7-speed bicycle sprocket set with 13-28 teeth (teeth: 13, 15, 17, 19, 21, 24, 28). The high speed shift positioning slot ensures even load distribution, delivering smooth and powerful operation, short shift transmission time, reduced noise, and effortless riding. Excellent craftsmanship - Made of high quality stainless steel, finely tempered and hardened. - Rustproof surface with galvanization treatment. - High hardness, wear resistance and durability; not easy to rust; long service life and fewer replacements. Unique design - The angle and height of the steel teeth on each part of the flywheel differ slightly, allowing the chain to engage and switch up and down faster and more precisely. - Different tooth shapes are a characteristic feature of this flywheel design, not a defect. Precision thread - The flywheel is machined with high-precision tools; threads are clear and firm. - High-precision threads ensure a solid connection with the bicycle hub, improving shifting feel and making rides easier. Use scenarios - Daily urban commuting on mixed terrains where reliable shifting matters. - Uphill or light mountain routes where smooth, confident gear changes help preserve momentum. - Bike maintenance or drivetrain upgrade projects to extend service life and reduce maintenance frequency.