Zipp Lead Engineer Josh Poertner

Speed speed speed!

 I recently wrote in a review of the Revolution Wheelworks Rev-50’s that they were "maybe 95% as good as Zipps, for 42% of the price". Soon after I received a "very disappointed" email from Andy Paskins and Josh Poertner of Zipp. Their contention was that a statement like this is very misleading, and was probably doing more to confuse the issue than clarify. Also, the assertion that other brands were less expensive simply because the company spends less on marketing was downright maddening to the Zipp team who point out that they spend many times more money on R&D of new products and new technology than they do on marketing and team sponsorship combined.

I responded that I’d tried for months to score an interview with lead design engineer Poertner to no avail, and had been more than eager to get Zipp’s side of the story. Soon after I scored my Poertner interview, complete with his assurance that all issues were open for discussion.

As it turns out, Poertner is beyond loquacious, even by our standards. So what follows is a combination of direct quotes and paraphrasing, hopefully with no punches pulled despite the fact that Zipp have been one of our staunchest sponsors.

Zipp vs Asia

First we discussed the difference between Zipp and a company like Gigantex, the Taiwan based carbon manufacturer.

A rim like a 404 or an 808 has "about 150 wind tunnel hours at 900 bucks an hour, plus travel time, plus rapid prototype costs, from a clean sheet of paper to a finished product like the 808, probably on the order of a half million dollars. Between wind tunnel hours, R&D, development just on the rim shape, and all the parts you have to build to prove out the laminate, the layup, the testing, the safety testing, ride samples, ride testing… By the time we cross the finish line on that you’re well over half a million bucks in the hole."

By contrast, an Asian manufacturer can take that rim, "and in three days you can have almost the exact rim shape copied. The carbon won’t burn but the epoxy will, so what they do is they have these ovens that cook the rim at 800 degrees, and all the epoxy burns off and the layup’s exposed…my half million development cost to get there the first time, plus 12-14 months, is probably backed up on their end by maybe 30 days start to finish, somewhere on the order of probably 12 to 15 thousand bucks."

The upshot is that Gigantex can create an a la carte menu of rims. Anyone can walk in, pick and choose from a list of options, and be up and running as a wheel company in a very short time. I asked Poertner that if this was so, why would someone buy a Zipp instead of knockoff.

"Firstly, I really see us as developing a wheel system. The rim, hub, spokes and nipples are specifically designed and manufactured to function together as a system. So the hole drilling in the rim and in the hub are matched to actual spoke angles, every last gram of weight can be carved out of the hub if you know exactly how it will be used, every detail of the layup can be tuned to actual spoke count and stress. Look at our hubs for example, nothing in the industry is close, we are running some of the lightest weight hubs, with the largest and widest flanges available, combined with the largest axle used in any road hub for added stiffness, proprietary bearings from Switzerland designed specifically for this application, and you have something really special that you aren’t going to get picking off the shelf parts from a vendor catalog.

Ultimately we are perceived as a product company, but at our core, we are a technology development company that does killer product. I really see our place in this industry, as the guys who are driving full speed ahead on both product and technology development with a cost no object attitude, trying to find that next advantage for our customer, and trying to advance the technology as a whole. I think there’s a customer base out there that’s willing to pay for that next incremental advantage, and to pay to have the latest greatest technology available. Our target customer base is the customer to whom the product itself and the experience in using the product is greater than the incremental cost over our competition.

…at our core, we are a technology company that does killer product.

This is true with everything, look at cars, motorcycle, camera equipment, stereo equipment…all of these industries have technology leaders who disproportionately advance the whole industry through their innovation, and these companies are selling products that are expensive compared to much of the rest of the industry. When you are a commodity focused company, your focus is on cost reduction, or at best on the cheapest possible way to add a technology that the customer demands, but when you are a technological leader, your focus is on achieving the next incremental advantage, improvement, or additional functionality and THEN determining if it can be fit into a cost structure that people can afford. The other interesting angle on this analogy is that the technology leaders in all of these analogous industries are also never the most expensive option, that is always reserved for brands that offer fashion and exclusivity over being the most technologically advanced…and that is completely true in our industry. At $2285, a set of Zipp wheels is very expensive, but when you consider the playing field, I would say we are a bargain. There are more than a dozen wheelsets on the market priced over $3000 and none of them can offer improvement over the competing Zipp wheel of similar depth. A European magazine editor told me a few months ago that they were shocked to see us win their stiffness, bearing drag and aerodynamics categories when they thought we were mainly an aerodynamics company. All in all, we were in the top 3 of every single category, and wheels in the test ranged between $1500 and $10,000, so we were below both the mean and median price for the test."

Poertner cites as an example of that cost no object attitude the fact that the 404 rim is in its 6th iteration in 7 years, the 808 in its 3rd in 5 years. He says that Zipp will continually push forward in ways they hope their competition aren’t willing.

Next I asked Poertner about the 404’s new curved brake track, a carry over from the 808’s.

"Yeah, we’ve had good luck with that. That’s a good example of a great Zipp product story…when you really think about it, the curved brake track presents some issues on the manufacturing side, like "how do you measure that for quality control?" A straight sided rim, you just put calipers on it all around. But a curve, how do you measure a complex curve rotated about a central axis without a coordinate measuring machine? We developed that concept for the 808 in ’03 or ’04, it was probably ’05 before we developed the really good generation of QC. Now the rims that come off, they’re all QC measured by a robot. That, to me, is the essence of Zipp technology. It’s a real, measurable, quantifiable improvement in the technology behind the product, as well as in the product itself, as in the end, the new rims have better brake modulation and better wet performance as well as superior aerodynamics. The dimples on the rim were a similar story, the product concept existed for 2 years while we developed the technology to manufacture the molding tools to actually make the rims. We always say that anything worth doing comes at such an insanely high theshold of pain, but it’s worth it.

