Broken crankset spindle = man down

13»

Comments

  • buckmulligan
    buckmulligan Posts: 1,031
    Sure, it's definitely unusual for the bearings to come out Shimano HTII cups under normal circumstances, but I think the mode of failure is to blame for that here. The spindle snapping under load is going to be like prising the bearings out with a massive screwdriver. They're a snug fit and they have to be to not suffer from the litany of creaks and groans that nearly every other modern BB format suffers from; I doubt it's 'fused' here it's just been ripped out of the cup by the action of the failure.
  • ugo.santalucia
    ugo.santalucia Posts: 28,317
    good point
    left the forum March 2023
  • imafatman
    imafatman Posts: 351
    As a larger rider who puts out quite a bit of power this thing worries me.

    Does anyone know what material the tubes are made out of with an Ultegra crank? Is it steel or something else?
  • ugo.santalucia
    ugo.santalucia Posts: 28,317
    steel
    left the forum March 2023
  • imafatman
    imafatman Posts: 351
    Not sure if I feel better or worse.... Steel in theory much more durable in terms of fatigue but to see it sheer off like that is concerning.

    Would be good to see what Shimano conclude.... but not expecting for that to be made public.
  • ugo.santalucia
    ugo.santalucia Posts: 28,317
    imafatman wrote:
    Not sure if I feel better or worse.... Steel in theory much more durable in terms of fatigue but to see it sheer off like that is concerning.

    Would be good to see what Shimano conclude.... but not expecting for that to be made public.

    Unlike in the case of Zipp exploding hubs, where it was clearly bad design, here I don't see anything wrong with the design of the axle. They are extremely rare events and I wouldn't worry too much to be honest.

    Nothing is infallible
    left the forum March 2023
  • paul_onabike
    paul_onabike Posts: 194
    BMC rider had his left crank come off towards the end of stage one of the Giro approx 3k out. He can be seen carrying it on Eurosport highlights. Looks as if it is shimano and broken in the same manner?
  • First.Aspect
    First.Aspect Posts: 17,212
    Paul Onabike wrote:
    BMC rider had his left crank come off towards the end of stage one of the Giro approx 3k out. He can be seen carrying it on Eurosport highlights. Looks as if it is shimano and broken in the same manner?
    He was in a crash.

Categories