Discs can be a bit of an enigma to first-time triathletes. Here you are racking your road bike in transition, thinking about how ready you are. You probably installed aerobars and a BTA, or maybe you’re still stock. Either way, when the guy two spots down shows up with a disc on the rear, you just stop and stare. A little while later as you’re deep in Zone 4 out of T1 with your heart pounding, you hear a distinctive “whoosh, whoosh” out of nowhere. What the heck is that noise? For a split second you wonder if you flatted, but then you see it—your transition neighbor goes blowing by you on that disc.
We’ve all been there. And we’ve all wondered (and possibly assumed) that it must take some huge degree of talent to ride something like that. But like so many assumptions, they are not based on fact, but on rumor. And we just spent the past four months putting that rumor to bed.
When we were talking to Zipp about a 404/808 review last year, they offered us a challenge. Instead, would we be interested in spending time with what they consider their fastest triathlon option – an 808/Super-9 setup – as our everyday wheel setup. Now this isn’t the first time the team is riding a disc. We’ve also completed a couple of disc cover reviews here and here, but none of us have ever made a disc our daily setup. Not that Zipp needed much help selling us on the idea, but they had Zipp athlete Mackenzie Madison talk us through her race day wheel decision. While we may be paraphrasing here a bit, the short story is that, as long as it is allowed, her rear wheel is always a disc. Then the big question becomes 404 or 808 up front?
Needless to say, challenge accepted! But before we talk about the Super-9, let’s jump into the biggest reasons why we knew this was a challenge worth taking on.
Riding a Disc
First, let’s get this out of the way – riding a disc is nowhere near as scary as you may have been led to believe. By the way, let’s be clear that we’re talking about riding a rear disc here. Riding a front disc is a whole different animal, and one we would never recommend unless you are on the track. While you intuitively look at the disc and see what would be a potential sail in the cross winds, the fact is that riding a disc in cross winds is more than manageable. Although there does come a point where you simply wouldn’t want to ride a disc, which is why even the pros don’t ride them in Kona. But let us get to that later.
Believe it or not, when riding a disc, it’s your front wheel choice that has the most direct effect on how the wind impacts your ride. This is due to the front wheel’s placement under the steering axis. The deeper rear acts as a corrective force on the shallower front, due to the fact that it is further from the steerer tube and that it is the non-control side of the lever system. The result is that it will actually push the bike back in the direction of the crosswind, acting as a counter to the shallower front, which has a lesser force total. As we mentioned earlier, there is a point at which the rear in a cross wind does act as a sail to the bike and can physically move the rear outward, negating the counter steer it provides, and simply picking up the entire bike (this is what we call having a really bad day and why Kona outlaws discs.)
To further clarify, a disc will only move as much as the bike does, and this is why Mackenzie was making her front 404 vs 808 decision. On windy days she was going to go with the 404. On calmer days she went deeper with the 808. Either way, in almost all circumstances, she chooses to go with a disc at the rear.
Weight also tends to be another big concern with discs. It’s often assumed that the slightest climb will quickly become Alp de Huez while riding a disc. But let’s break down that difference. Zipp claims a weight of 1000g for their 808 rear wheel and 1175g for the Super9. So yes, there is a weight difference of roughly 175g. This is noticeable but certainly not unmanageable (even over half-iron and full-iron distances). Now that being said, we are in no way saying that no race or ride will ever be affected by riding a disc. If you are going to spend most of day out of the saddle climbing, we’d probably go with the non-disc option. Of course if that’s the case, we would probably be going shallower than an 808 as well.
The Zipp Super-9
So now that we know that riding a disc isn’t going to be the scary roller coaster we’d envisioned, let’s jump back to the Super-9. Zipp states that the Super-9 Carbon Clincher disc is THE fastest wheel ever. And while we cannot validate that claim, we will accept that it’s Zipp’s fastest wheel ever, and that still says a lot. Zipp has been the 1,000 pound gorilla in the wheel market since it was first launched in 1988. (if you want a long stroll down memory lane, here is Zipp’s first catalog from 1988 with the Zipp Disc) And while they aren’t the only big name in the sport today, they are certainly one of the biggest players out there. At Kona 2014 Zipp had 1,839 wheels under athletes. While the next highest wheel company only had 266! (Lavamagazine.com)
The Super-9 Carbon Clincher features a max width of 27.5mm with a brake track width of 26.46mm. This non-parallel brake track helps to smooth the airflow transition from the tire to the disc’s surface, which provides one of the major aerodynamic advantages of the wheel. The Super-9 also features Zipp’s Aerodynamic Boundary Layer Control (ABLC), more commonly known as the “golf ball pattern” (in this case, the dimples are found in 5 different sizes), found on almost all Zipp products. ABLC works to create a slight turbulence directly above the rim surface, resulting in a lower level of integrated drag.
