▎ 摘　　要

NOVELTY - A high-intensity bicycle speed change gear comprises 75-80 pts. wt. resin, 40-45 pts. wt. polyamide resin, 22-24 pts. wt. polyurethane resin, 11-13 pts. wt. silicone resin, 7-9 pts. wt. polyvinyl formal, 2.6-2.8 pts. wt. calcium carbonate, 1.2-1.4 pts. wt. sodium selenite, and 0.5-0.7 pt. wt. graphene. USE - High-intensity bicycle speed change gear. ADVANTAGE - The speed change gear has improved compactness, durability, heat resistance, film forming property and fluidity, promotes smooth gear surface, avoids post treatment, and saves treatment process. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of speed change gear comprising mixing resin and polyamide resin, heating to 400-500 degrees C, adding polyurethane resin and silicone resin, stirring, and melting; adding polyvinyl formal and heat-preserving for 20-30 minutes at 300-400 degrees C; adding remaining raw materials, melting at 600-700 degrees C for 40-50 minutes, and stirring 34-36 revolutions/minute; and molding, naturally cooling to 300-400 degrees C for 25-30 minutes, freezing at - 33 degrees C to - 31 degrees C for 8-10 hours, and demolding.