An Afternoon With Zipp
This week I got a visit from Zipp’s head of marketing and media relations. He stopped by with examples of their new designs, in particular, the new Firecrest 808s and the carbon clincher 404s, which also benefit from Zipp’s new Firecrest rim shape.
You’ll find below this post my belated review of the previous iteration of the 404 in tubular form. It is unequivocally the fastest wheel I had ever ridden. Well, it used to be. I’ve ridden the 808 and it, well, I’ll get to that.
Deep-section carbon fiber wheels all have a “V” shape in cross section, that is, except for Zipps. The 404s I’ve been riding employ a hybrid-toroidal shape that makes them both faster and easier to handle. The new Firecrest shape doesn’t really look fast when viewed in cross-section. It looks rather fat and not exactly fast. Looks are often deceiving.
Not only is the Firecrest shape faster, it adds stability in a cross wind and increases rim strength for impact over rough road (or pavé). The most surprising aspect of the Firecrest shape is how Zipp engineers were able to tune the shape in the 404 and 808 so that the center of pressure, that is, the focal point of a cross-wind’s pressure on the rim was not only near the steering axis, but slightly behind it. The thrust here is that a cross wind from the rider’s left didn’t push the rider to the right, but rather ever-so-slightly steered the rider left and into the wind, making these wheels stunningly stable in a cross wind. To ride the 808′s stability in a cross wind is to know the meaning of unlikely.
Total claimed weight on the 808s is 1519g. That said, there’s a fair amount of carbon that constitutes rotating mass. Even though the wheel is reasonably light, I wondered just how easy it would be to accelerate. What surprised me was they were as easy to accelerate as any of my lightweight clinchers.
The wide rim bed (25.94mm front and 26.24mm rear) gave the tires an ideal platform to retain their true tubular shape. Cornering on a twisting descent on the 808s was Cirque du Soleil-nimble. Brake response was decidedly even and smooth, but one small word of warning: This rim shape is very wide. Brake set up and brake shoe position are such that you won’t be able to swap other wheels in or out for the 808s without taking some time to adjust both the brake and the brake shoes.
This was but one ride and Zipp has more patented and trademarked technologies that I’ll go into later when I’ve had a chance to ride these wheels in greater depth. My initial sense is that the new 808s are the fastest wheels I’ve ever ridden by a couple of country miles.
Zipp 404 Wheels
Author’s note: I began a review of the Zipp 404s in late 2009. Along the way, I ran into a few issues with the wheel and took my time getting answers and assistance from Zipp. My mistake. Within days of being ready to run the review, Zipp announced the new Firecrest rims as well as other changes to the design of the 404s, including a new all-carbon clincher. I shelved the review until I rode the new Firecrest 808s this week and realized I needed to post this review as a prelude to what I’d say about Zipp wheels in the future.—Padraig
My experience with Zipp products goes back 15 years. In 1996 I rode a set of Zipp 440s, which are analogous to today’s 404s. They were ungodly stiff, had the menacing sound of a carnivorous machine and a fiberglass braking surface. The Dura-Ace brake pads bit down as if the bike was equipped with disc brakes; I actually slid forward on my saddle the first time I hit the brakes. I hated the brake response so much it clouded my opinion of the bike they were on; I plain didn’t like riding the wheels, no matter how aerodynamic they were.
A few months later I had the pleasure of reviewing the Zipp 530s, which were essentially the same wheel in clincher form with an aluminum braking surface. When I say pleasure, I mean that I loved the wheels so thoroughly I didn’t want to send them back. Yes, they were heavier than the 440s, but a less-than-1600g set of aerodynamic clinchers was all-but unknown in 1996. The combination of unchanged brake response, decreased weight (relative to other clinchers), the ease of changing flats with clinchers and improved aerodynamics struck me as the proverbial unbeatable combination.
In my review I noted that I weighed the wheels without skewers, tires, tubes and cassette. The accompanying reviews in our roundup of carbon fiber wheels didn’t note that and as a result, Zipp’s founder, Andy Ording, got the idea that readers would believe that only his wheels had be weighed that way, potentially creating the impression that Zipp wheels were heavier relative to the competitors’ wheels. His follow-up phone call resulted in an extra body cavity for me. With friends like me, he reasoned, he didn’t need competitors.
I’m not sure anyone came to the conclusion he feared; it required a leap of illogic more cynical than most bike geeks would make. Regardless, the call left a lasting impression. While I felt badly that he believed my review resulted in a less favorable presentation than I intended, I was more impressed by his passion. Ording was a guy who simply wouldn’t tolerate being outdone.
Wind tunnel testing and composites engineering are present-tense advertising bywords. You’ll find them in copy from Specialized, Cervelo, Felt … and Zipp. However, those were bywords common to Zipp (and almost no one else other than Kestrel) in the 1990s. So long as Ording had any say in it, there would be no wheels lighter and more aerodynamic than Zipps.
