NEW Surly Cogs Track Cog Surly Track Cog 1/8'' X 17t Silver rear-derailleur-mount-type_shimano-rear-direct-mount The Shimano GRX ST-RX815 11-speed

The Shimano GRX ST-RX815 11-speed Di2 shift/brake lever integrates electronic shifting with improved grip and confidence on chippy surfaces and descents

Efficient SPD step-in design on one side with a flat platform on the other

Shaft Type: Threaded

spoke:14/15/14g

1” tires

NEW Surly Cogs Track Cog Surly Track Cog 1/8'' X 17t Silver rear-derailleur-mount-type_shimano-rear-direct-mount The Shimano GRX ST-RX815 11-speedSurly track cogs are threaded the same as a BMX freewheel (1. 375 x 24 tpi right hand threads). This means that they will fit on single speed rear hubs, as well as BMX freewheel hubs, but this application is not recommended. Track cogs are meant to work on track hubs only. 415 hardened chromoly steel 1. 375" x 24 tpi Photo for color and material reference only Tooth Count: 17