JT Sprockets 420 Steel Rear Sprocket, 37T (JTR1213.37)

A C49 high-carbon steel rear sprocket — JT's bread-and-butter replacement that swaps in like the OEM part for hundreds of street and sport fitments.

• C49 high-carbon steel, induction-hardened on the tooth crowns for wear life that outlasts cheap stamped aluminum on the street.
• CNC-machined to OEM bolt pattern and profile so it lines up to your hub without modification.
• Same fitment universe as JT's zinc-black (ZBK) and self-cleaning (SC) variants on this base.
• Built by JT Sprockets — the world's largest sprocket manufacturer, with sprocket production for major OE bike brands.
• Sized to OEM gearing with shorter/taller tooth-count options available on select fitments.

Intended use: street, sport, sport-touring, adventure.