We’ve all heard of the now-famous Kona Count. Every manufacturer goes to Ironman Hawaii and counts just how many athletes have spent their kids’ college tuition on their gear. Kona is the canary in the coalmine of triathlete purchase trends. Spinergy, once one of the most popular brands among triathletes, now has a less than 1 percent share of the wheels at Kona. And Zipp? More athletes purchase their wheels than all other brands added together.
There’s a reason why an amateur athlete will spend more than two grand on a set of wheels: They are fast. Damn fast. In a sport full of agonizing decisions, Zipp is the no-brainer answer to fast wheels.
For me, it had been a while since I last rode a set of Zipp wheels for more than a day or two. I had a few days on a set of 202s and they were sweet enough to fill my head with thoughts of larceny, but it had been nearly ten years since I’d last done a dozen rides or more on a set.
The 404s I’ve been riding were the latest and greatest for 2010: ABLC dimpling to make them slice through the wind faster than a speeding golf ball, tubular construction for the lowest possible weight, Carbon Bridge technology and the VCLC system to increase impact resistance while cutting vibration transmission. They also roll on ceramic bearings. Prior to glue, tires, skewers and cassette, the wheels weighed a measly 1238 grams. I’ve had meals that weighed more than that.
If we take Zipp at their word that they have devoted more than 100 hours of wind tunnel time to the 404, testing its response to the wind blowing from 0 to 30 degrees (broken down in five-degree increments—that’s seven different angles), that’s six figures of development cost right there. If there is a more thoroughly researched wheel on the market, I’d like to hear about it.
In riding, several details of my experience made the bulk of my verdict about the wheels. The critical factors were speed, weight, braking performance and even sound.
Speed: There’s no way to tell where the increased speed due to aerodynamic factors stops and reduced friction from the ceramic bearings starts. The combination of the two made the 404s quite noticeably the fastest wheel I’ve ever ridden. Cynics, take note; my assertion isn’t just lacey language. While I could do nothing to override my impression of instant adrenal power, I have several objective factors to back up my impression. I made a habit of taking my HR up to 155 on these wheels and with other wheels. I consistently rode 1-2 mph faster with the 404s. Even more apparent was the way the wheels rolled when coasting; when coming up to turns in a group I found myself needing to brake earlier and sometimes more firmly than usual because I was running up on the rider in front of me. Add up the reduced rolling resistance of the clinchers, the improved aerodynamics of the rim and the reduced friction from the ceramic bearings and these wheels just rolled and rolled.
Weight: As I mentioned, my set of wheels with no skewers, tires, valve extenders or cassette weighed just 1238g. Lighter wheels exist, but the combination of F1 aerodynamics for high speed and ballet dancer weight for long climbs makes me think I can eat the cake I keep.
Braking performance: Using the Swiss Stop-made Zipp brake pads, I found the brake performance to be the most even of any carbon fiber wheel I’ve ridden. On every other wheel I’ve ridden the pads will grip more firmly on one part of the rim. This inconsistent brake response is disconcerting and has the ability to cause heat buildup at that point on the rim. I’ll address that particular problem—and its ramifications—in another post.
Sound: Some bikes sound as cool as they look. The 404s are the only set of wheels in the sub-60mm rim category that impart some of the sound of a disc wheel. The white noise whoosh a disc makes has always given me an electric surge and the 404s include a dash of it, kinda like the packages of hot sauce you get with your burrito.
Okay, now for the downside. No, I’m not talking about the $2285 price tag of the tubulars with ceramic bearings, I’m talking about the aspects of these wheels that weren’t grand-slam perfect. These wheels are so close to ideal, both you and the folks at Zipp deserve to hear about the wheels’ few blemishes.
Rim balance: With the aluminum (not brass) valve extenders attached to the tires’ valves, I experienced a noticeable weight imbalance. Out on the road, a noticeable pulsing feel emerged at speeds above 30 mph. It was a little disconcerting on descents. Even when I added wheel magnets to opposite spokes, I couldn’t completely overcome the weight imbalance; the valve extender always spun to the bottom of the wheel when the bike was in the stand. When I asked the folks at Zipp about the phenomenon, they said they had two choices and they chose the lighter wheel and believe their customers prefer it that way.
Spoke tension: I had two spokes on the rear wheel detension to a significant degree within the first 400 miles of riding. I don’t know the cause, but I suspect the spoke tension was not ultra-consistent around the wheel. After so many flawless miles on Easton wheels, I have come to expect wheels that stay true over a longer term. Proper spoke prep and even tension shouldn’t be an issue with these wheels, but I was able to correct it without rebuilding the wheel.
Creaking: I had a devil of a time tracing creaks in both the front and rear wheels. They creaked from the first mile. Getting this corrected took months of fiddling.
The Zipp 404 is the best all-around wheel I have ever ridden. Full stop. The technical term for this is funfunfunfunfun. These wheels are a benchmark by which I can measure all others, the Muhammed Ali of wheels. Perhaps this is the assessment Ording had hoped for all those years ago.
