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its a mate of a mate so dunno his exact words. seemed to be a bad aluminium alloy thats not the right temper (if tempered at all) so its not suitable for greater riding forces.
HK_Berlin-
I think it's the design that's shit. You actually have to be deliberately trying to get common aluminium alloy billet in anything but T6 or similar temper, and the mill pretty much has to be deliberately trying to fuck up T6 heat treat.
As Chiroshi suggests, all that drillium provides a wealth of stress raisers for crack initiation.
gbj_tester
Hardened? What material does your mate think the cranks are made out of? My guess would be that the manufacturer didn't do proper stress analysis, or if it was a manufacturing fault then it would most likely be a sharp edge on the machining, which anodising makes weaker, leading to a stress fracture.