The Surly Cassette Track Cogs are designed to spin onto standard ISO-threaded (1.375" x 24tpi) hubs, so they will work with most English, Italian and Japanese hubs, including the Surly New track hubs. The thread base is 7.4mm wide for maximum thread engagement while maintaining enough room for a track lockring to thread on. Like our cassette-splined cogs, these are made from machined, heat-treated and chrome plated SCM415 CroMoly steel, so they are tough and long lasting.
• Machined from SCM415 CroMoly steel
• 1.375" x 24tpi
• Thread Base is 7.4mm Wide
• 4.35mm thick