Bicycle Cranksets - Whats the Hirth Joint Used in the New Ultra-torque Campagnolo Crankset

In was in the early 1900's that the hirth joint or hirthNo need for external flanges or bushings thus less
coupling was born, from the tinkering of Hellmuth Hirth,rotational mass, greater pedal efficiency and smoother
the young son of a German engineer. He wasriding.
fascinated with developing new and emergingExternal bearings can now be mounted on the half
technologies for the maiden aircraft industry. Hellmuthspindles leaving the entire circumference of the bottom
developed the hirth coupling as a high strength lockingbracket shell available for a larger hollow spindle. This
joint used initially to connect two ends of a shaft, inlarger spindle makes the drivetrain more rigid.
gasoline engine crankshafts.The Campagnolo crank arms can be fused to each
It looks like a set of teeth milled on the end profile ofhalf axle, so no pinch bolts are necessary for crank
each half shaft. They mesh together in a self centeringattachment. This reduces the weight making the
and self aligning locking joint. The amazing engineeringultra-torque the lightest crankset in the industry.
of the Hirth coupling is that it offers such a highThe final benefit of using a hirth joint in the ultra torque
strength connection on such relatively small diametercrankset is that Campagnolo can promote themselves
shafts. It has since been used for reversing gears inas having THE most easily installed crankset in the
marine applications and cooling water pumps in almostindustry. With traditional tools the cups can be inserted
every sector including automotive, rail and nuclear.followed by the half axles and a 10mm bolt to hold it all
Thus it is not surprising that Campagnolo wasin place.
interested in using such a proven piece of technologyCertainly this particular Campagnolo component has
in their newest cranksets designs. It has a long historytaken technological sophistication to the limit offering
of testing for strength and reliability in the mostcycling enthusiast something to talk about. At these is
extreme environments from marine to nuclear energy.further information about Campagnolo's bicycle parts
Advantages of Using the Hirth Coupling in theinnovations including the scoop about their newest
Campagnolo Crankset Design:carbon fiber forming capabilities and new ceramic
The axle of the new Campagnolo Crankset can bebearing bottom brackets.
spliced in the middle of the bottom bracket shell