Schlumpf oil

My schlumpf hub, which I basically love, is a bit ornery. Specifically, it leaks oil (just like both of my cars – gotta love consistency). The symptoms are that the outside of the hub is quite oily, and after a few hundred miles of riding I start getting some distressing grinding noises from inside the hub which go away after I inject some oil with the syringe it came with.

But, the syringe is almost empty. Anybody know what type of oil is needed? And any thoughts on why I’m leaking oil, or what I might be able to do to prevent it?

I don’t know anything about schlumpf hubs but this is from UDC.


If you get no information from Florian or any of the other Schlumpf owners, this is what I would do: Cram as much of the most viscous stuff you can find into the hub. If you can load it with a grease gun, do it. I’m kind of surprised that Florian didn’t put a zerk fitting on his hubs. If not, you should easily be able to find something from SAE 80 to SAE 150 differential gear oil for cars and trucks or outdrive oil for boats. This stuff is slightly less viscous than honey and can be poured but not easily. The syringe would have to have a 0.1" ID hypodermic attachment or larger to get the stuff through it. If it can’t flow, it can’t leak.

I pack my hubs with light lithium grease. It doesn’t come out. I don’t think those hubs see the miles that a car sees and the idea of repacking with grease is a little silly.

I guess this is normal. At least my hub leaks oil too, although less than my only car, which has a serious problem… But I still have a couple of syringes left before I’ll have to look for new oil. So I don’t worry about it really. Florian told me that it’s okay if you’re running low on oil. According to him it shouldn’t cause much damage to the hub. So I just refill when I hear the hub internals grinding.

I don’t have a guni but I have stayed at a Holiday Inn Express.

Some equipment has a grease zerk but much care must be taken to avoid overpressurizing the seals or the bearings to avoid damage. Grease guns can develop extremely high pressure.

Differential oil is a good suggestion because it can flow where it is needed rather than being pushed out of the way. Gears only need to run in a puddle of oil rather than being immersed. An oil level past a center shaft has more tendency to leak. A differential has a fill port that is lower than the axle shaft.

If the old oil can be removed even partially, then the trash developed during break-in can be removed or reduced.

Do you hear it grinding if you get off the uni and just rotate the pedals by hand, or do you only hear it grinding when riding? I have yet to hear my gears grind, and I haven’t added any oil since my hub was returned earlier this year. My hub does leak a little in that I see some oil on the outside, but I think for the most part it seals it quite well.

Grind on, grind off

Even when I’m low on oil it doesn’t grind continuously, just quite frequently, so it’s a bit hard to tell if grind much when I spin it by hand. I would think so, since the grinding while riding happens even when applying very light pressure. It was really bad last summer and I didn’t think to add oil (and on a 121 mile ride I didn’t have oil, which is when it was getting bad) but now I add oil the instant I hear anything suspicious.

I do hear it grinding when I rotate the wheel by hand too. I think it might be the dirt that gets in between the parts of the hub and the frame. Because mine is mainly being used off road and in dirt…

What the heck is good bicycle oil? Chain oil? Does it even matter? I should probably not be worrying so much about exactly much, but I’m a stickler for following precise rules. Neurotic some would say.

I wonder if the grinding is indeed from the hub, or if it is coming from dirt in the frame or something as munirocks pointed out.

I injected 1 syringe of oil when I got my hub back …I think in December, or maybe it was Feb?? I have about 650-700 miles on the geared 36er and I havent heard any grinding with my hub. I haven’t used it offroad for the most part.

Email Florian and ask what oil he would recommend, he can also ship you
more syringes of oil.

I did that, but no response so far except for an auto-responder saying something about tradeshows. I’m doing 118 miles this weekend so I want to at least have a backup plan. I’ll take my syringe and some good chain oil that I have lying around.

