A Hambini viewer recently enquired about a bottom bracket for his Cannondale TopStone Gravel bike. This bike uses a BB30A83 bottom bracket. A design which is highly unusual, extremely rare and unique to Cannondale.
From the frame centerline, the driveside and non drive side apertures have an asymmetrical offset – hence the “A” in BB30A83. There is not much room to work with on the non drive side. Additionally, the user requested a necked design to give him clearance for his internal cables.
The final design is shown below
Following customer demand, this bottom bracket has become a production item. It is available here