Round-Teeth™ Technology

Round-Teeth™ Technology was developed by Kappstein, a German engineering company specializing in high-performance drivetrains.

Chain drivetrains are widely adopted for their mechanical efficiency, structural simplicity, and proven durability. Despite these advantages, conventional chain–sprocket engagement inherently involves relative motion between the chain link and the tooth flank. This sliding component contributes to friction, surface wear, and incremental energy loss.

Traditional sprocket design has largely evolved through empirical refinement. Emphasis is typically placed on tooth strength, durability, manufacturability, and secure chain retention. While these parameters are essential, the kinematics of chain engagement are rarely treated as a primary optimisation variable. Sliding contact is generally accepted as an intrinsic characteristic of the system.

Our work focuses precisely on this interface.

Through detailed analysis of chain articulation and tooth engagement geometry, we examine how individual chain links transition onto and off the sprocket under load. This methodology is explained further in Our Technology. It includes the relative angular motion of the chain joint, load transfer across the tooth profile, and the progression of contact points during rotation.

Based on this kinematic analysis, we develop tooth geometries that more closely correspond to the natural motion path of the chain. By aligning contact surfaces with the chain’s articulation trajectory, relative sliding at the interface is reduced.

The result is a shift in engagement behaviour — from predominantly sliding contact toward a more rolling-oriented interaction. This contributes to improved mechanical efficiency, smoother power transmission, and reduced wear over service life.

Round-Teeth™ Technology therefore represents an extension of conventional chain drive design methodology. Instead of relying primarily on empirical parameter adjustment, it applies contact kinematics as a central design principle in sprocket tooth development. This technology is implemented across Kappstein chainrings for Track, MTB, and Gravel bikes.