STRADA: Reinventing The Aero Road Bike
3T has done it again, reinventing the aero road bike from scratch with the STRADA. But “aero road” doesn’t do it justice, as it’s not just extremely aero but also very comfortable. How can one bike be both? The key elements are tire size optimization and a paradigm shift for the drivetrain, combined with a lightbulb moment designing new aero shapes.
WIDE TIRE OPTIMIZATION
The biggest factor in road bike comfort are the tires; they provide more compliance than any other part of the bike. Wider tires are better at reducing shocks from cracks, curbs, cobbles and potholes, which is why they are the norm at Paris- Roubaix. Wider tires also have lower rolling resistance, because their shorter contact patch requires less bending by the casing.
In addition, wider tires offer an advantage on long and multi-day rides, reducing the steady drain on a rider’s energy level caused by high-frequency road buzz. But aerodynamics are also important on such rides, and wide tires tend to test poorly in the wind tunnel. However that is to be expected if you test them with frames and parts optimized for narrow tires. The STRADA is the first aero road frame optimized for wider tires, so finally you can be fast and comfortable all the time, from the cobbles to the climbs. All day, every day, with one and the same bike.
PARADIGM SHIFT: 1xAERO
With all aero road bike developments of the past 20 years, the drivetrain was never really tackled. So 3T did. The worst area aerodynamically is around the BB, with the frame, crank, chainrings, front derailleur, water bottles and rider’s legs leaving little room for the air to pass through. A single ring drivetrain eliminates the front derailleur and one chainring, reducing frontal area, creating space for unobstructed airflow and freeing up the design of the seattube to shield the rear wheel even better (no front derailleur mount needed). And with modern cassettes (in particular the special 3T cassette coming soon), you still have all the gears you need.
Think about it, 30 years ago we had 12 gears (2x6) of which only 8 were unique (the rest overlapped). Now we’re at 2x11, always assuming that more is better. But did the “improvement” from 2x10 to 2x11 really make that much of a difference? Sometimes more is not better, it’s just more; more weight, more drag, more gear overlap and more complexity. So instead of 2x11 with 14 effective gears, a front derailleur, a second ring and a second shift lever, 1x11 gives you the gears you need, the range you need, fewer components, less weight, less drag and less hassle.
3T designs for real world aerodynamics at realistic speeds. Sometimes that clashes with conventional wisdom, even on something as fundamental as aero tube design. Aero tubes are designed based on a series of flat 2D cross sections that connect together into a tube shape. But in the real world, the air flowing over a tube doesn’t follow a flat path, it follows an arc. So 3T built the Arcfoil tubes as a series of curved instead of flat Sqaero cross sections. These exactly mimic the arc of the actual airflow at several points along the tubes and substantially lower the drag (the arc of the downtube logo pays hommage to exactly the airflow and cross section arc there).
The Sqaero airfoil sections of the seatube arc for a different reason, to perfectly cover the rear tire and reduce the turbulence. Seatpost, headtube, even the seatpost clamp and dropouts are optimized aerodynamically in sometimes unexpected ways based on our real world analysis (for example you may wonder why the area behind the lower headset isn’t faired; the answer is simple, because the air doesn’t flow horizontally there but spins off the front wheel almost vertically, so a horizontal fairing shape is counterproductive as it blocks the upward airflow).
FUNDI AERO FORK
MINIMALIST CROWN: Instead of a bulky, unaero crown, 3T minimizes its size. This improves the crown’s aerodynamics and moves the front wheel closer to the downtube, creating a perfect transition for the airflow.
SQAERO FORK LEGS: The Sqaero fork airfoil only has a small truncation, perfect to guide the airflow around the front wheel and boost fork stiffness. Different left & right profiles are used to counteract braking forces.
INTEGRATED ADAPTOR: The Fundi supports flat mount disc brakes with 140/160mm rotors. The disc adaptor to switch between 140 and 160 is completely integrated into the left fork leg shape.
KINKED LEG: The Fundi connects all the relevant points (axle, brake mount, crown) the most direct way possible, achieving a low weight and a minimal frontal area with visually striking design.
DESIGN IS IN THE DETAILS
MIND THE GAP: A smooth transition of the airflow from front wheel to downtube and from seattube to rear wheel is crucial to lowering drag. The STRADA minimizes these gaps while respecting the UCI rules.
AEROFLEX: Bike frames are inherently stiff vertically, and the right tires offer much more comfort than a frame ever can. But we eke out a few last percent with our extremely thin (=aero & comfortable) seatstays.
DISC BRAKE ONLY: 3T didn't want to compromise weight, stiffness and aerodynamics by combining disc & rim brake versions in one frame platform, so everything on the STRADA is fully optimized for flatmount disc brakes only.
HIDE-RATION: The STRADA downtube is shaped to hide the water bottles from the airflow. The fastest set-up is one bottle low on the downtube, the “team-leader” configuration. Second-fastest set-up is with two bottles.
sizechart: SIZE S M L XL FORK AXLE-CROWN 355 355 355 355 HEADTUBE ANGLE 71,2 73 73,5 73,5 SEATTUBE ANGLE 72,5 72,5 72,5 72,5 TOPTUBE LENGTH 529 550 571 592 SEATTUBE LENGTH 390 420 465 485 HEADTUBE LENGTH 119 143 172 202 BB DROP 71 71 71 71 STACK 507 536 565 594 REACH 369 381 393 405 FRONT CENTER 567 573 589 609 REAR CENTER 405 405 405 405 FORK RAKE 43 43 43 43 Specs:
3T Strada Frameset
FRAME SIZES S - M - L - XL FORK 3T FUNDI TEAM 12mm thru axle BB BB386EVO HEADSET 1 1/4 - 1 1/8 SEATPOST 3T Charlie Sqaero Strada (CHARLIE EXPLORO is NOT compatible with the STRADA frame) AXLES 3T custom: 142x12 rear (Syntace X-12), 100x12 front BRAKES Flatmount 140/160mm CABLE ROUTING Internal via interchangeable FlipTop covers for 1x11 machanical, Di2, eTap FRAME WEIGHT 970g +/- 3% (M size) TIRE CLEARANCE Effective width: 28mm, Wheel radius: 344mm (wheel radius) COLOR Red (TEAM frame) INCLUDED IN THE BOX Frame, fork, headset, seatpost, seatpost internal clamp, front and rear thru axle, 2 rear derailleur hangers, noise-cancelling foam sleeve for rear derailleur housing and brake hose