We had to suffer like beaten dogs to figure this out, so anyone who wants to follow us, they have to figure it out too. You can do curved brake track and not QC it, but man, you get killed. Designing and engineering is a lot like bike racing. It’s not necessarily the guy who’s straight up strongest, it’s the smart, tactical guy who can suffer the most for the longest who gets the big wins. That, to me, is what makes Zipp technology special, we develop every level of technology from the product concept, to the production and tooling technology to the quality control and measurement technology to make it possible. The whole process is vertically integrated in one building and we control it all"

Zipp vs Mavic

When questioned about the competition between Zipp and Mavic, Poertner points out that the companies are really focusing on two different pieces of the market. The story of Mavic wheels is all about weight and rotational inertia, while the story of Zipp wheels is focused on aerodynamics followed by weight, inertia and bearing efficiency.

"The more you look at inertia, inertia’s just a second order phenomenon. It’s just not that important. Aero is THE primary factor of wheel speed. It’s not weight, it’s not inertia, it’s aero. Everything else is obviously huge in terms of nuance, but weight will save you a watt or two. Inertia will save you a fraction of a watt to a watt. Aero will save you 40 watts at certain speeds. It’s huge to go from a wheel like an R-Sys to a wheel like an 808 clincher which is a pound heavier, but it’s about 50 watts more efficient at 30 mph. But of course the problem is in the consumer’s mind, 1350 grams vs 1680 grams, that has real tangible meaning to people. Arguing about inertia seems tangible to people because they’ve always heard that weight is important in wheels because it hits you twice. There’s just nothing tangible about aero."

I asked Poertner about the fact that aero benefits are hard to quantify and easy to spin. Many makers of aero wheels will cite wind tunnel data that claim their wheels are the fastest.

Mavic is about weight and rotational inertia, Zipp is focused on aerodynamics

"Yeah, that’s the game. One, aero testing is so expensive no one really wants to do it, and in the US media, that’s too much of a political hand grenade (Ed: to declare a definitive ‘winner’ won’t make you popular with your advertisers). The only guys worldwide that I see doing legit wind tunnel testing is Tour Magazine in Germany. Every year Tour Magazine takes a whole bunch of wheels to the tunnel and publishes the data. The good news, for us, is that every year we win that test. So in markets where that testing is done and the data exists, it really plays in our favor. Even then, testing can be misleading, a company can take a single data point where they are strong and spin it into an entire marketing campaign, or a magazine test can run wheels at zero degrees yaw in the tunnel and come up with ‘the fastest wheel’ without disclosing that the condition they were testing for is a pretty low probability condition, but nobody wants to print ‘the fastest wheel 4% of the time’

The other thing, the one factor that’s been more beneficial to our company than any other is power meters. You can SEE it, especially if you’re willing to parse the data, you can run your own component testing with power meters. That wattage forum at topica, or slowtwitch on the triathlon side. Andrew Coggan, the wattage gurus, who are actually doing power measurements and publishing data. That’s good for us, too, ’cause we always do well."

Ceramic Bearings

Zipp stumbled onto ceramic bearings while building wheels for Jan Ullrich’s 2000 Olympic effort. A college friend of Poertner’s was making incredible ceramic bearings for the Space Shuttle, and a connection was made.

By 2001 the Z series of wheels were launched, complete with ceramic bearings. Today, the buzzword ‘ceramic’ is the fastest growing ‘brand’ in all of cycling, but a very misunderstood one.

The reality is 90% of the ceramic bearings in cycling were never meant for this type of use.

"The reality is 90% of the ceramic bearings in cycling were never meant for this type of use. Why do ceramic bearings exist? In 90% of the world it’s for heat. You get these cheaply made bearings that people put in parts that get hot, ’cause you don’t have all the thermal expansion issues that you get with steel. Now you put them in a bike hub, and next thing you know, you’ve got Zipp customers complaining that their hubs feel terrible or their bearings broke, or their races are pitted or cracking. Suddenly the customer has a ‘hub’ problem. Well, we’ve never heard of a Zipp bearing ever fracturing, it just doesn’t happen. Then we come to find out, ‘I spent $200 on Brand X bearings, so it must be your hub shell that’s doing that! ‘Cause these are CERAMIC!’

So in reality, the customer has now spent 200 bucks to downgrade their bearings two levels in quality, and have a failure. It’s pushing a boulder up a hill at that point. ‘Ceramic’ is a stronger brand than Campagnolo in terms of quality and inability to do wrong to the customer. We see that all the time. Our #1 hub related warranty complaint is issues encountered after non-Zipp ceramic bearing ‘upgrade’. It just goes to show you the prevalence of that. Just looking at that complaint data, probably 5-10% of our customers are ‘upgrading’ to ceramic?? And almost every one of those people is putting in something significantly worse than, or at best something equal to our stock bearing. Meanwhile, the standard Zipp bearing is the only bearing in the industry sourced from Switzerland, uses the same ABEC5 races from the same factory as the CeramicSpeed ceramic upgrade for Zipp (a $750 bearing upgrade) and at $125/set costs as much or more than most ‘ceramic upgrades’."

Zipp vs Hed

Steve Hed, who jointly holds the toroidal rim patent with Zipp, once told me that Zipp hates him because they just can’t get their rim shapes right. He says that while Zipp rims can produce a gaudy drag number at one yaw angle, Hed rims perform better over a wider range of yaw angles.

For Poertner, this anecdote garners a smile and a note that while the companies jointly hold the toroidal patent, before Zipp introduced the 808 in 2004, neither company produced rims of this shape, and that before the 808 ventured to be 28mm wide, neither company was making super wide toroidal rims that are now the staple of both companies. He also points out that over the last few years the Hed rim shapes and wind tunnel data have started to look an awful lot like Zipp rim shapes and Zipp data. Poertner also points out that Zipp was the one to develop the theory of real world wind angle probability and then set out to develop rim shapes that worked best in the conditions experienced most frequently.

…what we’ve done is optimized and designed our rims to work at the angles you are most likely to experience on the road in the real world.

"Steve really believes that wind angles tend to run higher than lower. You can go to the Hed site and there’s a wind angle calculator. Here’s the rider and his direction and his speed, here’s the wind and its direction and its speed, and you can calculate that instantaneous wind angle. Now, to me, what’s that given you, that’s how you determine the max wind angle on that day, and there’s a simple hand calculation for that, the inverse tangent of the wind speed over the rider speed.

