Convert One Piece Crank To Three Piece Crankset/Bottom Bracket

Posted by on in Bottom Brackets, Cranksets


I show how to replace 1 piece (“Ashtabula”) cranks with modern 3 piece cranks using an adapter. These one piece cranks were mainly found on older American made bikes like Schwinn, Huffy, Ross, etc, BMX bikes, and childrens bikes. The bottom bracket shell is larger and the cups are pressed in. But with adapters, you can install a variety of English threaded bottom brackets like square taper sealed cartridge, Octalink, GXP, Hollowtech, or whatever. I also show how to deal with issues like ridges/obstacles inside the BB shell, and also dealing with a 65mm versus a 68mm BB shell. The benefits are a lighter crankset and also the ability to change to different chainrings. It’s a cool upgrade to a vintage bicycle.

The adapter I used is called American To Euro BMX Adapter and was made by Truvativ. Here it is at Amazon:

Here is a similar American To Euro adapter made by Black Ops:

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