The Renthal 121U-420-47GBSI UltraLight rear sprocket is a CNC-machined aluminum replacement designed for select Yamaha YZ65 applications. It features a 420 chain size and 47-tooth configuration, with a silver finish and grooved design.
Manufactured from 7075 T6 aluminum, this rear sprocket is engineered for reduced weight compared with steel while maintaining strength for powersports use. Renthal uses computer engineering and testing to support precise fitment, concentricity, load dispersion, and efficient power transfer. Tooth profiling is designed to help provide consistent chain engagement.
This Renthal rear sprocket fits the 2018, 2019, 2020, and 2021 Yamaha YZ65. The manufacturer part number is 121U-420-47GBSI, and the vendor part number is 121U-420-47GBSI. Verify the model year and existing chain specification before installation.
Features:
- Brand: Renthal
- Product type: UltraLight rear chainwheel
- Material: CNC-machined 7075 T6 aluminum
- Chain size: 420
- Tooth count: 47
- Finish: Silver
- Design: Rear grooved sprocket
- Fitment: 2018 Yamaha YZ65
- Fitment: 2019 Yamaha YZ65
- Fitment: 2020 Yamaha YZ65
- Fitment: 2021 Yamaha YZ65
- Manufacturer part number: 121U-420-47GBSI
- Vendor part number: 121U-420-47GBSI
Air Freight Prohibited: false
Not Carb Approved: false
Ltl Freight Required: false
Prop 65: Unknown
Part Type: powersports
Epa: N/A
Carb Acknowledgement Required: false
Clearance Item: t
Regular Stock: false
Units Per Sku: 1
Fitment:
2018 Yamaha YZ65 Base
2019 Yamaha YZ65 Base
2020 Yamaha YZ65 Base
2021 Yamaha YZ65 Base