So if you’re riding at 20mph, and you have a perpendicular wind speed of 10mph, that yaw angle is 26 degrees. So the way he looked at it is to say, ’10mph is a common wind, 20mph is a common rider speed, so 26 is the wind angle where we need to work’. The way we worked at it, and this is based off a headtube mounted yaw probe that we built 6 or 7 years ago combined with mathematical modeling, was to say that’s the case when the wind is exactly perpendicular to you, but the road turns, the rider turns, the wind changes, the wind speed at the ground isn’t necessarily the same as where it’s higher, so there is so much more to the story than the 26 degrees..

You talk to the weather service and they’ll tell you that average wind condition at any given time during the day is about 8mph in some direction. Well, that’s on a weather service pole, a 3 meter pole. So you’re probably a touch slower at the ground. But even at 8 or 10mph, how often are you riding an out and back where the wind is perfectly perpendicular to you? So we started to determine true wind angle probability of occurrence. What you find in most circumstances is you get a bell curve with zero and max wind angle at the two ends. (Actually the zipp model is two bell curves running from –peak angle to +peak angle with 0 in the middle, and 2 small bell curves, but for simplicity is depicted as just being 0-peak angle and a single curve). In the more modern era we do this with GPS where we can plot actual rider speed and direction and overlay the wind data from the weather service…this allows us to plot the exact distribution of wind angles, and we continue to find that the data matches the original model we discussed in our white paper on this back in 2002-2003.

So back to Hed. He’s in the camp saying 26 degrees, and we say 26 is the max, but if I run that and plot the curve, 13 is the most likely, it’s the highest probability. So that’s where we really diverge. What we found, and we backed it up with this headtube mounted probe that we rode the heck out of and collected the data for months, real world wind angle probability falls between 7 and 15 degrees. If you’re slower it runs higher and vice versa. It’s very rare that you’re going to have a most likely wind angle of 20 or higher, ’cause that means your peak wind angle is going to be 40 or more, and to get there you either have to be going really slow, or have really ridiculous wind speeds, at which point most people are going to opt for shallow wheels.

So the way Steve calculates really works favorably to the 3 spoke wheel, ’cause that wheel is pretty average ’til 20 degrees, then it’s super fast between 20 and 35. So that works really well to say, ‘Hey, you’re an age group triathlete, run this wind angle, you’re going to be in the 20’s, and this wheel going to be the fastest in the 20’s.’ The way I look at that, looking at the wind angle probability, that same age grouper that he’s considering at 26 degree yaw, we are considering, by the first deviation, is going to be roughly between 9 and 17 degrees. And that’s a whole other story, because between 9 and 17 degrees there’s a whole host of wheels that are a lot faster. So, with our rim shapes and our wind tunnel testing, what we’ve done is optimized and designed our rims to work at the angles you are most likely to experience on the road in the real world.

Designing a rim is like designing an aircraft wing, right? With enough time and enough money we can make it optimal wherever we choose. And we believe this more reality based statistical probability model of wind angle, we really shoot to be peak efficiency between 10 and 15 degrees, and have your peak minimum drag in that range. And I think the reality, the GPS data, the teams testing it, the power measurements off the bike, time seems to be proving our picture of wind angle probability to be more correct. And I would say the market is rewarding that, the pro teams are definitely rewarding that. Six teams in the Tour were using Zipp products this year yet Zipp lists only 3 official team relationships. We work with the teams that are doing the testing, that are interested in technology, the ones for whom the data and expertise we bring is worth more than the money other companies can offer."

Backstedt at Paris Roubaix

Speaking of working with pro teams, I asked Poertner about the PR fiasco that was Magnus Backstedt’s Paris Roubaix of ’08, where he broke both his 303’s and DNF’d.

"The Backstedt incident was brutal PR, when we first started working with CSC back in 2004, Trek’s team Liasion Scott Daubert told me ‘Remember, no matter what happens to make something break, it is always seen as the manufacturers fault.’ So I joke with Scott Daubert at Trek, it wasn’t quite as bad as Hincapie’s steerer tube, but it sure felt about as bad when it happened. But that is a lot of what drove a lot of the initial discussions into what became Cervelo Test Team."

Poertner’s point is that they needed a team over which they had complete control. They had tested the 303 to be cobble proof with 27mm tires, going so far as casting actual cobbles to create a bump drum for testing.

"We literally had thousands of engineering hours in trying to build cobble proof wheels. The problem with cobble proof wheels is, in a week we could build a rim that could survive the cobbles, but with carbon, the stiffness of the material is so high that as you add strength you’re inevitably adding stiffness. Our rim shapes are tuneable, the toroidal shape gives you a leaf spring effect, we can add damping materials to damp vibration, we can control to some extent the sidewall spring rate, but the reality is that at some point the wheel just gets so stiff that the guys don’t want to ride them, particularly as the bikes are already so overbuilt for that race so that none of those component manufacturers risk failure either.

That whole process led to the carbon bridge technology, which is that Kevlar sewn rim edge, which has led to huge perimeter efficiencies in term of strength and stiffness per weight within that very localized region. But it didn’t affect the whole rim, so we raised the impact strength 30+%, but the stiffness of the rim only went up a couple percent."

However, the day of the race turned out to be dry, so Backstedt decided to run 24mm tires at 72 psi (5 bar), an untested combination for his 210 lb weight. Zipp later replicated those conditions at the lab and cracked the rims each time.

"I was on the phone with him a few days after it happened, and he said in the six times he’d done Roubaix, he broke or cracked wheels in five of them. The one time he didn’t was the time he won, and he said afterwards those wheels were bent with hairline cracks at almost every nipple hole. The upside of aluminum is that it will bend long before it cracks, and you can keep riding a bent wheel. He told me then that we’d probably never see carbon at Roubaix again.

So it’s that fine line of ‘the ideal race car is the one that falls apart inches after the finish line’. That’s the hole we’re in, but to this day I’m confident that if he’d run 27’s that day as he had in our testing we wouldn’t have an issue."

The flip side of that story, which went largely unreported, was that Martin Maaskant rode a stock set of 202’s with with 24mm tires that day and finished 4th, the first ever finish at Roubaix for a carbon wheel.

