Wind Tunnel Showdown: 11 Super Cars Face Off (Part 1)
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The Results and Data for Each Bike
Using the baseline bike as our starting point, we first rank the bikes depending on their unweighted average CdA from tests at seven yaw angles. Every bike will display a line chart for simple viewing along with the unweighted average CdA values for the seven yaw angles.
We will then use this information to figure out the power needed to bike at forty km/h. With speed expressed in meters per second, the formula looks like this:
Power (W) = 0.5 × air density × CdA × speed³
In addition, we’ll calculate the time needed to complete 40 km at a steady power of 250W using this formula:
Speed (km/h) = 3.6 × ((Power / (0.5 × air density × CdA)) ^ 1/3)
Here, the air density is assumed to be a constant 1.2 kg/m³.
Baseline Model: Trek Emonda ALR 2015
My old bike with low-profile wheels, rim brakes, and external cable routing.
Specifications
Weight: 8.45 kg
Price: Approximately £300
Groupset: Shimano 105 R5800 Rim Brakes
Rider and Bike System
Average CdA: 0.3702
Power at 40 km/h: 304.67 W
Time for 40 km at 250 W: 01:04:05
Bike Only
Average CdA: 0.1370
Power at 40 km/h: 112.74 W
Time for 40 km at 250 W: 00:46:01
The baseline bike for our test is my own. I got it around 2017 as a winter training bike. I used it for about three years before it ended up in storage.
There are two reasons we chose this bike. First, it’s mine, so I can keep it in the same setup for future tests and use it as a consistent point of reference.
Second, it’s a good example of a basic, no-frills bike. It helps show how much power you could save by upgrading from a standard model to a high-performance aero racing bike.
Look Blade 795 RS
The French all-rounder bike, equipped with French wheelsets.
Specifications
Weight: 7.75 kg
Price: €9,790.00
Groupset: Shimano Dura-Ace
Rider and Bike System
Average CdA: 0.3478
Power Saved at 40 km/h: 18.38 W
Time Saved for 40 km at 250 W: 00:01:19
Bike Only
Average CdA: 0.1032
Power Saved at 40 km/h: 27.79 W
Time Saved for 40 km at 250 W: 00:04:09
This bike weighs 7.75 kg, not the lightest, but definitely not the heaviest either. However, in terms of aerodynamics, it’s the slowest among the superbikes we tested, ranking last in both tests.
While there’s room for discussion when considering the rider-bike system and potential margin of error, in the static tests of just the bike across seven yaw angles, it was slower than all the other bikes.
That said, it’s still much faster than our baseline model. As our review of the Look 795 Blade RS shows, a bike’s performance is more than just aerodynamic data. When factoring in the rider system, this bike can still save between 10.57 and 26.19 watts. It’s also worth noting that Look itself emphasizes that “efficiency,” not just aerodynamics, was the design goal for this bike.
Giant Propel Advanced SL0
Dedicated aerodynamic water bottle cage and flat spokes.
Specifications
Weight: 7.5 kg
Price: €11,999.00
Groupset: Shimano Dura-Ace
Rider and Bike System
Average CdA: 0.3438
Power Saved at 40 km/h: 21.67 W
Time Saved for 40 km at 250 W: 00:01:33
Bike Only
Average CdA: 0.0959
Power Saved at 40 km/h: 33.81 W
Time Saved for 40 km at 250 W: 00:05:09
By definition, the Propel is Giant's dedicated aerodynamic racing bike, alongside the lightweight TCR as a high-performance counterpart.
The TCR is somewhat limited by the UCI's 6.8 kg weight rule, focusing more on improving the mechanical structure and aerodynamic performance. On the other hand, the Propel, launched last year, aims to address the challenge of reducing weight while enhancing aerodynamics. In the coming years, these two models are likely to merge.
That said, Giant's design approach for the Propel used a dynamic rider-bike model, rather than measuring the bike as a standalone item. This method is more aligned with real-world riding conditions and provides a better fit for the rider's actual experience.
Trek Madone SLR 7 Gen 8
It features an aerodynamic water bottle cage and iconic hole design.
