Originally Posted by
bulgie
One broke at the pedal hole, the other further up toward the BB spindle but not all the way up.
Thanks.
I've seen pedal-eye failures and cracks at the spindle end - on TA cranks those sections are quite small.
Cracks develop from a failure of some combination of four things:
Material
Design
Finish
Use
Mention above of "soft" TA cranks is intruiging, but I suspect the small sections are more likely responsible.
Is the particlar aluminium alloy known?
Of all the cotterless cranks the least crack-prone may be the Nervar 5-pin.