• Anyone ever managed to crack a decent forged crank arm? Fitted my lovely TA Zephyr cranks to a build, and on the NDS I didn’t even get close to 40Nm before it gave out around the bolt. How did I fuck up?

    May give Chicken a call but as I’m not the original owner can only assume any warranty would be moot, even if this would count for it.

  • How did I fuck up?

    You didn't, that's just where you'd expect a square taper crank to fail. If you take it apart, you'll probably be able to see the fatigue crack which has built up over a long time which reduced the intact cross section enough to allow a brittle fracture of the remainder as you pushed it up the taper. If you hadn't broken it now, it would have gone at the worst possible time while riding, so consider it a success🙂

  • Excellent way of looking at it - all teeth and bones intact is a win. It only went after I’d fitted and removed it once due to the wrong BB length, too, so considering myself lucky.

  • brittle fracture

    Was it though? There's a strange depression around the crack, almost as if it's necked in...

    Hard to imagine that's actually the case though; doesn't seem right at all. Just a nasty forging?

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