Leaky Shlumpf Hub

Just bought a shlumpf hub from a user here. I just cleaned it up a bit and put some new chain oil in it. I woke up this morning and there was oil leaking from the hub to a point there was a puddle below the unicycle.
I do not know much about the shlumpf product other than what I have read on the KH manuals and shlumpf website. I anyone knows what would causes this and if/how I could fix it that would be great.

Probably not a problem with the hub, they’re not totally sealed and will leak some, more in higher temperatures and/or with low viscosity oil. There are a few Schlumpf hub discussion threads you might check out:
Schlumpf hubs: general discussion.
Schlumpf hub setup discussion thread
Schlumpf hub servicing
Schlumpf oil

You can also get more of the grease that Schlumpf uses.

Not a Schlumpf owner, but just using simple logic… this could be a sign that you’ve filled the gearbox beyond capacity.

As unishark said, it is designed to do this. Use a higher viscosity oil or grease, if you don’t want it to happen.


You probably over-filled it. As Florian has said, they will leak to some extent, but if there’s just too much lube in the hub, it will come out a lot more then usual, which should be gradual and minimal.

cool thanks I did not know they could be overfilled honestly. well hopefully no damage done and Ive just got a greasy mess to deal with for a few days.


I hear bacon grease is a prime candidate… hahahahaha. :stuck_out_tongue:

Centrifugal and gravitational force will pull regular oil off the gears and out to the hub body, where it won’t do any good. If your hub is truly overfilled with oil, and it eventually stops leaking, does that mean it now contains the proper amount of lubrication… or none?!! :astonished: Oil and grease are different.

Some greases are formulated to make them stick to the surfaces they lubricate.
Schlumpf Innovations chose a grease with these properties. Even still, I bet every Schlumpf hub owner wonders how much grease is actually in their hub and when to add more. It’s a bit of black magic. The easiest unknown to remove from the equation is the quality and properties of the grease you’re using.

I’ve tried to create a cheap easy way for Schlumpf hub owners to purchase the right grease. I encourage every Schlumpf hub owner to take advantage of it.