"It was tearing us up, first ever finish, fourth place, on a bone stock nothing special 202…a CLIMBING wheel of all things. Of course, he’s a 155 pound guy, so on 24 mm tires at that pressure it’s a totally different dynamic. For me, it was made that much more painful by the way the press hung the failure on Zipp, exactly as Daubert had predicted. The reality however, was that Backstedt and Hincapie, were wheel to wheel in the Arenberg forest and both broke their wheels within feet of each other. Hincapie shattered a pair of Hed’s and we never saw a word about it anywhere in the media. And this year, coming back, Hincapie, on Columbia, (sponsored by Hed but running mostly Zipp), rode a very traditional aluminum setup."

Finally, this year in Roubaix Zipp had 16 sets of 303’s, and not one single issue. Hushovd reported that he had the most perfect wheel setup he’d ever experienced at that race.

Pro Riders and Wheel Choice

We talked about several instances where pro riders chose wheels out of feel, intuition, or superstition instead of science, starting with Kristin Armstrong at the Olympic TT, where she rode a flat disk instead of a Sub 9. Poertner calculated that the heavier Sub 9 would’ve cost Armstrong a second or two uphill, but would’ve gained 5 or 6 downhill.

"And the thing she came back with, really struck me, she said, ‘the downhill is so technical I feel so speed limited by grip and bike handling, so any aero benefit I’m going to pick up on the downhill with that wheel, is going to be negated by the brakes regardless.’

So that’s one of those situations where we can run the computer model, but it can’t decide how much to brake coming into the corner. The other piece of that that’s hard to ferret out is rider confidence. Having ridden both disks a ton, I feel like I can corner faster on a Sub 9 than a 900, because of the suppleness. The rim bulge acts like a leaf spring and makes it ride more like a spoked wheel."

We also spoke about Cancellara and the Sub 9. He initially rode the Sub 9 on a Cervelo P3, and with the tight fit at the chainstays, he was able to make the wheel rub. Though chainstay rub is due to frame, not wheel, flex, Cancellara came to believe the Sub 9 was too flexy. It wasn’t until he switched to the Specialized Shiv, with its wider chainstay clearance, that he began to appreciate the Sub 9.

"He’d done some testing on it, and we were on a conference call, ‘It’s amazing, it corners like a spoked wheel, it’s so comfortable!’ He just loves that thing."

Cancellara went on to win the Tour Prologue on the Sub9 and finish second in Annecy on the same setup at this year’s Tour.

Another example is Carlos Sastre, who rode 202’s almost every day at the ’08 Tour, despite computer models that indicated that he could’ve hit the base of Alpe d’Huez with 250 calories in reserve if he rode 303’s.

"For a rider like him, the last couple of his big victories have been on 202’s, so there’s this internal confidence in that particular wheelset that’s so high, that I’m not going to take it away from him. At some point, there’s a mental benefit that’s as great as the performance benefit between these two subtly different products. It’s not like we’re having them pick 303’s over aluminum training wheels. It’s much more nuanced than that. I mean, 808’s are heavy compared to 202’s but they’re still really light compared to almost everything on the market. The 808 tubular weighs the same as a Campy Bora, but if you talk to the Campy teams, they look at that as the Bora as a climbing wheel, ’cause that’s what they’ve got.

Our teams are a little bit spoiled. They’ve got the full range of five depths, multiple disks, they have the whole thing at their disposal, and they have all the data to make it meaningful. It can certainly lead to paralysis by analysis, but for the riders who are interested and are technical, it’s a huge benefit for them."

Cancellara and 808’s

"One of my all time favorite stories of dealing with the teams, two years ago, going to the Tour, I arrived at the team hotel in a little town the day Fabian won the Tour stage into Compiegne with that 1k solo. I’d been on the road all day, didn’t even realize what happened, and there was a big celebration. And Fabian got up, gave me a big hug, and he said, ‘808 is the new 404 for me!’. So excited.

We’d been in the wind tunnel just a couple months earlier, he agreed to be the guinea pig, and we’d never had an athlete do this, he agreed to just sit on the bike and let us put every different wheel under him. But it showed him the drag difference, and calculating that back into watts, and we showed him. We put a pair of 3 spokes under him, and he saw that they’re essentially a little slower than 404’s, but his 808’s had them by 20 grams or so. Jens Voigt had been riding the 808’s quite a bit at that time and was quite a believer, so the guys were interested, but they just hadn’t made the leap yet. One of the things he said, which kinda struck me to this day, ‘I just felt like when I went, I knew I was riding a TT bike compared to what these other guys were on.’

He’s right. You look at the numbers, that Cervelo he was on, with those wheels, compared to what the other guys were riding at that speed, WAS a big advantage. Of course, on top of that you have power and tactics, all that stuff comes into play, but for all of us, that was a huge insight into the emotional, psychological advantage of, ‘Wow, I don’t just feel fast today, I have the greatest tools I can have. If those guys are going to catch me they’re going to have to make significantly more watts.’ That, in and of itself, is an advantage."

Wheelbuilding and QC

I had a 404 front wheel built to 60kg of spoke tension, and an 808 front at 110kg. I asked Poertner why there could be such an inconsistency.

"We don’t have that many builders, six wheelbuilders? All by hand, and every builder’s responsible for quality control, spoke tension measured every wheel, 100%. There are protocols and procedures, but mistakes can certainly be made as with anything, but on average our wheelbuilders have each built thousands of wheels. I’d say our quality tends to be at the top of our industry. But things definitely happen once in a while that are not of our ideal. Our goal is to eliminate as many opportunities for mistakes to be made and to put systems in place that produce the highest quality product with great consistency. Every year we talk with hundreds of dealers and they reports that our quality and consistency are at the top of the industry, but of course, mistakes can still be made.

We’re actually stepping it up to the next level, going to a digital database (SPC) using a digital reader on the spoke tensionometer, so it can kick out a meaningful number into the database. Every wheel will have a huge list of data linked to its serial number. The goal is to be able to pull up a serial number and see exactly every spoke tension when it left the factory. See the trueness, see the roundness, have it digitized. It’s exciting and a ridiculous pain in the ass. You can imagine what that costs…but we feel it important."

