Zipp 404 Firecrest Carbon Clincher

 I’m going with Zipp’s images here because my shots didn’t do them justice.

Plot spoiler: These are the finest wheels I’ve ever ridden in my life.

There. That’s out of the way. Now that I’ve eliminated any sense of drama from this review, I can get down to the matter at hand and discuss the experience of riding Zipp’s standard-bearer wheelset.

There’s an arms race in cycling that’s been escalating over the last 10 years. I think back on the most I could spend on a set of wheels or even a whole bike 10 years ago versus the colossal $2700 that these wheels go for and I choke. There’s nothing else in my life that has escalated as badly over that time, save the housing market and we see what happened with that. Somehow, I don’t see Zipp, HED or Lightweight wheels suddenly dropping in both price and value—not now, not in the future.

The math on this is difficult to avoid. For that much money you could outfit an entire Girl Scout troop with iPhones. Or you could provide the entire U.S. Army with bubble gum. Or you could purchase a single set of wheels that would do more to improve your performance than an extra two hours of training per week can.

Oof.

These wheels are so sophisticated I could probably write about them for the rest of the week and not divulge any of Zipp’s trade secrets. The 404s possess three distinct features that have caused me to come to the conclusion I did.

First and foremost is the Firecrest rim shape. While I am aware that one of Zipp’s competitors claims to have arrived at the rounded rim profile at the same time as Zipp, the fact is when Zipp came out with Firecrest at Interbike in 2010, their competitors talked crap about the silly shape. The trick to Firecrest is that it treats the half of the rim behind the axle as a leading edge and that blunt shape improves the rim’s aerodynamics dramatically. The most surprising aspect of this is what is called vortex shedding.

Those of you who have ridden deep-section carbon rims and been buffeted by the wind have experienced vortex shedding. Every time the airflow attaches to the rim surface and then breaks free from it the wheel is buffeted and you feel it at the bar. That’s not even the most dramatic feature of the Firecrest shape. This is:

It’s more stable in a crosswind.

The rim shape causes a change in the wheel’s center of pressure. It’s a crazy term for the point of leverage the wind has on a wheel; it’s a very east-to-feel phenomenon. Ride a deep-section wheel in a crosswind. If the wind is blowing from right to left, you’ll be steered to the left. That’s because the center of pressure of most wheels is forward of the steering axis. Firecrest, on the other hand, shifts it almost in-line with the steering axis. Ride a Firecrest wheel in a crosswind and you’ll feel almost no pressure on the wheels. It’s a bit more complicated than that, as the way a rim sheds a vortex changes slightly as the wheel spins; the center of pressure can actually shift behind the steering axis slightly, steering you into the wind instead of pushing you across the road. It’s a remarkable sensation and results in a real increase in confidence compared to riding other deep-section wheels.

How good an idea is Firecrest? Well, after bagging on it as crazy, both HED and Enve have moved all their wheels in that direction. And while competitors may be trying to emulate the vortex shedding properties of Firecrest, they can’t copy the golf-ball-like surface of the ABLC (Aerodynamic Boundary Layer Control) that keeps the air moving by the rims.

If you were to buy a set of 404s for only one reason, Firecrest would be it. No other deep-section wheel I’ve ridden is as stable as the 404 Firecrest.

The Carbon Clincher technology is my next most favorite feature of these wheels. The time I spend in Malibu riding with friends means I’ve either personally melted or seen melted wheels by every manufacturer except Zipp and Easton. Last summer a small group of us did the now notorious descent of Las Flores Canyon. I rode the 404s and didn’t have a bit of trouble, despite some firm braking at times. After reaching the bottom I waited more than five minutes for a friend to arrive. He was concerned his ultra-zoot wheels from a certain German manufacturer would melt, so he stopped three times to let them cool off. Granted, this guy weighs a good 30 or 40 pounds more than I do, but if you can’t take a mountain descent on a set of wheels, what good are they?

Other than the fact that they don’t melt—which is reason enough to take note—they do have one other detail that make these clinchers pretty killer: The rim width. Roughly 25mm wide, any clincher you mount on these wheels can be removed with no tire lever (sweet) and gives the tire a much wider footprint, increasing traction without—I’m told—increasing rolling resistance (amazing). There is a however, here, however. Setting up brakes for a rim this wide isn’t easy and you have to adjust the brake shoe angle because of the angled braking surface. Swapping out these wheels for another set is going to result in at least a half hour of work, if not more.

The wheels’ next best feature are the 88/188 hubs. They are an improvement on the previous iteration of the hubs with which I experienced near constant creaking. Really effing annoying. These are stiffer and don’t creak. What is more impressive is how these things roll. Zipp uses grade 10 ball bearings in the hubs. That is, they are accurate to .10 of an inch. That 2.5 times as round as the grade .25 balls used in Dura-Ace and Record hubs.

You may not think that’s particularly impressive, but I can say from experience that when I’m inside a group, the combination of superior aerodynamics and fast-rolling hubs causes me to hit my brakes to modulate my speed because I begin rolling up on riders in front of me when we’re coasting.

My set weighed in at 1562 grams, just a couple grams off the advertised weight. I’ll call it even. The combination of aerodynamics and weight mean that they are not only killer on the flats, but they are light enough to be reasonable climbers.

Engineers at two different bike companies told me off the record they have taken a number of wheels to the wind tunnel to test with their TT bikes. Both said that tire choice has a huge effect on aerodynamics. Even so, both also said that no other wheels they have tested are as versatile as the 404s.

