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