Lock ring and O-ring kit ensures secure attachment of chainring and spider to motor drive pinion for reliable performance
Substantially tougher material than plastic nuts increases longevity and resistance to wear
Designed specifically for Bosch Performance CX Gen 4 drive units for precise compatibility
Easy installation and removal for convenient maintenance and repairs
Summarized by Shop
This is the Lock Ring and O-ring kit to hold the front chainring and/or spider onto the motor drive pinion on the Bosch Gen 4 Drive Unit (BDU4XX)
Substantially tougher than the plastic nuts, although be careful not to cross thread the nut on the drive unit assembly.
PLEASE NOTE: If you have a Bosch Classic +, Active Plus or Performance
Compatible Bike Type
Electric
Color
Black
Pattern
Solid
Kit Contents
Lock ring and O-ring
Material
Not specified
Model Compatibility
Bosch Performance CX Gen 4 drive unit BDU4XX
Summarized by Shop
4.7
23 ratings
5
4
3
2
1
Amazing service
Everything was perfect! The item arrived right on time, and the price was very reasonable. It is a genuine, original part that fits the Bosch Performance CX (Gen4) motor perfectly—just like the factory one. Reliable seller, highly recommended! Thank you!
A
Andras · May 27, 2026
Gen 4 lock n o ring
Easy to use site and delivered on time , but had to order the lock ring aswell as the o ring , not overly expensive but the option of further o rings would have been a nice touch . So inevitably I will still shop around and not bookmark e bike shop as my main go too