Rotational resistance

Rotational resistance

Our best bearing system ever

When talking about bearing performance, strength and durability are just as important as the smoothness of rotation. While ensuring sealing performance (waterproof performance), we thoroughly pursued the reduction of rotational resistance, which is a contradictory factor.
By repeating tests under various conditions, such as the shape and hardness of the seal and the viscosity and amount of grease, we have developed one of the best bearing systems in our history, which reduces rotational resistance by 64% compared to that of conventional models.

Best bearing system ever

DURA-ACE’s uncompromising performance

The bearing rotation performance of the ULTEGRA series is at a sufficiently high level. However, we have pursued even higher performance for the DURA-ACE series. To thoroughly reduce rotational resistance for the DURA-ACE series, we have selected stainless steel balls with high sphericity and applied a film-type super finish to the ball race, carefully choosing the best polishing condition.