CAPACITY BOOSTER 12 SPEED

CAPACITY BOOSTER (Big Pulley Set) specially designed to work with SHIMANO 12-SPEED drivetrain.

Just swapping out Shimano original pulleys to CAPACITY BOOSTER increases rear derailleur capacity and prevents chain slack when crosschained in small /small when CY4-SHC 33T or 32T is used*.
*For 34T and 36T, either Shimano original pulleys or CAPACITY BOOSTER can be used.
*For 32T and 33T, the use of CAPACITY BOOSTER is required.

CAPACITY BOOSTER perfectly fits Shimano 12-speed drivetrain, work with the standard cage on Shimano derailleur and boost derailleur capacity and shifting performance.
①Swing Eccentric Mechanism
As the axle is fixed eccentrically, the pulley resonates with the motion of the rear derailleur and adjusts its position to cassette cogs automatically. So, shifting is just as accurate as it is with the original pulley.
②Rotational resistance
Oversized pulleys and ceramic bearing reduce rotational resistance.
③Friction resistance (S3 coating)
S3 combines high hardness with super low friction coefficient less than half that of the titanium coating. So, the chain resistance could be reduced to the minimum.

Size : Guide pulley 12T & Tension pulley 16T
Material : CNC aluminum alloy (S3 coated)
Bearing : Ceramic (sealed)
*Set includes 2 pulleys (guide & tension)
*Shimano rear derailleur is not included.

Compatibility
CAPACITY BOOSTER-12SDA for SHIMANO RD-R9250 (DURA-ACE)
CAPACITY BOOSTER-12SUL/105 for SHIMANO RD-R8150 (ULTEGRA) & RD-R7150/RD-R7100 (105)
Chain : SHIMANO 12 speed
*Please select CB12SDA or CB12SUL/105 depending on your rear derailleur. These 2 versions are not interchangeable.