Bikone DCTech PF46 Internal Oversized for BB30 is a high-precision bottom bracket designed for bicycle frames with a worn out bottom bracket shell. Over time, press-fit models can expand due to wear, causing improper fit, annoying noises, and an uncomfortable pedaling experience Our innovative solution extends the lifespan of your bike. This model features cups that are 0.1 mm larger than standard bottom brackets, ensuring a perfect fit once again. With Dual Cup Technology (DC Tech) and our top quality bearings, you will experience the smoothest of rides. Restore your bike’s performance and keep riding with confidence! See the assembly instructions and spacer list here For a correct compatibility, mountain cranks should be always mounted on mountain frames and road cranks on road frames.