With the new Ultegra RX derailleur, Shimano expands compatibility to mechanical road shifting and suggests there is a benefit in having a clutch rear derailleur with double front chain rings when ...

Shimano, however, has taken a different approach ... the shifters are powered by two CR1632 coin cell batteries. The rear ...

with everyone from Shimano (Di2) to Archer and others coming up with their own version. Some of these require replacing the existing derailleur, while others should allow for non-destructive ...