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Cadex has carved out an identity for itself as a wheel brand in a few short years, creating lightweight, aero wheels with an immediately identifiable carbon-spoked design. The brand’s latest release, the 50 Ultra Disc Wheel System, adopts hookless rims and redesigned aero hubs to create an impressively feathery package that’s efficient beyond just aerodynamics.
A system approach to wheel design
Aerodynamics is only one piece of the wheel efficiency puzzle, and much like Zipp with its Total System Efficiency design approach, Cadex is looking for speed across a variety of areas, including reducing losses from the tires and improving hub efficiency, along with lowering weight.
Every component of the 50 Ultra Disc wheels is created to go together, from the rims to the hubs and even the bladed carbon spokes that tie them together. By designing every part of a wheelset, instead of just the rims, or just the rims and hubs, Cadex says it has more control over the final product, delivering better ride quality and more control over factors like aerodynamics and weight.
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To reach its performance goals for the 50 Ultra Disc, Cadex is turning to hookless rims, a feature that’s becoming increasingly common for road wheels. This style of rim has a couple main benefits. First, it can be made lighter than traditional hooked rims, where, as the name implies, hooks hold the tire bead in place. Secondly, they provide better sidewall support to tubeless tires, meaning they can be run at lower pressures for a more comfortable ride, and one that is faster too thanks to higher volume tires run at lower pressures having a smaller contact patch.
Cadex has also designed the profile of the 50 Ultra wheels to be more aerodynamically efficient, while an increased rim bead width of up to 3.8mm helps create a rounder tire shape, which Cadex claims helps with tire grip and wheel handling. The 22.4mm internal rim width works best with tires in the 25mm to 32mm range says Cadex.
Cadex has rolled out a brand new set of aero hubs, called R3-C, for the 50 Ultra Disc, and they carry some pretty impressive claims. Between the aero profile, the all-new low-friction freehub, and ceramic bearings and Cadex says the hubs reduce power loss by a whopping 30%.
Carbon spokes for stiffness, and low weight
Bladed carbon spokes are something of a Cadex trademark at this point, and are one of the first things visually most people notice about the brand’s wheels. But they’re not just for looks. The high-tensile-strength Super Aero carbon spokes are laced to the wheels with something Cadex calls Dynamic Balanced Lacing, which uses a wider bracing angle to even out spoke tension under pedaling forces. The spokes themselves help increase lateral stiffness as well, resulting in a final package that is a claimed 18.8% stiffer than the Zipp 454 NSW and 40.6% stiffer than the Roval Rapide CLX.
The spokes also lightweight and bladed for yet another aerodynamic advantage.
Cadex doesn’t just wind tunnel test its wheels — it tests them against competitors like Zipp ENVE, Roval, and DT Swiss; with the brand’s own tires and different brands’ tires; and on different leading aero bikes from Giant, Cervélo, Specialized, and Canyon to ensure they’re fast no matter what bike or tire they end up being ridden with.
By Cadex’s wind tunnel testing at 40 kph across yaw angles from -20-degrees to +20 degrees, the 50 Ultras best the competition by a modest 0.15 watts compared to the ENVE SES. 5.6, and up to 1.5 watts over the Zipp 454 NSW when all using the same Cadex Aero 25c tires. It’s not ground breaking, but it is an advantage over some of the fastest known wheelsets at the approximately 50mm depth.
The hubs, rims, and spokes all come together to bring the weight impressively low for a 50mm-depth wheel, to a level we could have only dreamed of with tubular tires at shallower rim depths in the past.
The total weight for the set is 1,349 grams, says Cadex, 595 grams up front and 754 grams in the rear.
The new wheels compete with other top-end 50mm options on the market in pricing as well. The set costs $3,500 — $1,500 for the front and $2,000 for the rear.
Check back in to VeloNews soon for a full in-depth review.