For the PF30A-83 frames, the BB shell is 5mm wider on the drive side and +10mm wider on the non-drive side.Ĭannondale Asymmetric Integration (Ai) found on Scalpel-Si and F-Si System frames. Specialized carbon road frames with 61mm wide shells for use with Specialized FACT cranks.Īsymetrical BB shell is +5mm wider on the non-drive side (PF30A). Also used by 3T.īB shell is 11mm wider on the non-drive side.
![Colnago Serial Number Chart Colnago Serial Number Chart](https://dbyvw4eroffpi.cloudfront.net/size-guides/Colnago/Colnago-Master-Bicycle-size-guide.jpg)
![Colnago Serial Number Chart Colnago Serial Number Chart](https://live.staticflickr.com/7430/11467056163_f9f78388e0_c.jpg)
Then measure both the inner diameter and width of your frame's bottom bracket shell. To accurately determine the bottom bracket standard in your frame, it is best that you remove your crankset, and any installed bottom bracket cups or bearings. Finding the correct bottom bracket for your frame can be challenging.