Schlumpf bearing failure

While changing a spoke, I noticed that the outer part of the splined bearing of my schlumpf hub broke into several pieces.

It’s an old schlumpf hub (M0134), which I bought in May 2016 from an excellent French unicyclist:

(There is a little sentimental side, this video was released in the first weeks when I started unicycling)

I noticed that there were problems with the bearings, and all 9 bearings were changed in June 2016.

Since 2018, I have occasionally heard strange noises coming from the hub, sometimes for several sessions in a row, and then suddenly no noise for months. A week ago I heard this kind of noise again, I stopped, looked at the hub, saw nothing and it passed.

On Monday, a spoke broke, and yesterday evening when I was replacing it I noticed that the outer part of the splined outer bearing was broken into pieces, some pieces were already gone, others were still in place.

I think this problem is not recent, but maybe I’m wrong… I sometimes have some difficulty shifting gears (with a delay of several pedal turns…), but I have trouble seeing how this could be related.

I was training to attemp for the hour record in a few weeks, I admit that it could cool me down a bit…

I easily realise that :

  • external particles could get into the bearing and damage the balls
  • the bearing grease leaks easily, which could accelerate the wear of the bearings and contaminate the brake disc and pads.

But I don’t know if this problem can generate other consequences (high speed crashes…).

If there are any experts who have an informed opinion on the subject, I’d be interested. In any case, I will have to contact Florian Schlumpf again at some point, it’s been too long since I’ve had any problems.


If you are unlucky and the bearing seizes, yes, that could lead to a high speed crash, I don’t think it’s likely, but if the cage breaks it could happen. It also probably doesn’t do it’s job of supporting the axle very well anymore, which means that force may end up in different places (like the gears and other bearings). I’d have to look at a drawing of the hub to see where that force ends up, but it might lead to other parts breaking or wearing quicker - I wouldn’t ride it in this condition.

It’s probably a standard bearing, and seems to be in an accessible place. If sending it in to Schlumpf takes too long for your timeline for the hour record, maybe a local machine shop can remove the old bearing and press a new one in.

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Thanks for your response. I got a similar answer from @jaco_flans. I needed that to hold me back.

I stopped riding it, and convinced a friend to lend me his wheel (I had already managed to convince her to buy the braus carbon rim and the BF before).

It’s now clear that my hub is damaged, the shifting is much better with my friend’s hub.

I sent an email to Florian Schlump 2 weeks ago but have not yet received a reply.