Cracked Aluminum Sturmey-Archer Hub Shell

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Sturmey-Archer hub shell with flange cracks through spoke holes. From http://www.rideyourbike.com/sturmeyarcherIGH.shtml as of 2011/05.

Flange failure are more common with radial or low-cross lacing. However, the deformation of the spoke holes suggests this hub was laced nearly tangent. Given the hub's age (probably over 50 years old), it is possible it was relaced, and relacing in a different pattern sometimes causes flange failures. The cracks are unusual that they extend inboard of the spoke holes. Flange cracks related to spoking often pull out the flange material without cracking inboard of the hole. The crack pattern thus suggests the failure was caused by stresses from the inboard pressed-in cup.

Usage history of the hub is unknown.