- by Christopher Jones
- Published: 19 May 2009
3D cranks use a third generation of DTT technology in the left crank clamping system. Despite the fact that these cranks have a more conventional assembly method (clamped crankarm on the axle), the clamping system of this crank used DTT bolts which guarantee a reduction of stress rizers in the clamping area. This allows the user to securely clamp the crank together using a low torque setting, meaning even less stress in assembly and weight savings.
This weight saving is possible because of the more uniform diffusion of clamping stresses inside the bolts themself, and between the bolt and the surrounding material, allowing ROTOR to reduce excess reinforcing material, saving grams without sacrificing rigidity, reliability or safety.
Utilizing a special manufacturing process, named the "Trinity Drilling System," an extruded aluminum bar is intricately CNC machined with three drilled holes through the length of the crank. The result is a unique triple hollow crank arm that enables ROTOR’s engineers to remove the excess aluminum in the core while still maintaining the structural strength of the crank. With this new system ROTOR has significantly improved the Hollowminum technology they developed for their Agilis Evo cranks.
"The 3D cranks are the first cranks to have been designed with the input of a pro cycling team together with our ROTOR engineers," said Ignacio Estell?s, President ROTOR Bike Components. "Drawing on a wealth of technical experience, this innovative product was developed collaboratively with Cerv?lo’s engineers, TestTeam riders and the TestTeam’s mechanic staff. We are passionate about supporting the riders, because they need these products in order to do their job well."