Vortex 251AZK-45 Black 45-Tooth 520-Pitch Aluminum Rear Sprocket

The Vortex 251AZK-45 is a 45-tooth, 520-pitch rear sprocket machined from lightweight CAT5 aluminum alloy. Engineered for performance motorcycle applications, this sprocket is 100% CNC manufactured in the USA to Vortex's exacting tolerances, delivering consistent quality and exceptional durability on the street or track.

Vortex uses a specially formulated aluminum alloy developed to their own specifications, striking the ideal balance between reduced unsprung weight and long-lasting wear resistance. The patented Vortex tooth profile is unique in the industry, engineered to extend sprocket longevity and optimize chain engagement throughout the sprocket's service life.

Key Features:

• 45 teeth — rear sprocket position
• 520 pitch — compatible with 520-pitch chain (note: many applications require a 520 conversion)
• CAT5 aluminum construction — lightweight without sacrificing strength
• 100% CNC machined in the USA — precise, consistent fitment
• Specially formulated alloy per Vortex proprietary specifications
• Patented tooth design — unique geometry for extended service life
• Black anodized finish with contrasting silver machine cuts
• Available in multiple colors to match your bike's style

The Vortex 251AZK-45 rear sprocket is an excellent upgrade for riders looking to reduce rotating mass and fine-tune their gearing ratio for both track days and street performance riding.