that your derailleur clears your 40 or 42 tooth cog? Look no further. When using the GC 40 with a Shimano rear derailleur, a longer B-screw may be needed. A longer b-screw ...
The Kogel Bearings Kolossos Oversized Derailleur Cage unlocks ...
top-tier drivetrain efficiency by implementing ceramic bearing pulleys for silky smooth movement and sturdy CNC-machined alloy arms for stiff performance that will shift reliably with less flex.