Specifications
Weight: 8.16 kg
Price: £8,500.00
Groupset: SRAM Force AXS
Rider and Bike System
Average CdA: 0.3406
Power Saved at 40 km/h: 24.31 W
Time Saved for 40 km at 250 W: 00:01:45
Bike Only
Average CdA: 0.0954
Power Saved at 40 km/h: 34.19 W
Time Saved for 40 km at 250 W: 00:05:13
The latest Madone is the result of Trek combining its lightweight Emonda and aerodynamic Madone into a single bike. Trek claims that it performs better in wind tunnel tests than the soon-to-be-discontinued first-generation aerodynamic Madone.
Trek acknowledges that this is largely due to the aerodynamic water bottle cage, and we assume that anyone purchasing this bike would also buy the matching water bottle cage, which is why we included it in this test.
Like the Propel mentioned above, the Madone is another bike that performs better with a rider than without.
Van Rysel RCR Pro
This "affordable" bike has made a big splash in the World Tour.
Specifications
Weight: 7.54 kg
Price: £9,000.00
Groupset: Shimano Dura-Ace
Rider and Bike System
Average CdA: 0.3438
Power Saved at 40 km/h: 21.69 W
Time Saved for 40 km at 250 W: 00:01:33
Bike Only
Average CdA: 0.0936
Power Saved at 40 km/h: 35.70 W
Time Saved for 40 km at 250 W: 00:05:29
I apologize for calling the £9,000 budget "affordable"—it’s still quite a hefty price for a bike. However, Van Rysel has really tried to make value for money a core aspect of its brand.
When its parent company, Decathlon, became the title sponsor of the French World Tour team Decathlon AG2R La Mondiale, the brand suddenly gained a lot of attention.
Compared to the competition here, the value for money is indeed impressive. With the top-tier Dura-Ace groupset, the Van Rysel is £299 cheaper than the Canyon Aeroad CFR, which is a direct-to-consumer bike of the same specs.
Despite the lower price, the performance is by no means compromised. Both the aerodynamics and weight are within reasonable ranges. The aerodynamic performance is slightly on the lower end, but the weight is just 7.54kg, which is pretty impressive.
Specialized S-Works Tarmac SL8
The lightest model also performs the best during riding.
Specifications
Weight: 7.18kg
Price: £12,000.00
Groupset: SRAM Red AXS
Rider and Bike Total System
Average CdA: 0.3404
Power Saved at 40km/h: 24.47
Time Saved at 250w for 40km: 00:01:46
Bike Only
Average CdA: 0.0917
Power Saved at 40km/h: 37.23
Time Saved at 250w for 40km: 00:05:45
Launched in 2023, the Specialized S-Works Tarmac SL8, fitted with the new SRAM Red AXS groupset, made news with its prominent head tube labeled the "speed detector."
Arguably among the most beloved bikes among fans is the Tarmac. For example, the excitement for this new bike was so strong a week before it was unveiled that almost all of Specialized's marketing materials were hacked and leaked.
Although only 7.18 kg with pedals and a bottle cage, this bike is the lightest in our test; its aerodynamic performance was poor. Although it came seventh on our test, given the margin of error, it might actually rank third.
Pinarello Dogma F
The most expensive bike in the test.
Specifications
Weight: 7.20kg
Price: £12,500.00
Groupset: Shimano Dura-Ace
Rider and Bike Total System
Average CdA: 0.3444
Power Saved at 40km/h: 21.24 W
Time Saved at 250W for 40km: 00:01:32
Bike Only
Average CdA: 0.0915
Power Saved at 40km/h: 37.47 W
Time Saved at 250W for 40km: 00:05:48
The Dogma F was launched just before the 2024 Tour de France, reportedly reducing its weight by 108g, with half of the weight savings coming from the new integrated handlebar. The new model features a longer wheelbase, 30C tire clearance, and an improved drag coefficient by 0.2%. Specifically, the CdA difference is approximately 0.00027 kg/㎡, which equates to about 0.28W at 40 km/h.
