Double Servo rear derailleur with smooth, precise shifting performance and wide-range capability. The SHIMANO ACERA M3020-8 rear derailleur with Double Servo technology helps you ride challenging terrain with fewer interruptions.

Double Servo construction for smooth and precise shifting

Versatile performance and wide compatibility

Compatible with 7-speed and 8-speed rear cassettes/freewheels

Compatible chain: HG 8/7/6-speed

Top-Normal spring type: Double servo

Mount: Direct attachment (Conventional)

Long derailleur cage (SGS)

Cable adjuster

Max. front difference: 20T

Total capacity: 45T

Low sprocket Max.: 40T

Low sprocket Min.: 30T

Top sprocket Max.: 12T

Top sprocket Min.: 11T

Fluoric coated link bushings: 1

Pulley Teeth: 11T

Sunken type pulley bolt

Material: Aluminum/Steel

DOUBEL SERVO: SHIMANOs double servo-panta mechanism enables the rear derailleur to move in an optimum path. The guide pulley tracks the cogs closely while moving front to back, optimizing each shift. Perfect tracking contributes to the most accurate SIS shifting. Keeps rear derailleur guide pulley an optimum distance from each sprocket.