Sram 10 speed pc1051 chain with powerlock a chain is only as strong as its weakest link sram took this to heart when they designed their innovative new 10 speed powerchain featuring the powerlock connecting link the hollowpin construction provides smooth precise shifting and weight savings powerlock sram chain engineers developed powerlock as a tool free sure and consistent way to connect their 10 speed chains while pl does not require special tools for install the especially tight tol