AEROCROSS Wheels w/ SPOKE FINS
AEROCROSS™ wheels with SPOKE FINS™ streamline the round spoke, substantially reducing drag on the bicycle wheel itself—even in the presence of substantial crosswinds—while providing unmatched crosswind stability and safety to the cyclist in gusty wind conditions.
• Laminar Flow MINIMIZES Spoke Drag in Windy ConditionsMaintain low-drag laminar flow across the spoke even in crosswinds.• Unmatched Crosswind Stability Enhances Pedaling EfficiencyEnables aerobar position far longer under gusty crosswind conditions.• Crosswind-Induced Propulsion for Enhanced Drag ReductionFin-generated lift in crosswinds propels wheel for greater wheel efficiency.• Outperform ANY Aero Wheel in Strong CrosswindsBecoming the most cost-effective aero wheel for use in windy conditions.• Essential Drag Reduction for High Spoke Count WheelsFin lift propulsion in crosswinds further augments high spoke count wheel efficiency.
Patent US 9,290,041
AEROCROSS wheels with SPOKE FINS streamline the round spoke, substantially reducing drag on the bicycle wheel itself—even in the presence of substantial crosswinds—while providing unmatched crosswind stability and safety to the cyclist in gusty wind conditions. This non-obvious solution to reducing spoke drag was granted a patent on the first official office action in the USPTO, there being no quotable prior art of record to overcome. A companion patent for this invention is also now allowed, and due to issue soon in the European Patent Office.
Laminar Flow MINIMIZES Spoke Drag in Windy Conditions
SPOKE FINS convert the round spoke into an optimal aero-spoke that adjusts to the changing crosswind vector as the wheel rotates, automatically streamlining the spoke for any crosswind direction. This streamlined tailfin design reduces the drag coefficient of the round spoke by a factor around three to five (per Hoerner, Fluid-Dynamic Drag, 1965), and includes streamlining the critical spoke nipple.
SPOKE FINS on a round spoke outperform all bladed aero spokes in the presence of crosswinds. And importantly, SPOKE FINS maintain laminar flow across the spoke at far higher wind speeds than conventional aero spokes, further enhancing vehicle drag reduction under challenging wind conditions. (Flow transition from laminar to turbulent across the spoke immediately increases the drag coefficient thereon typically by a factor to two or more.)
Streamlined SPOKE FINS simply provide unmatched crosswind transparency to the wheel, being particularly effective when combined with traditional shallow rimmed wheels. Cyclists know that when cycling in windy conditions, a substantial crosswind is almost always present, making AEROCROSS wheels with SPOKE FINS the most stable and drag-efficient wheel possible for general use.
Judged functionally similar to a disk wheel, AEROCROSS wheels with SPOKE FINS have been deemed legal for Ironman triathlon, having first competed in an Ironman race in Arizona, October, 2018.
Indeed, AEROCROSS wheels with SPOKE FINS function similar to a disk or deep-rimmed wheel in streamlining wheel surfaces, but without the destabilizing effect of the deep rim, which can cause sudden destabilizing turning of the front wheel during sudden wind gusts. For cycling in windy conditions, AEROCROSS wheels with SPOKE FINS are simply the most stable and drag-efficient wheel possible for general outdoor use.
Unmatched Crosswind Stability Enhances Pedaling Efficiency
Since SPOKE FINS swivel about the spoke like a wind vane, drag reduction is maintained regardless of crosswind direction, yielding a smoother-riding high-performance aero wheel even in windy conditions. For example, being more stable than any other wheel, AEROCROSS wheels with SPOKE FINS allow the triathlete to remain in the aerobar position under challenging crosswind conditions far longer than conventional aero wheels with their deep rims. Thus, in windy conditions, the cyclist can remain far more efficient in pedaling, when he would otherwise need to lift out of the aerobar position for safety.
Crosswind-Induced Propulsion for Enhanced Drag Reduction
Pro cyclists are also reporting a propulsive effect from SPOKE FINS in crosswinds. When exposed to strong crosswinds while suspended on a bike stand, a wheel with SPOKE FINS tends to spin up forwardly. This is documented in several videos now posted online on YouTube.
The slightly retarded swiveling action of the fin about the spoke like a wind vane—in the changing crosswind vector with wheel rotation—causes a slight wing lift to be produced and applied to each spoke. This lifting force becomes particularly beneficial near the top of the wheel, where applied forces are actually magnified against counterforces applied at the axle, as also taught by the patent US 9,290,041.
Thus, this seemingly small applied lifting force can actually reduce the effective drag on the wheel, thereby further enhancing the efficiency of AEROCROSS wheels with SPOKE FINS under substantial crosswind conditions. Thus, cycling in windy conditions simply becomes a bit more efficient and faster.
And numerous downhill coasting tests—also documented online—demonstrate this effect in side-by-side comparisons against conventional aero wheels, where when the bikes approach the lower turn shown where exposed to greater crosswinds, the bike with AEROCROSS wheels with SPOKE FINS suddenly surges ahead. This suggests a dramatic change in the effective drag on the wheel, which at least in part is likely due to this propulsive lift effect in crosswinds demonstrated on the bike stand.
Given the apparent propulsive advantages from SPOKE FINS in crosswinds, under a sufficiently strong crosswind, it becomes likely that a higher spoke count wheel with SPOKE FINS will become more aerodynamically efficient than even a lower spoke count wheel having fewer SPOKE FINS. This condition simply defies industry conventional wisdom regarding wheel efficiency trends, and represents an exciting new development in aero wheel design. More testing is planned to further confirm this potentially astounding effect.
Outperforms ANY Aero Wheel in Strong Crosswinds
While only the most expensive aero wheels with hidden nipples have sometimes tested slightly faster than AEROCROSS wheels with SPOKE FINS, these deep-rimmed wheels are unmanageable for all but the most committed pro racers in windy conditions. So for most cyclists exposed to somewhat windy conditions, AEROCROSS wheels with SPOKE FINS simply deliver superior all round performance, while also becoming simply the most cost-effective aero wheel for general use.
Indeed, AEROCROSS wheels with SPOKE FINS are nearly as fast in no wind conditions than much more expensive carbon aero wheels, while also being more stable and manageable in windy conditions. AEROCROSS wheels with SPOKE FINS simply enable greater overall pedaling efficiency in windy conditions, minimizing the effort needed to maintain stable control while facing gusty crosswinds.
Essential Drag Reduction for High Spoke Count Wheels
Finally, with the recent trends toward disc brake wheels having greater spoke counts, SPOKE FINS become even more important, since greater spoke count wheels increase drag substantially. A 24-spoked wheel with SPOKE FINS becomes equivalent to a wheel with only eight spokes, thereby becoming substantially more aerodynamic than the stock 24-count wheel.
For stronger wheels with even higher spoke counts (32, 36, 48, for example) using SPOKE FINS becomes even more critical, as the overall wheel drag becomes even more heavily concentrated on the spokes compared to that on other tire and rim surfaces. Reducing spoke drag using SPOKE FINS on these high spoke count wheels used for heavier riders or for tandems is essential. And as a side benefit, the propulsive effect—mentioned above—in crosswinds then becomes even more substantial.