Yamaha Gear 1 (1.5/1 Ratio) 6T5-45881-00-00. Overview. The Yamaha Gear 1 (1.5/1 Ratio) 6T5-45881-00-00 is a genuine original equipment manufacturer component designed to deliver precise motion transfer and optimized mechanical performance within your Yamaha system. Featuring a 1.5:1 ratio, this gear helps balance torque and speed, ensuring efficient and reliable operation.. Engineered to Yamaha's exact specifications, this gear provides a precise fit and dependable durability. It is an ideal rep