Blackspire Sprocket-B Sprocket 17 Teeth DM Bosch - Black

Blackspire Designs is the largest manufacturer of performance-oriented bicycle accessories in North-America, so it's really no wonder that Blackspire products are popular worldwide.
Blackspire parts aren't exactly cheap, but there's a good reason for that.
These parts are not produced at the lowest possible costs, and Blackspire uses only the best materials of aircraft-grade quality - that's the highest quality.
Blackspire is dedicated to producing high-quality bicycle accessories for any cyclist, bicycle parts you can count on whether you're an amateur or professional rider.
From wheel sets to chain blades, from cranksets to handlebars.