Aerodynamics has been the most crucial innovation in road bikes in recent years, from frames to wheelsets. We are familiar with the pneumatics of the frame, but we are still using frame height to judge the pneumatics of the wheelset, which is not the case in reality. Aerodynamic wheels have evolved over three generations, from the original V-shape to the U-shape to the UV-shape; the V-shape has been phased out because of its lower resistance to frontal winds, and the U-shape is the so-called "fat rim," which is more stable in terms of sail effect and crosswind stability compared to the V-shape. Compared to the V-shaped wheel, the U-shaped wheel is a step forward in terms of "sail effect" and crosswind stability. However, the pursuit of aerodynamics is endless, the wheel shape has evolved to UV shape, of course, UV shape is just a metaphor, the cross-section shape of the wheel of each major brand is not quite the same, representing different design concepts. However, all of them utilize a lot of CFD calculations and are verified through wind tunnel tests. The aerodynamic performance of the new UV-shaped wheels can even exceed that of the larger frame height U-shaped wheels, so it is no longer accurate to judge aerodynamics by frame height.
ICAN AERO 52 WD Disc
ICAN Aero Disc series are the most cost-effective, high-performance wheels from ICAN. Drawing upon the success of their previous Fast and Light series, the Aero wheels utilize an advanced carbon fiber layup and aerodynamic design to deliver unmatched performance. With a 30mm outer width and 21mm inner width, the rims are engineered for minimum aerodynamic drag. Their tubeless compatibility from 25-40mm also supports the fastest tires.
Shimano Dura-Ace Wheelset
The latest generation of Shimano wheelsets is no small step forward. In order to find the rim shape that minimizes aerodynamic drag and is less susceptible to side winds for each model, Shimano uses CFD for analysis and AI for rim design. The AI searches for wheel shapes so that they can be analyzed on a large scale, including shapes that a human designer would never be able to come up with. This reminds us of the recently popular ChatGPT, wouldn't it be possible to design a super aerodynamic wheelset with deep learning and training.
The C36, C50, and C60 all have the same inner (21mm) and outer (28mm) rim widths so that the same tires fit the same way. The cross-section of the rims looks like a standard "UV" shape, but this was achieved through AI-assisted design, taking into account both aerodynamics and stability.
Bontrager Aeolus RSL Wheelset
The new generation of Bontrager Aeolus RSL wheelsets are designed to a very high standard. Previously, Bontrager's optimization process was carried out in 2D mode, but the 3D CFD methodology used in the design of the Aeolus RSL allows for the precise calculation of the subtle traction forces generated by the wheelset in different directions, at different levels, and in different parts of the wheelset. With this new approach, Bontrager was able to better replicate real-world conditions, adjust the design accordingly, and optimize aerodynamics and rolling resistance. The result is the Aeolus RSL, the fastest wheelset Bontrager has ever built.
The Aeolus RSL 51, 62, and 75 have the same inner (23mm) and outer (31mm) rim widths, with the larger inner widths allowing the tires to expand rounder, providing a better aerodynamic connection to the tire, and better comfort.The Aeolus RSL 37 has a different inner (21mm) and outer (28mm) rim width, optimized for a lower frame height. The Aeolus RSL wheels have a more "pointy" looking cross-section, which is related to the larger outer width.
Zipp Hookless Tubeless Tire Wheelset
Unlike other brands, Zipp's trick to making you faster is TSE (Total System Efficiency), which takes into account not just wind resistance, but gravity, roll resistance, and vibration losses. That's why Zipp has embraced low-pressure, hookless tubeless tires and a wider inner rim width, and Zipp has a "one-of-a-kind" technology, the Bionic Wave rim, which combines the aerodynamics of a high-frame wheelset with the stability of a low-frame wheelset (the 454 NSW with the Wave rim saves about 6 watts of power compared to the 404 Firecrest), and a "one-of-a-kind" technology, the Bionic Wave rim. Golf ball potholes provide an aerodynamic edge effect by delaying vortex shedding from the rim surface.
The 454 NSW and 404 Firecrest rims are 23mm wide on the inside and 28mm wide on the outside without the lip hooks, which is considerably narrower than the Bontrager Aeolus RSL with the same inside width, so the 454 NSW and 404 Firecrest rims don't look quite so "pointy" in cross-section. The cross-section of the 454 NSW and 404 Firecrest wheels looks less "pointy".
