The mysterious new tire spotted on the front wheels of Decathlon AG2R riders at the Tour de France can now be revealed as the Continental Aero 111. It is the culmination of six years of research and development between DT Swiss, Swiss Side and Continental, with the aim of creating the ultimate wheel-tyre system, or the ‘world’s first aerodynamically optimized tire’.
As mentioned above, the tire has already been spotted out in the wild, most prominently on Decathlon AG2R’s new Van Rysel aero bike at the Tour de France. Well, we now have the details on this new aero road tire, so read on to find out more about the Continental Aero 111…
Combination of expertise and the ‘Vortex Generator’
As experts in their respective fields, Continental and DT Swiss called upon the services of Jean-Paul Ballard of Swiss Side, who originally worked as a senior engineer and head of concept design at BMW Sauber Formula One. There, he looked at tire aerodynamics and saw an opportunity to maximize the performance of the entire wheel system. Ballard and his team spent 10 years developing a successful tire, so his expertise in the Aero 111 project was immense.
Swiss Side set out to solve the rim-tire interface, or wheel-tire system. It all starts with the boundary layer of air directly on the surface. Airflow starts out laminar (smooth or regular) and then becomes turbulent, which sticks to the rim better, but you have to force it. Enter the Vortex Generators – a series of 48 evenly spaced cavities that allow airflow to stick and improve the performance of any bicycle wheel at all speeds up to 30 km/h.
“Aero performance suffers at lower speeds because the airflow does not stick to the edge. By improving the sail effect, drag can be reduced,” says Jean-Paul Ballard of Swiss Side.
“If the air doesn’t stick to the edge, the tire will come loose and stall, greatly increasing drag.”
Meet the Vortex Generators. This innovation was four years in the making. Everything from the shape, position, depth and number of tread impressions took a long time to develop to find the right balance – too much disruption and the air will separate, too little has no effect at all.
Although the tire is optimized for DT Swiss wheels, it improves the aerodynamics of any wheel.
Achieving the perfect balance
Contrary to current rhetoric, aerodynamics is not just about drag, it is also about handling, and the secret is to balance the two. The sail effect creates a lot of lateral force on the wheel, so the right balance between front and rear wheel makes the bike feel neutral and less jerky. This jerkiness is known as the “steering torque,” a result of the airflow not sticking to the rim and binding/unloading, causing that unstable feeling.
The Vortex Generators reduce stalling and on a windy day you don’t feel much discharge – you feel the wind pushing the wheel but the shaking is reduced. You also feel the sensation of being actively pushed forward.
At a yaw angle of 10-15 degrees, there is a saving of 3-6 watts at 30 km/h compared to the Continental Grand Prix 5000 ST R. At 45 km/h and a yaw angle of 15-20 degrees, the saving grows to 18 watts.
The tire works best with the following DT Swiss wheel systems: DT Swiss 1100 Dicut (80 mm, 60 mm, 50 mm and 38 mm), DT Swiss Dicut 1400 (80 mm, 60 mm, 50 mm and 38 mm), DT Swiss AR 1600 Spline 30 and DT Swiss AR 1800 Spline 30, DT Swiss ERC 1100 and 1400 Dicut (35 and 45) and DT Swiss ER 1600 Spline and 1800 Spline 30.
Tire composition and specifications
The Aero 111 uses the proven technology used on the Continental Grand Prix 5000 TR range, including Vectran Breaker puncture protection and tubeless-ready construction. The tire uses a modified version of the company’s race-honed BlackChili compound. The tire is available in two sizes only: 26-622 and 29-622, both of which are safe for use on hookless wheels up to 5 bar or 72 psi.
Tire weights are pretty much in line with the segment norms, with the 26mm weighing 250g and the 29mm 280g. Like the Continental GP 5000 ST R, the Aero 111 uses a two-ply 2/220 (two-ply 110 tpi) design.
Hannah Ferle, Road Product Manager, Continental, had this to say about the development: “With Aero 111, we’ve added a high-performance racing tire to our portfolio that does it all: it’s aero, it’s grippy and it’s fast. This collaboration has allowed us to expand our race-proven technologies and create a tire that’s unlike any other. Next time you encounter a crosswind, you’ll have no excuse not to be out in front.”
In terms of rolling resistance, the Continental Aero 111 was fastest when compared to the Schwalbe Pro One Aero 28c, Vittoria Corsa Speed TLR G+ 2.0 25c, Enve SES Road 25c, Cadex Aero Tubeless 25c, Pirelli P Zero Race TLR 25c and Schwalbe Pro One TLE 25c. There’s no data on how it performed against the brand-new Vittoria Corsa Pro Speed – we assume it wasn’t available at the time of testing. According to Continental, rolling resistance is on par with the ST R and TT R tires, while puncture resistance is the same as the latter.
What about tire wear and the effect that wear can have on the Vortex Generators? The tire has wear indicators – three small indentations of different sizes. According to tests conducted by Decathlon AG2R, the tire can go well into the second wear indicator without any negative impact. That’s over 2,000 km of riding. In terms of diminishing returns, there was also no significant reduction in aerodynamics.
Continental Aero 111: First Driving Impressions
I’ve had the tire for four weeks now and have used it for a total of four competitive time trials of 10 and 25 miles. As stated, it’s a front-specific tire and is best paired with a DT Swiss wheel. I mounted it to my DT Swiss Arc 1100 Dicut 80 wheel and kept the Vittoria Corsa Speed Pro on the rear disc.
I have to admit I was a little skeptical about the claims at first, but I was impressed after my first time trial with the tire – a 25-mile round trip from Lipkook, Hampshire.
With crosswinds prevalent for most of the race, the first thing I noticed was the improved stability of the front wheel. Normally in this scenario you would feel the wheel actively vibrate in gusts as the airflow is unloaded or stalled, but the wheel behaved exactly as JP Ballard described. I also found myself holding higher speeds on the rolling course and the combination of these two characteristics increased my confidence and ultimately my ability to push harder. I achieved a personal best time of 51 minutes and 27 seconds.
A week later, I tested the tire during an open 10-mile time trial, again on a brutally windy day that forced many competitors to withdraw. I rolled up to the start with a disc-brake rear wheel, admittedly a little apprehensive about my choice. Although I was nervous about relying on the front while resting my arms on the extensions, I managed to stay in the aero position for 99 percent of the way and came home with another personal best—this time 19 minutes, 40 seconds for 10 miles.
The next two time trials I did weren’t PBs based on distance, but they were PBs on the course. I ran another sub-20 minute time at a local club (10 minutes) and 20 minutes 13 seconds on the super grippy H10/8 course in Bentley, Hampshire.
It’s easy to dismiss claims based on manufacturers’ marketing hype, but the Continental Aero 111 does what it says on the tin: it’s fast, it’s stable, and most importantly, it gives the rider a level of confidence that time trialists crave in crosswind situations. While it won’t completely eradicate “steering torque,” it will dramatically reduce front wheel vibration while propelling you forward at higher speeds than ever before.
Prices and availability
The Continental Aero 111 tire is available globally starting today (July 3) and can be purchased exclusively from Bike24 (Europe), Competitive Cyclist (USA) and Swiss Side. Pricing is set at €119.95 / $120.95 USD.