In our test, due to the closed thru-axle hole on the rear stays, we had to use an additional mounting plate to install the Dogma F. This might have added a small amount of drag, though we couldn’t determine the exact impact.
The Dogma is also one of the lighter bikes in our test, with a weight of 7.20kg.
Cannondale SuperSix Evo 4
EF team's race bike, equipped with an aerodynamic water bottle cage and the best paint job.
Specifications
Weight: 7.69kg
Price: €12,500.00 (Lab71)
Groupset: Shimano Dura-Ace
Rider and Bike Total System
Average CdA: 0.3442
Power Saved at 40km/h: 21.37W
Time Saved at 250W for 40km: 00:01:32
Bike Only
Average CdA: 0.0905
Power Saved at 40km/h: 38.28W
Time Saved at 250W for 40km: 00:05:57
I know this review is supposed to focus on specific data comparisons, but allow me to say this: the SuperSix Evo 4 in this color scheme is the best-looking bike in the bunch.
For the test, we received a team edition Hi-Mod model with a Dura-Ace groupset. This bike is built on the Lab71 frame and is the most expensive in this lineup, priced at a staggering £12,500.
Considering that the SuperSix Evo isn’t even Cannondale’s dedicated aero bike, its performance is impressive. It ranked fifth in our test, and with the margin of error, it could even take second place. That said, the margin of error could go the other way, dropping it as low as seventh.
Canyon Aeroad CFR
Great value for money, equipped with an integrated handlebar with adjustable width and height.
Specifications
Weight: 7.76kg
Price: £9,299.00
Groupset: Shimano Dura-Ace
Rider and Bike Total System
Average CdA: 0.3428
Power Saved at 40km/h: 22.54W
Time Saved at 250W for 40km: 00:01:37
Bike Only
Average CdA: 0.0904
Power Saved at 40km/h: 38.31W
Time Saved at 250W for 40km: 00:05:57
Canyon found that its average speed is slightly faster than the Tarmac SL8 and performs better than the Cervélo S5 at higher yaw angles, while the Cervélo has a slight edge at zero yaw. These results align with our measurements, but due to potential errors, we can’t guarantee this is the case in every scenario.
The Aeroad CFR offers excellent value for money. Although it’s slightly more expensive than the Van Rysel, its integrated handlebar with adjustable width and height can save you a lot of extra costs and hassle when making adjustments later on.
This bike is Canyon’s dedicated aero model, launched alongside the lighter Ultimate CFR. Its weight is similar to the Look Blade 795 RS and about 740g lighter than the Cervélo equipped with the Force AXS groupset. Like Giant’s Propel/TCR combination, we also predict that these two Canyon models may merge into one in the next few years.
Cervélo S5
The heaviest, but the fastest at zero yaw angle.
Specifications
Weight: 8.5kg
Price: £9,599.00
Groupset: SRAM Force AXS
Rider and Bike Total System
Average CdA: 0.3418
Power Saved at 40km/h: 23.38W
Time Saved at 250W for 40km: 00:01:41
Bike Only
Average CdA: 0.0900
Power Saved at 40km/h: 38.66W
Time Saved at 250W for 40km: 00:06:01
The Cervélo S5 is undoubtedly a dedicated aero bike, featuring a unique integrated handlebar, ultra-flat tubing, and a design that wraps around the rear wheel. However, it’s not exactly lightweight. Considering that the test model is equipped with Force AXS rather than the lighter Red groupset, this might be a slightly unfair comparison. Even so, it is still 340 g heavier than a similarly specced Madone.
The Visma-Leasea Bike team has crossed many finish lines with the S5, although two-time Tour de France champion Vingegaard often opts for the lighter R5 during mountain stages.
In our test, the S5 is one of only three bikes that could potentially take first place, considering the margin of error. That said, if the error swings the other way, it could drop as low as seventh place.
Scott Foil RC Pro
Scott's dedicated aero bike
Specifications
Weight: 7.87kg
Price: £10,499.00
Groupset: Shimano Dura-Ace
Rider and Bike Total System
Average CdA: 0.3441
Power Saved at 40km/h: 21.48W
Time Saved at 250W for 40km: 00:01:33
Bike Only
Average CdA: 0.0897
Power Saved at 40km/h: 38.90W
Time Saved at 250W for 40km: 00:06:03
There are rumors that a new Scott Addict "all-rounder" may be released in the near future, but we haven’t seen any teasers yet. Riders from the DSM-Firmenich-Post NL team are still using the Foil aero bike.