Durability, Cost

Finally, we addressed what I consider a major bugaboo with carbon wheels: durability. I’ve cracked 4 Zipps this year, 2 due to operator error (sprinting straight into a pothole in a race started in total darkness), and 2 while supposedly JRA (just riding along).

Poertner described a process that every Zipp sales and customer service employee goes through. A steel bar is laid down in the parking lot, and everyone has to ride over it and break a wheel. What they find is that the pass that doesn’t break the wheel hurts more than the one that does, since energy is absorbed as the rim cracks. So if you think you broke a rim while just riding along, it’s probably because the rim sucked up the impact and lowered the perceived impact.

He also discussed how Zipp’s long history in carbon can work against them – if you make wheels long enough, eventually everyone will know someone with a broken Zipp story, or heard it on an internet forum. Finally, he addressed the cost/durability issue:

"Design and engineering, everything you do has some tradeoff somewhere. The product we put out now really shows that we try to take as much tradeoff out of the product as possible, and the place where we do have to give it up is the cost. You just have to suck it up. Take carbon bridge. We’ve invested a fortune in this technology, both in terms of developing the concept and testing prototypes (more than 300 wheels tested to failure in the lab), developing the technology and equipment to produce the rim, researching the vendors, and it’s expensive. It adds quite a lot of cost to every rim, but the weight penalty’s only 6 grams per rim, the strength went up dramatically, the stiffness is improved, so our only tradeoff is cost. And we think our customer is willing to pay for that cost. It’s one thing to show up to the market and tell it, ‘You’re going to pay an extra $100 because we want you to, but we show up to the market and we say, ‘We did all this stuff to make this product better, stronger, stiffer, and we didn’t add any weight to it. But to do that we had to develop all this technology, and the cost of that technology has raised the wheelset $100.’

To me, a wise and interested market responds positively to that, and they did to carbon bridge. It’s been one of the most successful technologies we’ve released. We see it here, crash replacements, impact damage to rims, is just, I won’t say non-existent, but it’s very, very low. We’ve seen almost no failures from the pro teams this years with Carbon Bridge and I’ve heard numerous times this year from dealers that they are seeing less crash replacement with us than our competitors, even though they are selling more of our products. But of course when you have 21 years of product on the market, and you are the company that invented the carbon rim, it’s going to take a long time for anecdotes about rim durability to change. As of today, the data and testing show us that nobody is making a more impact resistant or durable rim, and certainly nobody is even close when you factor in aero performance and weight."



what’s a leaf spring? i could google it, but since he uses it twice i feel like i should know what it is already

Noah Tarmac

Whatever happened to the days of debating 28 vs. 32 spokes? Tied and soldered, or not? Or guys showing up on exotic 24 spoke front track rims and getting crap for it? Or getting all geeky on different spoke lacing patterns?

The Zipp guy is impressive and they really seem to care about the product but I just don’t see how $2500 wheels help anybody except a Cancellera.

My old school, handbuilt 32 hole wheels work plenty fine for training, racing etc. Just asking. Now please debate. I want to be convinced of the need to upgrade.


Noah, if you spent more time being a good consumer you wouldn’t have to trouble yourself with such introspection.

We are all Noah

Nah, never tried them so I speak from a point of high ignorance. I’ve seen them in shop windows and suspended between carbon fibre tubes on exotic bikes, seductively winking at me, saying come on, give me try, ride me. But then I said fuck it and got on my bike and went for ride. Usually works out ok. Maybe someday I’ll cheat on the old warhorses and have a date with the little woven vixens but for now I’m happy to ride the old girls.

I’m not anti-expensive stuff that makes amateur riders marginally faster or more comfortable just skeptical about the ‘need’ for it. If guys say ‘I like it because it looks all bling and makes me feel/look fast/pro’ that is totally honest answer and just fine by me. But saying I like it because when I’m sitting in the back of the pack doing no work for 90% of a race and then jump to the front and the magic powers of a deep dish rim suddenly allow me to accelerate away from my weak legged companions is total crap.

Guillaume Pulley

there are plenty of much cheaper deep carbon wheels which are 95% as good for much less money. if they save 10 watts at speed over a decent aluminum wheel and cost the same and look good too, why not?

Gaetan Hammer

Ebay – Matrix Carbon Tubulars = $600.

Neuvation = $750
Williams and Revex = $1000

Zipps are $2500 and if you race them you will crack them.


mavic makes cheaper stronger aero wheels for road racing.
zipp makes more expensive weaker aero wheels for TT and TRI.
both shops make money, cyclicsts think they are faster and look more pro equipped with either one, so who cares. life is good….

Sandbagger Vance

The benefits of aerodynamics are so dramatic that I can ave 2-3 mph faster around central park on my TT bike than I can I my road bike. And I consider it unfair advantage over the cannibals.


I still don’t see how he disproved the contention that the Revolution wheels are 90-95% of the performance for less than half of the price. Just because they put a shit ton of resources into R&D doesn’t mean that it is worth the price premium for the marginal improvement.

Gabin Torque

I want to know how much does a Zipp rim flex? The reason I ask is that they are concerned with making a rim that is too stiff. I always thought that since a tire flexes so much compared to a rim, that the rim flex is not noticeable. Not to mention the spokes that also flex a bit. There are so many variables that I want to know how they attribute it to the rim and not the other components.

Frames flex and wheels flex too. So when a rider got wheel rub, how can they attribute the flex to the frame and not the wheel? Then they say that when the rider went to a wider frame there was no rub.

You asked “I had a 404 front wheel built to 60kg of spoke tension, and an 808 front at 110kg. I asked Poertner why there could be such an inconsistency.” . He didn’t say whether those numbers were right or wrong for the wheel. Was one of the wheels built incorrectly? Or were both built correctly?

Gabin Torque

Most of the aero advantage that gets you 2-3 mph faster on your TT bike as compared to your road bike is due to your position on the TT bike, not the wheels. The wheels help, but the improvement is smaller than good position on the bike. Good position and an aero helmet are where you get the most bang for your buck spent.


