Reynolds RZR 46 Wheelset
- Item: REY0122 Actual Weight:"Actual Weight" means we weighed this item ourselves. 960 g
As aficionados of carbon fiber, Reynolds understands that you could care less what a governing cycling body says you should ride or not ride. You demand uninhibited speed and a light weight that screams up any climb. So, if this sounds up your alley, Reynolds basically created the RZR 46 Wheelset for you. At a mere 968 grams per pair, not even the Lightweight Gipfelsturm or Obermayer Gold compare in the weight category. And through implementing some of the most advanced aerodynamic technologies and designs on the market, Reynolds ensure that the RZR 46 stands completely peerless.
Now, we're going to be forward -- the complexity of the RZR design is deep, but we'll walk through it together. To start, we need to understand the prevalent ideology in aerodynamic wheel design, and to do so, we need to understand drag. What is it? Simply put, it's the restraining force that acts on the wheel when its direction of motion is counter to the free stream of airflow. Now, airflow near the surface of a wheel is turbulent by nature, and when it comes close to the rim surface, it becomes a turbulent boundary layer. This is the start of two kinds of drag, skin friction and pressure drag. Currently, wheel makers are attempting to harness the turbulent layer, reattaching it at the rear section of the rim. The reasoning behind this is that the system reduces pressure drag, but in return, the wheel sees gains in skin friction. However, this is viewed as a comprising trade off, as skin friction has around a ten-fold lower drag value than pressure drag.
To maximize this turbulent system, we've been seeing builders create a constant, rounded edge at the spoke face. For those attempting it, it's been viewed as a leap forward in design. However, Reynolds finds it to be counterintuitive. We'll explain. You see, the science of aerodynamics has developed almost as a case of supply and demand. As aviation technology develops, engineers are forced to develop more efficient airfoil designs, and these designs take the shape of what's called a NACA profile -- think of a stretched out tear drop shape. In recent years, though, some wheel designers have started to view the NACA profile as insufficient to the aerodynamics of wheels. The reasoning behind this is that while an airfoil only has what are called a leading and trailing edge, the rim's shape requires a trailing edge to double as a leading edge. Thus, we see the wide, rounded spoke faces of today. However, given that these systems rely on turbulence, Reynolds views this development as a step back from the proven designs of the airfoils that smooth turbulence. And this is just what the RZR 46 does with both its rim shape and what Reynolds is calling its Swirl Lip Generator (SLG).
At 20.8mm, the rim bed of the RZR 46 features a narrower width than the RZR 92's 28.0mm. Now, you're probably wondering why it's narrower? Well, simple logic tells us that a wider rim uses more material, and more material leads to a higher weight. However, the incorporation of SLG combines an aerodynamic advantage with a feathery overall weight. Essentially, the RZR 92's drastic width is used to counter the typical balloon effect, where the tire is wider than the rim. Under these conditions, turbulent airflow becomes even more turbulent and effectively raises drag. What SLG does for the 46 is to trick the introduction of airflow into thinking that it's encountering a wider rim. How? Basically, SLG is just a 0.9mm lip on the leading edge of the rim that smooths airflow as it passes to the tapered spoke face. And while it might sound a little primitive at its core, SLG tests at the A2 Wind Tunnel confirmed that it translates to a 12.5 second gain over a distance of 40 kilometers. Additionally, empirical testing showed that SLG reduces drag by 20% at a yaw angle of 10 degrees -- pretty impressive considering that Alphamantis, Inc. testing reflects that we spend the most time at 10 degrees during racing.
So, with SLG, drag is greatly reduced. However, Reynolds wasn't content with just this. In fact, Reynolds views the aerodynamic engineering of wheels as a four-part structure. 1) The wheel must be lightweight, yet structurally sound. 2) It must reduce turbulent airflow in order to create a low-drag system. 3) The aerodynamic efforts cannot compromise the steering and handling of the bike. 4) The wheel must generate an aerodynamic advantage from its lift-drag-ratio. Not surprisingly, one wheel rarely encompasses all of these traits. In fact, we find that article numbers Two and Three actually tend to contradict one another -- think of a disc wheel. However, at around 968 grams, and with one of the lowest drag systems on the market, the RZR 46 accomplishes all of the above harmoniously.
With the RZR, Reynolds also addressed an all-too-common ailment to carbon wheels -- poor braking. The solution was found through the development of what Reynolds calls its Crynogenic Glass Transition Braking System (CTg). Essentially, this is a patented braking design that required both a redesign of the brake track laminate and pads. Accordingly, CTg uses a temperature-conductive laminate at the brake track's transition points that withstands higher levels of heat than typical carbon laminates (around a 100 degree dispersion). And when paired with Reynolds' polymer Cryo Blue brake pads, braking becomes more predictable and requires less finicky feathering on fast descents.
It's impossible to not notice the RZR's carbon spokes and hubs. However, it is easy to miss that the rear hub features three hub flanges. The additional flange is positioned as to lie under the center point of the rim. So, while the radial spokes provide lateral support to the wheel, and the tangential spokes transfer torque from the hub to the rim, this 'torque flange' ensures that applied torque is pulled within the same plane as the rim's center. This increases efficiency over the standard two flange system, where the spokes pull the rim to the left or right plane with applied torque. For the spokes themselves, Reynolds not only used carbon fiber, but they're actually small airfoils -- a NACA 0033 airfoil, in fact. This designation means that the width is one-third of the length, but more importantly, it further reduces turbulent airflow over the wheel.
But, if you're feeling a little hesitant at the prospect of racing on carbon spokes (we remember the flexy titanium spokes, too), you can be assured that Reynolds spent a great deal of time protecting your investment. Typically, spokes encounter failure when deflection meets compression. However, the NACA 0033 spokes deflect around 12cm before abject failure, and within the RZR system design, Reynolds states that the spokes will not encounter anymore than 5mm of deflection. So, you're left with the added aerodynamics, rigidity, and ride quality without any drawback. Furthermore, the aforementioned traits have been further accentuated through the incorporation of Kevlar threads in the rim. And not only does this add strength and resistance to impact, but it also shaves off a good deal of weight.
The Reynolds RZR 46 Wheelset is available in the color Black with White labels and in a tubular configuration. Please note that the rear wheel is offered with either a Shimano or Campagnolo 11-speed freehub compatibility. Also, every wheelset includes two pairs of Reynolds Cryo Blue Brake Pads. Reynolds strongly recommends only using its proprietary pads, and the use of any other brake pads will result in a void of your warranty.