Eagle crank claims another victim

jimjimjimmy said

RAMM I think a good balance job really adds longevity to a high hp cast crank build . what you say about stiffness of the cast crank is very interesting maybe that's why they snap when they reach their limit they don't flex to absorb the stress or am I over thinking this

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Stiffness and brittleness USUALLY go together but it is really dependent on the materials. What is wanted in this use is a materials property called 'toughness' (Yes, that is real materials term...). The materials used in a forging are quite different than a casting; the forged crank material HAS to be able to withstand a lot of distortion, because the forging process involves literally 'pushing' the material around in some areas to get it into the final shape and it gets a crapload of force and movement going on within portions of the original casting. So the forged crank materials would seem to NEED to possess better toughness to even survive the forging process alone.