The Super-9 ships with Tangente Platinum Pro Evo Brake Pads matched with Zipp’s carbon braking surface. The pads themselves feature an enlarged surface area and improved clearance to work with integrated brakes.
Oh, and we forgot what we consider to be one of the best features of this disc – it’s a carbon clincher. We here at AG are huge fans of clinchers. There is something freeing about leaving for a long ride with only a spare tube and tire and still knowing you should have no issues getting home. And on race day we simply double up by packing two tubes in our repair kit and a tire under the seat while still feeling confident we will get to the finish line. After all, we have all seen what happens when you flat on course and have a bit too much glue on the wheel.
But in all honesty, we don’t think convenience was the biggest reason Zipp made the move over to carbon clinchers. In one word it was all about SPEED. With carbon clincher wheels, manufacturers can create ultra-thin tires with an extremely low rolling resistance combined with shapes that are built to match the wheel design, all for one continuous aerodynamic shape. By the way, this is why we see so many wheel manufacturers now getting into the tire game as well. Zipp’s athletes have taken to this belief in a big way. We have seen Phinney, Carfrae, Martin, and Vanhoenacker all riding clinchers these past few years. Tom Anhalt of Blather ‘bout Bikes recently did a rolling resistance test of Zipp’s new line of tubular and clincher tires versus their older tires. The results are really quite impressive and show you what clinchers can do.
True to our word, we rode the disc a lot. Of course this is contrary to our usual habit of training on “slower” equipment and racing on fast. We strive to find an ideal balance, which typically means we ride once a week with race equipment in the two months leading up to a race. However, the end result of riding the Super-9 so much was that even when the weather reports were mentioning 19mph cross winds on race day, we had the confidence to never once consider pulling the Super-9 off our race frame.
So how was the Super-9 in the wind? Exactly as we expected. We never felt it when being hit by a continuous wind, regardless of direction or intensity. The few times we took notice was when we were hit by a wind gust—whether from wind force alone, or as a result of wind tunneling between buildings and overpasses. In those cases, you felt the impact throughout the frame and not just at the back. As we mentioned earlier, the disc is only going to move as much as the bike does. And even in those instances, your body corrected for it instantaneously and you were on your way. Over a 56 mile compass point course where we felt the wind from every possible angle, we never once regretted our choice of disc. In fact, we were thankful for all of the training rides that helped build our confidence to ride it regardless of the predicted crosswinds.
From a ride characteristics perspective, the Super-9 is a blast. It’s stiff but completely comfortable. We soaked up the miles, never wanting for a different wheel during long training rides. Braking performance was exactly what we have come to expect from Zipp – strong and reliable. We never took it on significant descents, so we can’t speak to how it handles heat buildup. However, we can say that the braking abilities of the Super-9 never let us down.
Oh, and in case you didn’t catch that earlier, this is a clincher. And who doesn’t love an easier tire change? Zipp has actually spent quite a bit of time improving the speed at which a tire can be swapped on their clinchers, and it shows. This was honestly one of the easiest tires we have ever put on, and we greatly appreciated that. Zipp ships the Super-9 with an inflation adapter (better known as a “crack pipe”). Although we actually stuck with our Silca Hiro (a review for another day) and never had issues.
For $2,375 the Super-9 certainly isn’t cheap. Buying the fastest equipment is typically known as “free speed,” but nothing is free at that price. Of course the Super-9 wasn’t built with cost in mind; it was built for those seeking the ultimate speed weapon—a wheel that will get them from point A to point B (or in most races, back to point A) as fast as humanly possible. And it absolutely delivers on that. Of course the question we are asked most often is, “Would we buy one?” And when it comes to the Super-9, were we to be looking for a piece of equipment that would help ensure we had every legal advantage possible, it would absolutely be at the top of our list.