The 404 at 60kg was built wrong. It should’ve been in the 110 range.

The long answer to the wheel rub question (edited out) is that if a wheel flexes, it should rub at the seatstays, not the chainstays. The contention is that force applied at the contact patch, twisted about the dropouts, shouldn’t make the wheel flex at the chainstays. So if there’s chainstay rub, it’s probably the frame that’s flexing. The Shiv has more clearance than the P3, so there was no wheel rub.

Gabin Torque

revolution wheels probably have 90% of the performance of a zipp, but if zipp didn’t spend the money on R&D, revolution wouldn’t have a wheel to copy. So the only reason revolution can offer the wheel they do is because they copy zipps. Performance doesn’t come cheap, unless you steal it from others.

We are all Noah

Thanks for that. I’ll show up on a TT bike for my next mass start race in Central Park. I’ll average 2 – 3 mph faster than everybody else. I will win! But wait, if we all show up on deep dish, carbon wheels who will win? Doh, the guy with the disks?

Dude, who cares that when you are alone at night measuring watts and mph in the park on a bike (that lets face it, just looks wrong) trying to figure out the aero impact of having a gel shoved up the front leg of your shorts, you’re faster.

I’ll admit I hate TT’s and when required (stage race) to do one I race to make the time cut on my road bike, in the drops, cannibal style. The heavy geekdom and investment required to be a mediocre amateur TT’er is waaaay too much for my brain to take in so I just leave it for triathletes and TTVegan.

I’m thinking of the epic 13 minute Empire led laps earlier in the season. We were doing something like 30 frickin’ miles an hour, no amount of carbon was making anybody there faster.

The only point I’m trying to make, and damn I’m coming off like a total retro-grouch here, is that while Zipp makes a damn fine product and there are lots of other interesting options if you’re into expensive wheels they aren’t necessary to perform well at all but the loftiest heights of our sport. Expensive go-fast may make you feel good but legs do the loudest talking.

I will now begin my off-season regime of jogging in a heavy grey track suit, Rocky-style, jumping rope and doing squat thrusts with inanimate objects I find on the street – typically homeless people.

We are all Noah

No! My opinion is worthless. I freely admit that. My observations on the futility of it all, however, are priceless.

I bid you adieu Sandbagger Vance. You are but a spec in the distance, motoring away 2 – 3 mph faster than I, in this time trial we call life.

Ethan Brakepad

I wish I had Zipps or any carbon rims, but Im one of the guys who rarely goes off the front and doesnt have the legs to make it worth while in my view.

I have been riding Xyriums for years now, and have yet to have even a single problem with any of the 3 sets I own. They are light, great for races with any climbs, and run smooth as you like. I train, race, and rest with the Mavics, and my $800 investment per set is still being amortized every month to some very low number by now. Untold thousands of miles per set.

When I see guys in CRCA cracking and breaking Zipps in CP just to look cool in our club races, I just shrug and wonder what that does to the cycling budget for the year for the rider. Maybe they are stinking rich. Who knows. Good for them, but Im spending less and doing just fine in races thank you very much.

Would I benefit from carbon rims? Yeah, a bit. And feel fast too. And my fragile mental state might feel soothed for the extra mile. Is it worth an extra $1,500 per set times the extra sets once they break? Ahhhhh, nope. Not to me.

Have fun “playing Fabian” out there, and enjoy that extra work day or week or two or month or whatever it takes to pay off the wheels. If I were Ken H or strong Empire rider, Id prob buy them too, but sadly, Im just the “better than avg” NYC racer and it isnt gonna help me till I go elite, which I have no plans to do. Ever. Sigh.


FWIW (perhaps not much), Reynolds makes excellent wheels and offers an extra 3 year warranty that costs about $250. They are supposed to be durable anyways, but if they break for any reason, you send them in, they fix them, and you get working wheels. If you’re going for this level of investment and do any kind of varied racing, this is the only way I think it makes sense to purchase deep dish wheels. It’s only a matter of time before they crack.


Samuel Chamois

This is what annoys me about Zipp. Poertner obviously has a lot of passion about his work and Zipp makes great wheels, but he still couldn’t give a lot of straight answers, except maybe about the Hed stuff. If their engineers read the marketing copy, its a marketing driven company.

Also, an 808 clincher is listed at 1891g, not 1680. Bora’s is listed at 1305 grams and 808’s at 1462g, hardly “weighs the same as a Campy Bora”. If Poertner can’t get his weights right, why should I trust his aerodynamic claims?


I heard that Ken Harris hand crafted a perfect set of aero wheels only to find next year Zipp copied his wheels and stole his design, with 90-95% of the performance.

Gabin Torque

Smart enough to design a great wheel and also to repeat only the positive aspects of his wheels. That is why they allow him to be interviewed without handlers.

Guillaume Pulley

cosmic carbones are bombproof. tons of people race them at floyd, I’ve never seen one break.

had a pair of spinergys, beat the living crap out of them, had to rebuild a hub but they never broke.

neither is a light wheel, but that means nothing around here.


should be buying Hed Jets or Cosmic Carbones with alloy rims and carbon fairings which hold up as well as any regular alloy rim.


what up with 12 spoke Rolfs

if you look at data all the best wheels are 16 or fewer spokes. less spokes adds up to way more than a deep section wheel in watt savings

Jasper Sealant

Rent when it counts. Pay the $150 for the day and get insurance or whatever. It is like Zip Car but for wheels.

Why anyone would want to assume the risk of a $2K set of wheels is beyond me. Unless you’re loaded which makes it your problem.

Since you’re probably going to get 20 odd races out of your 2K set of wheels before they poop the bed, then you might as well rent.

Paul Rubber Hood

Don’t rent from Echappe. Their website sucks and will let you order (and pay) for wheels that they don’t have available for a given race. Then they tell you that they won’t give you a refund because they don’t give refunds to anyone (just merchandise credit).

Tom Ergopower

id take Fabians leg power and a set of rusty 50 spoke 1970s wheels on a broken down Schwinn. Beat your asses any day in the park. Better bragging rights and a hell of a lower sunk cost.