Weighing 7.87kg, it’s unlikely to be affected by the UCI minimum weight rule anytime soon. Given its primary focus on speed over flat terrain, this weight isn’t likely to draw much attention. In our test, considering the margin of error, it has a chance of taking first place. However, if the margin swings the other way, it could drop to seventh.
Factor OSTRO VAM
Specifications
Weight: 7.23kg
Price: £10,750.00
Groupset: Shimano Dura-Ace
Rider and Bike Total System
Average CdA: 0.3407
Power Saved at 40km/h: 24.25W
Time Saved at 250W for 40km: 00:01:45
Bike Only
Average CdA: 0.0882
Power Saved at 40km/h: 40.15W
Time Saved at 250W for 40km: 00:06:17
In our bike test, the Factor OSTRO VAM proved to be the fastest bike and the second lightest, just 50g heavier than the Tarmac SL8. Even considering the margin of error, it consistently ranks among the top three. Only Cervelo and Scott have a chance to surpass it in certain scenarios. For a relatively small brand, this result is quite impressive.
Moreover, we didn’t use the brand’s own aerodynamic water bottle cage during the test. With it installed, the bike could potentially perform even better. We recently interviewed the brand’s founder and CEO, Rob Gitelis, who shared insights into his career, the birth of Factor, and his loyalty to his employees during the pandemic.
That loyalty seems to have paid off, as reflected in the performance of this remarkable bike.
Conclusion
Our conclusion is that there are some interesting differences among the bikes in the test. When considering the rider and bike total system, the differences are minimal, within a very narrow range. However, if your budget allows, you can still gain a few watts of power advantage by choosing the right bike.
Overall, when deciding to upgrade, factors like weight and ride quality may be more important than saving a watt or two.
What Have We Learned?
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Aerodynamics Isn’t Everything
When comparing bike performance, aerodynamics often takes priority. However, one key takeaway from this test is that once your bike is within this performance range, you should start focusing on other aspects. Whether it’s weight or color doesn’t really matter—just choose what suits you best. -
Consider Upgrading Your Helmet First
In our previous helmet test, the POC Procen Air was the top performer, saving 12.76W at 40km/h compared to the slowest helmet in the test.
In the wheelset test, the DT Swiss ARC 1100 Dicut with a 62mm rim height was the winner, saving 3.87W at 40km/h compared to the slowest wheelset in the test. It’s worth noting that the “slowest” here refers to a high-quality aero wheelset from Reserve.
According to our wind tunnel data, the difference between the Tarmac SL8 and the baseline Emonda is 24.47W. However, compared to the new Look Blade 795 RS, the least aerodynamic bike in this test, the difference is only 6.09W. Power differences of about 3-4W are the smallest that can be physically felt, and even then, only during continuous riding.
When a helmet that costs a few hundred or a thousand dollars can save nearly as much power as a frame or wheelset costing tens of thousands, it makes sense to prioritize the helmet first.
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You Don’t Have to Be a Pro to Ride a Fast Bike
Our test calculated power savings at 40km/h, but the CdA values can be extrapolated to other speeds as well.
Most amateur riders can maintain a speed of 30km/h for extended periods, and the differences at this speed remain significant. Upgrading from the Trek Emonda ALR to the fastest bike in the test could save you 7.03 to 13.62W. Even for non-professional riders, this is a noticeable improvement.
Recommended Reading
- Wind Tunnel Showdown: 11 Super Cars Face Off (Part 1)
- Beginner's Guide: A Complete Breakdown of Mainstream Road Bike Groupset Levels
- Beginner's Guide: Detailed Explanation of Front Derailleur Types, Installation, and Compatibility
- Beginner's Guide: Everything You Need to Know About Cassettes
- A Comprehensive Guide to Rear Derailleurs