My threads from the crankset were gone, had to cut all crankarm with iron cutter in order to be able to extract the crank arm. But before that, I gave some hammer strikes to it trying to get it out. Now I've ordered a new crankset, but I cannot find any compatible BB with this one in the photo, size: 73 x 124.5mm Till I find one, I want to reuse this, but I am not sure about the little play it has in the directions pointed by arrows. When mounted, I don't think it has any play, or maybe now it has (because of the hammer hits).

So, what could go wrong or more exactly, how much time can I ride anymore with this BB. Play is not big, just a little. Holidays are coming and I plan to ride my bike for next week in the snow so more pressure will be put on the BB.

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  • 1
    Significant overlap with bicycles.stackexchange.com/questions/47207/…
    – DWGKNZ
    Dec 22, 2021 at 15:00
  • That's how I got here, found that answer on google. But it doesn't overlap "so much" because my play is in different directions (I think).
    – iBike9595
    Dec 22, 2021 at 15:06
  • 2
    As with any highly loaded bearing: Play in any direction is never good!
    – Carel
    Dec 22, 2021 at 15:39
  • Thank Carel, will keep going on my own risk. I will upload a video with the play later, if it's possible here, or streamable maybe
    – iBike9595
    Dec 22, 2021 at 15:41

2 Answers 2


From a safety POV, there is no problem until the BB is really really bad - not talking 'a little bit of play'. You can pretty much ride a stuffed BB as long as you can tolerate it.

As the bearing deteriorate, you will notice movement in the pedals, possibly grinding and generally the bike will feel horrible to ride and possible compromise shifting of the front gears. Its one on those things that sneaks up on many riders, its not till they replace the BB that they realise how bad the old one really was.

At the very extreme amount of wear, the chain retention on the chain rings will become compromised and you could start to suffer chain drops - but by then the slop will be obvious to the most mechanically challenged rider.

  • 1
    I think this is right. Any failure of the BB should presumably be contained to the BB.
    – Weiwen Ng
    Dec 23, 2021 at 0:58
  • 1
    yep - the worst that can happen is it fails completely when you're out on a ride, and have to walk home. Happened to me when a cup split in two, so I was able to scooter the rest of the trip.
    – Criggie
    Dec 23, 2021 at 4:33
  • Maybe in the very worst case the bottom bracket could suddenly lock up right in the middle of pedaling.
    – Michael
    Dec 23, 2021 at 9:54
  • @Michael I've never heard of that happening. When I worked as a mechanic I saw some pretty horrible examples of worn bottom brackets, to the extent that sometimes the threads in the frame were damaged, but never any suggestion of seizing.
    – bertie
    Dec 24, 2021 at 18:30

Bottom brackets are not crazy expensive. Just play it safe, and replace it.

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