I ain't no Noah

So what does he know about carbon race wheels? Anyhoo, speaking from my own personal experience, I have had a set of 606 clincher wheels for a while. In fact I’d say they are about 3 years old and have over 6k miles on them. I race and occassionally train on them in the summer. From my first hand use I can say the follow:

>They are very fast, with a marked improvement in speed over all of my other wheels, including; Mavic R-SYS (total dogs, and recalled by Mavic) Mavic Cosmic Carbone SL Clinchers (a nice bomb-proof alternative), Mavic Ksyrium SL, American Classic 450 (a bit flexy), Rolf Prima Elan (my favorite climbing wheel) and Mavic Ksyrium Equipe.

>They are relatively durable, I have wacked a few potholes and still they hold up. I have also crashed while racing on them with no need for truing. Call me lucky!

>They are not the lightest, but still lighter than most of the other deep section wheels on the market.

>They are stiff, quite stiff laterally and yet are somehow very comfortable. I don’t know how they do it, must be carbon’s natural tendency to mute road buzz.

>Zipp’s innovative engineering and quality of manufacture is some of the best I have seen. (Although, the front hub from 2006 has a bit of play, this appareantly was by design. In any case it has been changed with new hubset for 2009.)

In a nutshell, from my 20+ years experience riding and wrenching on bikes I can honestly say Zipps have come a long way since their Ti-spoked cracking wonders wheels of yesteryear. They are now some of the best wheels on the market. Are they expensive? Uh yeah! However, in my opinion you get what you pay for. Well, that’s my .02 cents worth. I’m sure I’ll get flamed by some of you dyed in the wool 32 spoke types out there. But, as the saying goes, there’s no stopping progress.

Ivan Bentspoke

The problem with wheel (or any other component) evaluation is that subjective feel doesn’t necessarily correlate with objective results. I’m sure the 606 feel faster and probably are faster than cosmic carbones, but the differences are very small (and carbones cost half as much). People freak out about the perceived difficulty of accelerating with heavy rims but I’ve found that I reach pretty much the exact same speed sprinting from a standing start with every kind of rim even though the heavy rims do in fact feel sluggish (though usually stiffer) and my hill climb times are pretty much unaffected by switching back and forth between wheels with ~200-300 gram weight differences.

The bigger issue is that cycling is already an expensive sport, which isn’t necessarily a problem for people with money to burn. But I think it’s important to emphasize that while high end equipment does indeed yield marginal returns, there is no need for amateurs to blow massive amounts of money on it. I’m glad that Zipp exists and well serves a very particular market, but the perception that you need that type of equipment to do well is bullshit and I think there should be far less emphasis on expensive stuff in the sport. I like that while Andy can afford all the latest stuff, he has still given a fair shake to budget options like the iBike for power and the Rev wheels.

Guillaume Pulley

even the budget stuff is pretty expensive, when you think about it. $900 for a set of revolution wheels is “cheap”?

with a little bit of research one should be able to find a perfectly serviceable (used) race bike for that…one that will not lose you a single place in any race when properly set up.

most racers like gear for it’s own sake, and there is something to be said for the idea that if you spend hours and hours on a bike you should really like it, but the amount of money people spend on gear (who often don’t really have it to spend) is a little nuts

Jordan Hammer

Maybe next he could engineer a functional voice mail system at Zipp. If you’ve ever had the pleasure of calling them, they’ve got the most convoluted set up in the history of the telephone.


Would it not make sense to limit the use of these high end high price gizmos to the “high end” of the peloton? The price of a carbon fibre frame is SOOOO high when these hoops are added, it seems like an insane entry level cost. Get some ambrosio hoops and sewups and go fast cheap like we did a long damn time ago. And spend the winter patching and sewing when you can’t stand one more f**king minute on the trainer. I sincerely doubt anyone below Cat 2 would benefit from them anyway (except in their muddled head).


Noah…U just don’t get it dude…The idea is to spend so much money that by osmosis U become fast. This is the obverse of spending so much time on the bike that U become strong.
What U have to believe is that spending HUGE amounts of cash will make U as strong and fast as Mr. Cancellara.I WANT you to believe this! I WANT you to believe that a $3000 set of wheels will make U so fast as to be unbeatable. Once I’ve got U convinced of that (and knowing U have considerable resources) I’ve got a bridge I’d like to show U.
Get some good box rims and sewups.
As the saying goes…
Don’t do upgrades, ride up grades

Quinten Brazeon

$350 gets you a pair of Xero XR-1’s, a 30-mm V-section alloy rim with standard spokes, weighing in at 1580g’s, and pretty smooth hubs, I and I smoke most all yahz on dee rode noah.


little in the way of any aero benefits and it appears aero beats weight in all but the hilliest of courses.

West Coast Reader

From the pictures people are not riding steel frames nor Performance branded frames either so either most of the posters never do race or they say one thing and do the opposite?

Try a freaking pair of deep carbon rims and then re-post what you think.

Its not about how much money you have nor how bling nor how techie you are or if you like to ride square wheels. Its an article about a Zipp Engineer and his craft. Try it out, what do you have to lose? Don’t you like to ride bikes?


That is all this boils down to. Do you need carbon bars, Campy Record, etc? No. a full aluminum bike with midrange or evenlow range (SRAM Rival, 105 etc) will work just fine and actually hold up better for a fraction of the cost and a minor weight savings. Most guys here racing PP, and CP where weight and Aero means little as most races come down to a sprint. We buys this shit because we want to and we enjoy blinging out our bikes.

Nothing wrong with this. We love bikes and all the cool stuff that goes with it. As for Zipps, you are paying for marketing and R&D. You can find wheels on ebay or direct sales (williams et al) for less and with 95% the performance. But like someone already said, these companies have benefited from Zipp, Hed and Mavics R&D.

Luchino Nipple

Andy – any discussion re: nipple hole cracking vis a vis internal/external nipples (e.g. EDGE v Zipp)? My question stems from CX where aero is less of a focus, but strength is and the nipple holes in EDGE are super strong.

Second, did you discuss why Zipp prefers to use NDS loading instead of DS loading? Does the NDS load and/or radial DS lacing really provide such a benefit?

