLAIN THE NEW 858 NSW AND 808 FIRECREST

Zipp’s deep-section wheels, the 858 NSW and 808 Firecrest, epitomize our drive to make you faster. These two wheelsets are our go-to weapons for triathletes and time trial specialists.

Now, Zipp’s 858 NSW and 808 Firecrest pack even more speed thanks to the addition of our Total System Efficiency design with the hookless rim-tire interface. What’s more, each of these wheelsets is hundreds of grams lighter than its predecessor.

In episode, Zipp Design Engineers Ben Waite and John Leachman explain all that’s new with the 858 NSW and 808 Firecrest. They detail Zipp’s development and testing of the new wheel, talk about its carbon construction, and give practical tips for riders making the transition to Zipp tubeless and hookless wheels.

Edited Excerpts

Zipp Senior Design Engineer Ben Waite on the new 858 NSW

A lot of our huge technology breakthroughs that we’ve had on the 353 tubeless straight-side (hookless) and then the 454 tubeless straight-side wheels, took and applied to the 858. Some of our manufacturing techniques and designs allow us to drop a lot of weight while still maintaining our strength and durability.

The physics does show aero over weight when it comes to time trialing and triathlon. Now, it’s not aero over weight—you get both.

The goals for the project were to drop all this weight, and the tubeless straight-side (hookless) compatibility and maintain the same aero performance as our previous 858 NSE, which leads in its class. Whenever we chose a 23mm internal width, that determines what our external width is—27mm. The previous 858 was a lot narrower. Our frontal area increased. But because of the tubeless straight side and its interaction with the tires we were able to maintain the same aero properties as the old one or improve a bit.

We’re moving from the days of 21 and 23mm tires where everybody is going to be riding 28mm soon and we may settle out on 30mm, even on a time trial bike. With that larger tire, larger volumes, you can run lower pressures to decrease rolling resistance and still maintain your aero properties and end up much faster than you were before.

Zipp Senior Design Engineer John Leachman on the new 808 Firecrest

The 808 Firecrest is for road riders and road race specifically, as well as triathletes and time trialist. We wanted to get this back to a crit wheel. A lot of people saw the 82mm depth as heavy. That was a big target that the product manager pushed out to us, that we need to get the weight down. We need it to be stable, we need it to spin up fast. It’s a great triathlon wheel. It’s got the aerodynamic efficiency. You could pair it with a disc wheel, no problem. But you could turn around and take it to a road race.

We decreased the depth to 80mm from 82mm. The big thing that stood out when we did that was stability. At a 10-degree yaw, it has less side force. So, it’s an easier wheel to ride, easier to handle, performs better in gustier situations. The gains we get from increased stability as well as larger tire size and lower tire pressure, we’re faster as a total system.

We have over 14,000 miles in test riding in the field. Ride characteristics are still big and something we want to understand better. The stability in the wind tunnel is great, but I didn’t have a great feel for how that translates to out there (on the road). It gives me an opportunity to validate numbers I see in the lab. What I’m looking for is feedback from them like, ‘it’s a little gusty, a little windy, and it’s pushing me around,’ or ‘hey, I was riding through crosswinds and these feels felt great.’ I saw that one come through quite a few times from both (808 and 858) of our reports… It gives me much more confidence in the data that I get that it applies to real-world situations.