The mysterious new tire that was spotted on the front wheels of the Decathlon AG2R riders at the Tour de France can now be revealed as the Continental Aero 111. It represents the culmination of six years of research and development between DT Swiss and Swiss Side. and Continental, with the goal of creating the ultimate wheel and tire system or “the world’s first aerodynamically optimized tire”.
As mentioned above, the tire has already been spotted in the wild, most notably on the new Van Rysel Decathlon AG2R aero bike at the Tour de France. Well, now we’re down on this new aero road tire, so read on to find out more about the Continental Aero 111…
A combination of expertise and “Vortex Generator”
As experts in their fields, Continental and DT Swiss enlisted the services of Swiss Side’s Jean-Paul Ballard, who originally worked as a senior engineer and head of concept design at BMW Sauber Formula 1. It was there that he looked at the aerodynamics of the tires and saw an opportunity to maximize the performance of the complete wheel system. It took Ballard and his team 10 years to develop a successful car tire, so his experience with the Aero 111 project was vast.
Swiss Side’s goal was to solve the rim-tire interface, or the wheel-tire system. It all starts with the boundary layer of air right at the surface. The airflow starts laminar (smooth or regular) and then becomes turbulent, which sticks to the rim better, but you have to force it. That’s where the Vortex generators come in – a series of 48 evenly spaced cavities that release air flow to stick and boost the performance of any bicycle wheel at all speeds up to 30km/h.
“Aero performance suffers at lower speeds because the airflow doesn’t stick to the rim. By increasing the gliding effect, drag can be reduced,” says Jean-Paul Ballard of Swiss Side.
“If the air doesn’t stick to the rim, it separates and stalls, and the drag increases significantly.”
Enter the Vortex Generators. This innovation took four years of work. Everything from the mold, shape, position, depth and number of treads took a long time to find the right balance – too much interference and the air separates and too little has no effect at all.
Although the tire is optimized for DT Swiss wheels, it will improve the aerodynamics of any bike.
Achieving the perfect balance
Contrary to current rhetoric, aerodynamics is not just about drag, it’s also about handling, and the secret lies in balancing these two attributes. The gliding effect creates a lot of lateral force on the bike, so having the right balance between the front and rear wheels helps the bike feel neutral and jerk less. This jerking is known as “steer torque” which is the result of airflow not sticking to the rim and stalling/relieving, causing an unstable feel.
Vortex generators reduce lock-up and on a windy day you don’t feel too much unloading – you feel the wind pushing the wheel but the shock is reduced. You will also feel the sensation of being actively pushed forward.
So at 10-15 degrees of roll 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 at 15-20 degrees of roll the saving increases. at 18 watts.
The tire works best with the following DT Swiss wheel systems: DT Swiss 1100 Dicut (80mm, 60mm, 50mm and 38mm), DT Swiss Dicut 1400 (80mm, 60mm, 50mm and 38mm), 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 compound and specifications
The Aero 111 uses proven technology used in the Continental Grand Prix 5000 TR range, including Vectran Breaker puncture protection and tubeless construction. The tire uses an improved version of the company’s BlackChili racing compound. The tire is only available in two sizes – 26-622 and 29-622, both of which are safe to use on hookless bikes up to 5 bar or 72 psi.
Tire weight is quite comparable to segment standards: the 26mm weighs 250g and the 29mm 280g. Like the Continental GP 5000 ST R, the Aero 111 uses a 2/220 dual ply (110tpi dual ply).
Hannah Ferle, Road Product Manager, Continental, had the following to say about the development: “With the Aero 111, we’ve added a high-performance road tire to our portfolio that can do it all: it’s aero, grippy and fast. This collaboration has allowed us to expand our already race-proven technology and create a tire unlike any other. The next time you hit a crosswind, you’ll have no excuse not to go ahead.”
In terms of rolling resistance, the Continental Aero 111 tested fastest against 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 25 . There’s no word on how it fared against the all-new Vittoria Corsa Pro Speed - we assume it wasn’t available at the time of testing. According to Continental, rolling resistance is comparable to the ST R and TT R tires, while puncture resistance is the same as the latter.
What about tire wear and the effect of wear on Vortex Generators? The tire has wear indicators – three small indentations of different sizes. According to tests carried out by Decathlon AG2R, the tire can go well into the second wear indicator without negative impact. That’s over 2000 km of driving. As for diminishing returns, there hasn’t been a significant reduction in aerodynamics either.
Continental Aero 111: first driving impressions
I’ve had the tire for four weeks now and have used it in a total of four competitive time trials at 10 and 25 miles. As stated, it’s a front wheel specific tire and pairs best with a DT Swiss bike. I mounted it on my DT Swiss Arc 1100 Dicut 80 bike and kept the Vittoria Corsa Speed Pro on the rear disc.
I’ll admit I was a bit skeptical of the claims at first, but after my first time trial with the tire I was impressed – a 25 mile round trip in Lipkook, Hampshire.
With the crosswind underlining most of the race, the first thing I noticed was the improved stability of the front wheel. Usually in this scenario you can feel the bike actively jerking in gusts when the airflow is released or stopped, but the bike behaved exactly as JP Ballard described. I also noticed that I held higher speeds on the rolling track and the combination of these two attributes boosted my confidence and ultimately my ability to push harder. I managed a PB of 51 minutes and 27 seconds.
A week later I tested the tire in an open 10 mile time trial, again on a horrendously windy day that forced many competitors to retire. I started with the rear disc wheel on as I was a bit apprehensive about my choice. While I felt jittery from trusting the front end while resting my hands on the risers, I managed to stay aero for 99 per cent of the course and came home with another PB – this time 19min 40sec for 10 miles.
While the other two time trials I attempted weren’t distance based PBs they were course personal bests with another under 20 at the local club 10 and 20min 13sec on the super grippy H10/8 track in Bentley, Hampshire.
It’s easy to dismiss claims based on manufacturers’ marketing propaganda, but the Continental Aero 111 does what it says on the tin – it’s fast, stable and, importantly, instills the level of confidence that time trialists crave in crosswind situations. While this won’t completely eliminate “steer torque”, it will drastically reduce front wheel jerk while propelling you to higher speeds than before.
Price and availability
The Continental Aero 111 tire is available worldwide from today (July 3) and can be purchased exclusively from Bike24 (Europe), Competitive Cyclist (USA) and Swiss Side. The price is set at 119.95 EUR / 120.95 USD.