Clammy Chamois

As a good friend w/ a $5,000 (8 yrs ago) Serotta set-up once stated, “I’ll spare no expense in looking fast”. This after I had just thoroughly kicked his ass on my $1,500 ghetto set-up.

West Coast Reader

Isn’t $1,500 over doing it if you’re that good, couldn’t you of saved at least $700 by getting a bike at Performance?

What a show off.

Florian Supple

nowhere is an expensive bike going to show less of a result than in a man on man “ass kicking session” where one person is obviously fitter than the other. who cares about your little story, it’s irrelevant.


I once won a State Line Sprint and Gimbels intermediate sprint in the same month!
Bikini Bottom Special!

West Coast Reader

The guy who won remembers the other bike not his own, nor lists it. LOL, too ashamed of his bike to list it, probably worth ~$500, the $1,500 was to save face LOL!


Your “Zipp vs Asia” especially your mentions of Gigantex in that context would be considered libel if the manufacturers here cared enough.

In fact, Gigantex is also an OEM manufacturer for Zipp’s parent company…

That “Zipp vs Asia” section is so woefuly misguided it is comical.

Zipp is also not a pinnacle for quality. The rims do crack around the spoke holes, and the hubs are awful. Once the rims crack and the hubs fail, they also refuse to honour the warranty to the great frustration of the shops and distributors.


The implication that the only R & D done in Asia is just reverse engineering and that Zipp invented the wheel, carbon fiber and have all the answers, which was topped off by this:

I asked Poertner that if this was so, why would someone buy a Zipp instead of knockoff.


Your refers to Andy, not Poertner. Poertner’s claims are just mildly comical and are a great example of “group think” or thorough “handling the media” briefings.

Jonas Topcap

Zipp used to make pretty lousy hubs, just like most other boutique wheel builders. Everyone has gotten better, so it is expected that Zipp has also gotten better. If you want a good hub you can’t do much better than Shimano and Campy. Best bet is to buy a Shimano or Campy hub and then build that up with a Zipp rim. You can then make sure you build up the wheel right, not like the bum build Andy got.

Ken Harris

The wattage forum left topica a few years ago, and is now hosted at google.

What bothers me about any manufacturer is when they clearly know about problems with their product but downplay, deny, or fail to disclose these problems, especially when you trust your life to said product maintaining it’s structural integrity.

Wheel design is always a compromise, wheel choice an optimized compromise for anticipated conditions, but lack of honesty about the product verges on contempt for the customer.

Keano Headset

If new hires can break wheels just like that (i.e. with no foreknowledge of how they might fail), It makes me never want to buy anything from Zipp.


The way it was described in the full interview, it takes everyone a few passes before they build up enough speed to break the wheel. I can’t vouch for that, just repeating what Poertner said.

Quentin Rubber Hood

The Zipp engineer Deeter helped me to get to bed 25 minutes earlier than my PR (personal record not Puerto Rican) time.

My normal level of “growing tired of it all” rate was increased when he slammed Steve Hed. My measured “Inertia of sleep” was compounded by his dissing Kristin Armstrong on her wheel choice decision as “just intuition” while his science showed otherwise.

over all Zipp truly delivers again on who they are perceived to be.


Some funny comments here, I have to agree. But the bottom line is that Zipps are great wheels.

The 404’s are simply fast and light, and I’ve owned some for years. I have a Zipp disc too, and folks have too keep in mind what great improvements in weight Zipp’s made on discs a few years ago.

Yep, I’ve cracked Zipp rims and incurred the expense of replacement. But it was a fast turn-around and fair enough price (but I sure wish it was less).

I’ve never ridden the newest Hed’s or any of the other high end deep dish wheels, but I’m sure they’re great too. For the most part, you get what you pay for.

Maxime Bearing

I owned a pair of Zipp 217 hubs from 1996 to 2004. I had them on a Spectrum bike. I had nothing but trouble with the rear hub which went back to the factory twice for rebuild. I swore off Zipp and got Bontrager with better results.

Logan Clearcoat

I’m surprised people actually found this boring. I personally have no interest in actually spending more than a few hundred dollars on wheels, but I still find all the thought, research, and testing that goes into high-end products to be absolutely fascinating.

Sure, the guy is totally biased towards his company, and maybe he exaggerates a little here and there. I’m just glad so much of the interview was published instead of one or two crappy quotes along the lines of, “carbon bridge… leaf spring… ZIPP wheels are the best.”

Arnaud Chainline

Truly amazing this company still believes its own garbage.A quick search on youtube will show tons of riders with collapsed carbon rims. The wheels are so light yes but flex like crazy and to the extent where the tyre will touch the chainstays and rims hit the pads on both front and rear


They flex so much because you’re a fatty and shouldn’t be riding them due to your largesse. Ease up on the Kripsy Kreme’s there, chub-o-rama.

Mr Breakaway

Going for a breakaway in my next big race, so changing out my usual Mavic Cosmic Ultimates for a friend’s 808’s. Have ridden them before and definitely notice a difference over 40km’hr. When you get up to 50+ it is unbelievable. I normally enjoy the Mavics as they are light and very stiff, I accept the Zipps flex more and there will likely be some rub on the brakes when out of the saddle riding hard, but the aerodynamic benefits for what I want to do are massive. I ride professionally.


Josh is teaming with knowledge and an intense passion. Despite all of the comments, Zipps are still popular and if they were breaking more than competitor wheels and were priced higher, why would racers still buy them. The wheels are high priced and not in reach for a most cyclists, compared with Mavic or DT Swiss, they don’t offer a range from entry level to high level rather stick to the high-end.

I recently spoke to Josh on this and help helps put things in perspective, you can’t blame him for being pro-zipp but as cyclists we have to be realistic about the performance value we can expect.

Tony Martin, at the worlds, rides thousand dollar ceramic bearings. For the consumer, you can buy a better tyre and you’ll save twice that. You put latex tubes in there you’ll save 6 times that amount. A new chain on your bike can be as much as 6 watts compared to a worn chain. Just cleaning your drive chain is a couple of watts. 1 watt of ceramic bearings is about 3 seconds per 40 kilometres.

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