LIGHTNESS, RIGIDITY, SIMPLIFIED ASSEMBLY AND MAINTENANCE:ULTRA-TORQUE™.
THIS IS CAMPAGNOLO'S ANSWER IN THE INTEGRATED CRANKSET SECTOR.
AFTER MORE THAN 10 YEARS SINCE ITS INTRODUCTION THE ULTRA-TORQUE™ SYSTEM, IT IS STILL CONSIDERED, THE BEST PERFORMING CRANK-SET SPINDLE IN TERMS OF STIFFNESS, LOW WEIGHT AND EFFICIENCY OF POWER TRANSMISSION.
Campagnolo found a way to permanently conjoin the semi-axles of the bottom bracket to the respective crankset arms. This redesign made it possible to considerably reduce the lateral dimensions at the axle level and prevent annoying contact with the ankles when turning the pedals.
Assembly is simplistic: one single oversize bolt is enough to integrate the two semi-axles. With regard to torque
transmission efficiency, this system is equally as effective as a single piece axle.
Furthermore, despite the narrow side profile, we have been able to position the bearings outside the bottom bracket shell, resulting in greater axle rigidity from the increased axle diameter. This breakthrough was obtained by using an ingenious mechanical system derived from many years' motoring experience in the rotation axle and engine shaft coupling sector: the Hirth joint.
In short , this is a joint with self-centring and self-aligning frontal teeth located in the middle of the bottom-bracket
axle where the ends of the semi-axles, integrated with the crankset arms, come into contact.