It has become fashionable to say that bikes have gotten as aero as possible. However, the Factor HANZŌ proves otherwise. When designing it, we decided to capitalize on the revised UCI rules with the goal of making the fastest purpose-built time trial bike in the world. Focusing on each part of the bike, both individually and as a working whole, we have pushed each directive from the UCI to the absolute limit in innovative ways. Other manufacturers who do not own their own factories cannot approximate this level of control in the process which makes such precision possible. This means that we have been able to make the HANZŌ faster and more aero efficient than the SLiCK and faster even than non-UCI legal time trial and triathlon frame designs.
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SHARP LEADING EDGE
The front end of the frame defines the level of aerodynamic efficiency. A change in UCI rules now allows for a minimum cross section on all tubes to be as small as 1cm — down from the previous minimum of 2.5cm. With this new rule, we can reduce the frontal area by as much as 60%. But it’s not as easy as it sounds since the front end inevitably has large functional constraints such as headset bearings and cable routing that get in the way. By focusing on area reduction, we have succeeded in reducing the net aerodynamic drag of the area exposed to undisturbed airflow. Simultaneously selecting the perfect airfoils while taking into account the angle of attack remains the key to ensuring the bike performs optimally during real world racing conditions.
AERODYNAMICS BASED ON FLOW CONDITIONS
Designing the HANZŌ to deal with the various flow regimes that a rider will face means considering multiple separate conditions in the design process: the undisturbed flow aft of the rider’s body, the spinning reaction air from the wheels, and the turbulent flow coming off the rider’s legs and calves. Having the thinnest possible frontal frame thickness and allowing for wide frame clearance from the spinning wheels aids the aerodynamics. Meanwhile, radical seatstays and drop out shapes work as inline aerodynamic flow conditioners to corral the vortexes emerging from the rider’s rotating legs and feet.
A TRUE AIRFOIL IS KEY
Having a super thin front end, where the shape of the fork combines with the frame shape, creates a true airfoil to optimize the lowest possible drag by facilitating full laminar attachment at low yaw angles. This incredibly aero design with a single piece fork, external steerer, combined with the mono-riser also enhances the structural efficiency since it’s a single part solution that would normally be dozens of items bolted and stacked together. Having the ability to mold the entire assembly in a single piece provides exceptional stiffness and weight improvements over systems that have extensive overlapping material in either bond joints or slip joints. Every part on the bike has been shaped carefully, with particular attention being paid to the transitions between tube shapes to give the best possible performance at low and high yaw.
A STIFF, RESPONSIVE RIDE
Aero isn’t everything. The HANZŌ is so much more than one of the world’s fastest time trial bikes. It’s incredibly stiff as well, capable of translating each pedal stroke into speed. The one piece fork and head tube leading up to the mono riser ensure the front end is rigid and immediately responds to the rider’s input. As we move further back on the bike the stiffness of the design takes center stage. The down tube has an aerodynamic function, particularly in how well it integrates an aero water bottle, but it also offers a sturdy joining point for the super rigid bottom bracket. This design pushes the UCI rules right to the limit for the ultimate in aero performance while still being able to transfer power efficiently.
PENALTY-FREE PAD STACK
Having the ability to get the fit right for each rider is equally important as making the frame as aero as possible. The HANZŌ’s has been designed to work well with multiple popular manufacturers’ aero extension bars. We’ve provided popular component manufacturers like AeroCoach and WattShop with the CAD profiles for the mast allowing a variety of solutions to be available to riders above and beyond our own Black Inc TT extensions.
SLICING THE TIMES
Whether the race is WorldTour or a local Wednesday evening time trial series, every competitive cyclist wants equipment that enhances every performance. The HANZŌ time trial bike pushes right up to the limits of UCI design regulations to make it among the fastest UCI-approved TT bikes in the world.
REDUCED PROJECTED AREA
Whittling down the front end so dramatically resulting in the narrowest possible head tube reduces the projected area. Projected area is equivalent to the area obscured by the object as it passes in its direction of travel. Reducing the HANZŌ’s projected area by 31% compared to the SLiCK effectively decreases the drag at all velocities.
AERODYNAMIC WHEEL-FRAME INTERACTION
The rotating wheels and tires represent a unique challenge. The fully reversing flow comes off of the spinning tire and interferes with the frame and fork causing drag. With the HANZŌ we carefully moved the airfoil sections well clear of the rotating tire, preventing the interaction effect and allowing both sections to perform optimally. This approach accommodates up to 28mm tires. Having greater clearance around the tires reduces the effect a tire’s shape has on the airflow through the fork and frame. The one piece fork’s wide stance not only works with the rotating front wheel to improve efficiency, but at the rear, the seat stays are as wide as UCI regulations allow in order to smooth the airflow between rear wheel and frame, as well as airflow off the rider’s calves.
INTEGRATION AND COMPATIBILITY
As the first bike to maximize the potential of the UCI’s revised design rules, the HANZŌ uses never before applied airfoil sections for the full 16cm of length allowed by the alignment of the head tube and down tube boxes. The design also integrates the basebar and frame top tube into an aero section, with seamless blends between those shapes to ensure minimal airflow detachment. Cable and brake line integration also plays a key role to ensure the HANZŌ shows the most aero face to the wind as possible.