When the margin of safety is razor thin, and the stakes are high it is important to remember to never, ever risk an underdose! Well, that’s my life motto anyway.
I’ve got about 2,500 k on my Schlumpf. At first, I was very parsimonious about the green lubricant that came with the hub. I followed the rules. When I first injected it I noticed a significant loss of friction when pedaling. It was easier, especially in high gear. So I put in some more. A couple months later I thought the hub was getting sticky again so I put in the rest of the syringe. Again, it felt better. After reading the bit about “high quality bike oil” (whatever that is) I decided that gears are gears, they’re all made out of metal and what they need on them is slippery stuff. So I started putting in a few mls 10W30 every month or so. Yeah, it leaks all over the place, and that looks ugly, but a rag cleans it up easily. After a while I decided to try something a little more viscous, so I went to the auto supply store and jiggled all of the different bottles of oil. The “gear oil” appeared to be more viscous, so I got that. As a bonus feature, the bottle has a narrow spout that allows me to shoot a few mls right into the hole without having to first decant the oil into the syringe. Plus it’s a lot cheaper than the green Schlumpf oil. It still leaks all over the hub, the spokes and the floor, but my Schlumpf works like a dream. I don’t measure how much I put in, but I would guess that I put in about 2 or 3 mls every month or two, depending on how much riding I do.
Remember, even though the Schlumpfs are totally cool, nifty neato, and we love them to pieces, gears and friction are not rocket science. They’re something a little closer to kitchen chemistry. Keep them good and slippery.


I just know that Florian is going to read this and then tell me that the warranty is void. AAAK!


After reading this I realized that you’re right, I need to get less neurotic about exactly what kind of slippery stuff I put in there, and just get some kind of lubricant in that hub before my long ride. I was having breakfast at the time so I sucked up some congealed bacon fat into the syringe and injected it into the hub. I’m 59 miles in and it seems to be working well. As a bonus my hub has never smelled better.

Good for Bruce, but bad for me, since I was basically chasing him around the Bike MS course the entire weekend. The faster he’d get spinning, the more the hub would heat up and waft the scent of bacon onto the wind. I was constantly feeling hungry for breakfast.

And I bet the bacon fat doesn’t leak out of the hub as much as my less viscous gear oil. Bonus! Now, how to work some eggs and a mimosa into your Schlumpf maintenance…

The bacon grease will probably go rancid and develop some internal critters. A good environment can develop when they can get a drink of moisture when the coming cooler weather will generate some condensate in the hub. And yes, rancid equates to stench.

The positive aspect is that the fauna and flora might decide on their own to provide additional locomotion such as a mouse in a wheel.

Tasty bacon

I’ll work on those extra value items.

Now I’m on to a new problem. In addition to putting in the bacon grease I put in some bicycle grease. A few hours and 30 miles later my unicycle apparently lost the ability to shift from low gear to high gear. It has long been unreliable about shifting from high to low, but that is not critical. Shifting from low to high on the fly is terribly useful. After the 30 mile mark on Sunday it would freewheel every time I shifted on the fly.

Shifting when I was off it worked fine, so I switched to mounting in high gear and thanked the unicycling gods that I never had to do that on an uphill. However it is going to suck for my commute to work.

Other things that changed at the same time is that I shortened my cranks from 165 mm to 135 mm, so I may be misplacing my ankle, but it still shouldn’t freewheel and fail to shift!

Any theories? The obvious culprits are:

  • the new grease is no good and is gumming up the shifting spring
  • the shifting spring is old or bent and after a year of unreliable downshifting has moved to the next logical progression
  • it is purely a matter of poor ankle bone placement, and thus is all rider error

I’m trying to decide whether to take it apart or send it to Florian. I need it to be able to shift up reliably on the fly. That’s the whole point of a Schlumpf.

well i’am curious if florian will fixx your hub under warrenty because you put bacon fat in your hub, thats not like the recommended good quality bicycle oil.
hope you have good luck with it.:wink:

Hey Bruce,
sounds like you need to flush the whole thing out (somehow) with bike oil which might get rid of the grease but there’s probably big particles in there too. Whatever you do, don’t take the hub apart as that won’t just totally void the warranty, it could be dangerous: Florian doesn’t trust anyone at all to take apart a hub.
all the best

Bruce, it is possible that the grease plugged things up a bit, but more than likely, the button’s aren’t adjusted correctly. Make sure the buttons have a bit of push-in “play” when they are adjusted. If they are too tight (don’t push in a bit), then it is possible for one button to be pulling the shifter out a bit, and letting it freewheel. I’ve had this happen to me before when a crank came loose a bit and applied outward pressure on the button.

Other problems could be that the bearing holders are too tight. Try loosening them a bit. Another problem could be the cranks cranked on too tight. Try 30 ft-pounds on a new (or different) set of cranks (if you have them).

Also, make sure it really is free-wheeling, and isn’t it just moving up to 25/30 degrees to the point it catches; sometimes this feels like freewheeling and can make one fall.