Here’s the strange thing I’ve noticed about riding with the 404s. While I have many friends who will train on heavy wheels and save the good stuff for race day, in reviewing these wheels, I didn’t have that luxury. I needed to get miles on them right away. Oh, and I’m not really racing, so there’s that, too. With the addition of the 404s, the increase in aerodynamics gave me enough of an edge that I was able to get to the front of the group rides more easily. That, in turn, gave me the ability to stay at the front more. The upshot may seem counterintuitive; the wheels didn’t make the ride easier for me. They made it easier for me to get to the front and flog myself more, rather than sitting in the pack just trying to hold on to my spot. It seems I train harder with faster wheels.

Honestly, suffering more—not less—is the last thing in the world I expected to have happen.

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15 comments

  1. Ghost Rider

    You’re several orders of magnitude off in your discussion of bearing “accuracy”…for a grade 10 bearing, sphericity variation is 0.00001 in, while a grade 25′s variation is 0.000025 in. That is a TINY difference.

  2. Cleave

    Hi, so the brake adjustment issue kept me from buying these wheels last year. If I win the lottery and switched all my wheels to Zipp, are all of the Firecrest brake surfaces (303, 404 clincher and tubular) the same? Thanks.

  3. A Stray Velo

    In my personal experience I’ve found that rim width is one of the biggest factors in determining a nice riding wheel or not. I’m glad we can add Zipp to the list of manufacturers spec’ing wider rims on factory built wheelsets.

  4. chad

    I have to agree with Padraig; earlier this year I rode a set of the 404 clinchers on a disk-brake Crux in all sorts of windy conditions, up and down big road climbs, and on trails ranging from slightly rough to downright cobbled — and the 404s were a transforming experience, just spectacularly good.

    However, I probably wouldn’t race Cx on the clinchers. Still too easy to flat; they’re still clinchers after all. But as road wheels — wow.


    1. Author
      Padraig

      Cleave: So I checked with Zipp and they say while you may have to adjust the throw a little bit, pads adjusted for the 404s will work with the 303s or the 808s. So at least there’s that.

      Noel: You know me better than that. If I look like I’m flogging myself, I am.

      A Stray Velo: Yeah, I’m with you. I’m really over skinny rims and love having more rubber on the ground on a descent.

      Jeremy: Good point. I suspect there’s a GAO report that shows $2700 would only buy you half a pallet of Trident.

      Chad: I gotta say, I don’t understand the desire to run carbon rims (even tubular) on a ‘cross bike. I always want stuff that is just ultra-bulletproof, and that’s not to say that Zipp rims aren’t strong. They are.

  5. velomonkey

    ” Or you could purchase a single set of wheels that would do more to improve your performance than an extra two hours of training per week can.”

    There is no possible way you can qualify this statement. This is not a product review, it’s marketing language made for sheep (which I think you authored for Zipp, right).

    I have aero rims and I’ve ridden tons of them including these – yes, they are nice, yes, they will help. They are in no way the panacea that are often made out to be.

    As for riding in a weekly group ride on these wheels – to me it would scream “fred” (your term not mine). But that’s just the velomonkey.

  6. michael

    having purchased a set of the 404 firecrest tubs, all i can say is – WORD. they are my day-in, day-out choice for all my riding on what can charitably be described as the crappy roads i ride on. to say i love these wheels is to say Romeo was mildly infatuated with Juliet. just WOW.

    as for the training harder, suffering more effect – i think it has something to do with an unspoken understanding that if you are riding a PIMP wheelset that you HAVE to be able to back it up somewhat on the road. i`ve certainly noticing myself driving harder and taking much longer pulls than I used to, much to the joy of all those who are riding behind me – until they realize that even though i am 6`1“, my 156 lbs don`t provide much slipstream for them ;)

  7. ben

    To me this product is something I’ll never have. Neat review, but I’m going to re-nombre myself the “dime-bag roadie”. Now if I win the lotto or something I guess that’ll change, but for now and into the realistic future I will be riding/racing affordable aluminum rims in the 500-600$ range.

    I realize that the US cycling market is geared towards dentists and the like (income-wise), but I’m a teacher…married to a teacher…with a family…with a mortgage. Not that i’m complaining about my plot…quite like it actually! Oh well. Thanks for the ripping blog though!

  8. Bob

    I would not be overlly concerned with the brake set-up – I have the Firecrest 404′s and my local bike shop set up my TT bike and my road bike for the Firecrest wheels with enough play to tighten my brakes to work with my standard rims – all I need to do for my standarad wheels is adjust the brake width to be a little tighter – 2 minute adjustment.

  9. Bikelink

    I’m underwhelmed by actual wheel comparison data I’ve seen in the past for ‘super aero’ wheels. I have American Classic 420′s from 2008 (OK, not cheap at msrp 900, but got them with a team deal) and the 2008 ‘great wheel’ test (http://www.rouesartisanales.com/article-15505311.html) showed that the 404s at that time were 10 watts faster at 30 mph. Since 30mph means over 500-600 watts, that’s pretty minimal. So…where is a nice comparison of these wheels vs multiple others at 26mph (nice race pace) that shows they are really worth it? Padraig you have probably a more ‘objective’ bike feel than most, but the ‘placebo’ effect of riding $2700 wheels would probably gives anyone wings…show me the wind tunnel testing…compared to less expensive competitors (what about compared to $600 neuvation carbon wheels, for instance)? (the handling thing in the wind sounds great though). Also, clinchers great for riding, presumably the lighter though similar tubulars from Zipp are ‘better’ (though I’ve never ridden tubulars).

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