ENVE 4th Generation SES Wheelset
ENVE also embraces hookless tubeless tires, and their signature wheelset is the Smart ENVE System (SES) series, built on ENVE's real-world, fast design philosophy. The airflow at the front of the bike is different from the airflow at the back of the bike, and all of the wheelsets in the SES series have frame heights and shapes that are specifically designed for the flow field in which they ride. The front frame height is smaller than the rear and has a more rounded profile to maximize crosswind stability and control, while the rear frame height is taller and more streamlined to maximize power transfer and minimize drag. the SES wheelsets were designed and tested for speeds of 48km/h and 32km/h, respectively, resulting in rim shapes that deliver best-in-class performance at both real-world speeds.
Taking SES 4.5 as an example, although the front and rear wheel frame heights are different, they have the same inner width (25mm) and outer width (32mm), so it can be said that the inner width is very aggressive and can only be used with tires above 28c, which of course can easily reach the maximum tire pressure of 73psi for hookless tubeless tires.ENVE's rims have thicker sidewalls, which is more sturdy and snake-bite resistant, so the outer width can reach 32mm without the tire lip hooks. The ENVE wheels are thicker on the sidewalls, stronger and more resistant to snakebites, so the outside width can still reach 32mm without the tire lip hooks, making the front wheels look fatter and the rear wheels look thinner.
DT Swiss ARC 1100 DICUT Wheelset
The ARC 1100 DICUT is DT Swiss' top of the line aerodynamic wheelset with the highest level of technology.ARC stands for Aerodynamic, Race, Carbon, and 1100 means the use of 180 DICUT hubs, SINC ceramic bearings, and the Ratchet EXP ratcheting system.The DICUT is the lightest, stiffest, and most aerodynamic hub-and-spoke system available from DT Swiss and is aimed at road racing and track riding. Road racing and track riding, where speed is their primary concern, and very high tension can be maintained with custom spoke heads.
DT has been developing wheelsets with aerodynamic specialists Swiss Side since 2016, and DT's aerodynamic wheelsets excel in both aerodynamics and stability.The rims of the ARC 1100 DICUT DB 80, 62, and 50 are designed very differently, with an inner width of 20mm, but outer widths of 32mm, 27mm, and 26.5mm, respectively, which is why the ARC 1100 The ARC 1100 DICUT DB 80 and 62 and 50 have different rim designs, with an inner width of 20mm but an outer width of 32mm, 27mm and 26.5mm respectively.
Roval Rapide CLX Wheelset
The Roval Rapide CLX is a different kind of wheelset, with lightning engineers using an out-of-the-box design with the goal of ensuring stability and speed in a high-frame aerodynamic wheelset. the Rapide CLX has an "amazing" 35mm outside front wheel width and 51mm frame height, with a distinctly truncated (and blunted) profile, and 25% more stability in crosswinds than the CLX50, the most stable wheelset on the market over 50mm frame height. The Rapide CLX front wheel is an "amazing" 35mm wide and 51mm tall, with a significantly shorter (and blunter) profile, which is 25% more stable in crosswinds than the CLX50, and is the most stable wheelset on the market with a frame height of over 50mm. The rear wheel is 60mm taller and has a more "pointed" profile, optimized for wind resistance. The Rapide CLX is the best interpretation of the aerodynamic concept and does everything possible to optimize the design. The front wheel is 35mm wide, the rim sidewalls are thicker, and it is hollowed out for lightness. The first generation of Rapide CLX did not recommend the use of tubeless tires to ensure reliability. The Rapide CLX II has been re-tooled with a carbon fiber stack design that dramatically improves the test standards, and although the weight has increased a bit, at 1500 grams it is still very light.
Despite the wide outer width, the Roval Rapide CLX wheels are only 21mm wide on the inside, fitting 25 or 26mm tires. The front wheel is obviously fatter, but if you scale it down, the frame height is about 37.5mm if the outer width is 28mm, are you thinking of the Bontrager Aeolus RSL 37, maybe their crosswind stability is similar.BX Jun used the Roval Rapide CLX for a long time, and it will be ridden on a gusty day as well, and the stability is really impressive.
Now we all know better, the most technical part of the wheelset is the rim, and the major brands invest a lot of resources and time in research and development, and each has its own focus. It's time to shift the focus of the wheelset from weight to aerodynamics, because a hundred grams lighter is nowhere near as good as a more aerodynamic and stable experience.