Bikemonger says... "This is what you will find on our own bikes. The wide foot print means they don't cut into your cassette body. Great quality, last real well, look nice especially 17t and larger as they are drilled, and the guys at Surly are good folk too".
Surly says.... Our cassette cogs are designed first and foremost for singlespeeding, but being that we’re Surly, we bumped up the versatility a bit. At the base, the cogs are 4.35mm wide, which allows you to stack a few of them up for a simplified multi-speed drivetrain. Use a 9-speed derailleur if you do that.
Machined from SCM415 Chromoly steel
Heat-treated and chrome-plated
Compatible with 6- to 9-speed 3/32" chains
Available in 13t–22t