It’s November, and the last thing we expected was a new product launch. Typically when we get past Kona we get a little time off until new launches being with the start of the UCI calendar. But it seems that 2016 is a bit different, and Zipp had other ideas. And lest you think this is just the same thing in a different size – the fact that this wheel ditches the 0 nomenclature for 5 should give you a hint that this is special. Meet the Zipp 454.
The Zipp 454 NSW Carbon Clincher
The 454 looks a little different than the wheels we typically find in transition. And to get that shape, Zipp started not with CFDs and clay models, but with biomimicry – the imitation of the models, systems, and elements of nature for the purpose of solving complex human problems. Previously, this technique had been utilized in aviation, motorsports, energy production, and other industries. Zipp decided that cycling was where it belonged next.
It took 4 years in development, 36 prototypes, and 252 hours in the wind tunnel to create the final 454 shape. The Sawtooth rim shape takes the Sawtooth dimple design we saw on the original NSWs and applies it to the entire rim shape. The result is a rim shape that takes nature’s most elegant design solutions and combines engineering precision to deliver a wheel that performs unlike any made before.
The Hyperfoils (nodes) stabilize the wheel in gusty conditions by increasing vortex shedding frequency.
The new Hexfin ABLC dimple pattern increases boundary layer mixing to help keep airflow attached to the rim. While the fin-shaped clusters made up of variable sized dimples work in concert with each HyperFoil.
Like previous NSW wheels, the 454 features the showstopper brake track. Showstopper adds directional, molded-in, texture paired with silicon carbide (SiC) particles suspended in the surface resin. SiC is nearly three-times harder than hardened steel, which helps ensure a strong and consistent braking experience. The grooves on the wheel also help to wipe water away and act as cooling vanes.
The hubs are Zipp’s Cognition hubset with Axial Clutch technology. Every time a conventional hubset starts to coast, friction within the freehub ratchet mechanism works like a drum brake to slow the rider down. With Axial Clutch, the ratchet mechanism is disengaged when coasting. It then uses magnets to re-engaged once the rider starts pedaling. The goal is to allow you to hold your speed longer as you hit the turnaround point.
The 454 weighs in at 1525g for the total wheelset (690g front / 835g rear). Final rim depth ranges from from 53mm to 58mm with a max width of 27.8mm. Oh, and the cost – $4,000 (yeah, you did read that right).
Why _5_?
So why the new shapes and technology? Amazingly, it’s not just for speed. Zipp tells us the 454 will save you 2 watts from 0 to 12.5 degrees yaw and at 15 degrees or greater is anywhere 5 to 8 watts compared with 404 Firecrest. But thats not where these wheels were made to perform. The 454 is meant for the cross winds.
Zipp tells us the 454 has lower total side force, reduces variation in cross wind, and moves the center of pressure when compared to competitor products.
Our Thoughts
It’s hard to deny that $4,000 is a lot of money – especially when you consider that, from a performance perspective, we are talking just 5-8 watts when compared against an 808 Firecrest at high yaw conditions. But for those that spend time in cross winds (aka KONA) competing not just for podiums but for AG and Pro World Championships, we suspect these wheels will have a definite appeal. We are really looking forward to getting these on US-27 down here in South Florida to see how they handle the winds and if reality matches up to the claims. Stay tuned for our in depth review!
Inspired by the humpback whale, apparently. It’s not clear to me how the sawtooth design is inspired by the bumpy fins the humpback whale has to reduce it’s drag in the water, but I admire their willingness to try new things.
However, it does raise the question of whether Zipp has literally gone off the deep end by trying to design a wheel in this way. I’m wondering if their attempts to innovate will pan out with this one.
CFD analysis does not work well when modelling turbulence, which is the main means by which this is supposed to work. They claim to have made 36 prototypes and over 200 hours in the wind tunnel.
So … It would help a great deal if Zipp had published drag results relative to their existing 404 NSW or 404 Firecrest models. I wonder what the drag differences would have been, or if indeed there are any.
Exactly. And all these months later and not even Zipp have backed their own claims. Speaks volumes about how much they can justify the price and design.