Road Rash supreme!
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When I bought my Schlumpf hub, I had it installed in a 19" wheel. Pretty silly, I know. But I had a lot of fun riding it. At my top speed, I had to run out dismounts. After two years with the G19, I reinstalled the hub into a 26" wheel. I haven’t ridden the G26 that often, and I’m kind of wishing I’d stuck with the G19. It was great for practicing shifting. I installed my Shadow handle on it and took it on long muni rides.
Just pointing out there are options other than selling the thing…
Your wise and right, but I have many more home made uni/muni’s to choose to ride and injury has made me rethink the stable. I also have a road 36" that gets up to a fast pace and would be pretty bad on old knee’s lf I went down. My 29" Schlumpf is an early square taper road hub as that was all available, so it never has seen a trail or drops, just speed.
A couple questions for the more-experienced Schlumpf riders:
I pulled out my G26 yesterday after a year-long break from it. I did some maintenance and tightness-checking before my ride. Every spoke was greasy and covered in dust. I am assuming Schlumpf grease leaked out of the hub during the previous rides. Every spoke seemed to have an even amount of grease on it. I don’t think any grease spilled out from the unicycle just hanging in my garage. Is this normal?
I am using a lightweight mtb tire (Schwalbe Smart Sam) on my G26. I pumped it up to 38 psi. A few times during my all-paved ride, I felt the uni was bouncing up and down, as if it found a natural frequency of vibration. This made me feel out of control while it was happening. I am confused whether I should pump the tire to a greater pressure, or if I should lower the pressure…to eliminate the weird bounciness. At higher pressure, some of the bumps in the pavement might knock me off. At lower pressure, there is greater rolling resistance. Any ideas?
My ride ended with a somewhat challenging uphill. When I got back to my neighborhood, my legs felt tight, and I was walking with a shorter gait. I have had this experience before after riding in high gear and when experimenting with shorter crank length on my un-geared unicycles. It makes me tight.
It’s hard to be a “sometimes” geared rider and get much satisfaction out of it. It takes practice. My G26 is so much heavier than my other unicycles, as well, and that makes it feel sluggish. Riding at higher speeds is fun, but I’m not well-equipped to crash at those speeds. I should either practice more on it, install it in a smaller wheel (it started out as a fun G19) or sell it.
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I had similar issue with my 36" in country side trails full of bumps. At 60 PSI I was almost always standing to avoid UPD, at 40PSI it was good, now I’ve set it to 35PSI with a dampening tire insert and I’m increasing my speed greatly even sitting on medium bumps… so if you ride offroad consider the dampening as the main factor to achieve: it has a greater importance than other factors and it influnces also the Watt absorption of the tire reducing the rolling resistance. I read (and tested) various articles about road ciclyst overpumping their tires… using differents type of efficiency measurement it came out that a pumped road tire at 9-10 BARS absorbed like the double of a 7-8 BAR bike tire. And the new trend is becoming using tubeless and the lower part of the suggested pressures from a specific tire given by its manufacturer (which seems to better understand the properties of the rubber used)
Trying to take apart a hub to do a complete clean and try an ATF oil bath.
Based on the How It’s Made Video,
I unscrewed the 9 T20 screws on the right side, but nothing happened.
I thought the left side and sun gear would be stuck as it was pressed in, but next I took out the two snaprings near the clamped frame bearings.
After I took out the two snap rings, and the sun gear + bearing came out. The large bearing was a super loose fit in the hub body.
The right-side plate and rest of the mechanism still seems stuck. I’m afriad to use too much force.
I noticed three M5 threaded holes on the right-side plate. Are those supposed to be used to pull the plate off?
Update:
I made a plastic piece for me to grab onto the right plate. My thought was three holes for the M5 screws to go through, and I could clamp the plastic part in a vise and pull.
But, I accidentall tightened the M5 bolts “too much” and heard small sound. It still felt stuck though.
Putting it in the vice, I couldn’t get it out as the plastic piece didnt have enough friction and was too weak to be clamped hard.
I became impatient and continued tightening the M5 screws more. It popped the plate off!
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The whole Schlumpf Hub is a slide-fit assembly, it’s normal that everything is ‘‘loose’’. ATF will just leak out and contaminate your brake pretty quick, as well as throw oil on your spokes and around your wheel. The oil/grease Schlumpf uses is a NLGI 00 grade, which is kinda similar to yogurt. It’s hard to find but I managed to order some at my local car parts store.
The 3 M5 holes on the grey part are meant to use as a puller, you put 3 bolts in and equaly tighten them until the thing pops out.
It’s a fun puzzle, take your time, there’s 2 hidden ball bearing and springs in there. You dont want to lose them!
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Given how loose it is, I am a bit more worried about leakage…
I read people replace grease in their older shimano alfine/nexus 8- speed hubs with atf or gear oil. But also some people reverted due to too much leakage.
I wanted to try it, assuming lighter oils are more efficient, knowing it might have more leakage problems. My bigger worry now is if it might cause problems (swell or disintegrate) with the rubber seal on the planet carrier or other bearings.
I would be interested in trying NLGI 000 grease, but that seems much harder to find
I already had one spring shoot out, but found it on the ground 
My biggest worry would be the simple fact that lighter oils do not like to to stay in place - especially the places where you would need it for lubrication. Gearboxes that use oil are designed to have a puddle of oil at the bottom, which gets splashed up by the gears running through it and distributed to where it’s needed. Obviously that requires oiltight seals (as opposed to dust tight, like the Schlumpf hub has)…
Your money not mine, but with the price and low availability of replacement parts, I’d be pretty careful with lubrication experiments - those gears will not like running dry, even for relatively short distances. The 0-3% of efficiency you may gain don’t seem worth it to me, especially considering that a single stage planetary gear like the schlumpf is already fairly efficient by design.
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Really admire your tenacity in taking your hub apart. It would be magical if there was one day a fully photographed service manual, ideally from Florian himself - but as that’s unlikely, one crowdsourced from say the photos you take (and others) when disassembling the beast, would be ace.
Perhaps the new hubs could be a chance to ask (nicely) if Florian could photograph each stage of its assembly.
Back to the task you’ve undertaken. I’d not dare to take apart my 200 series hub unless it was completely faulty. And even then I’d rather pay for a service than risk making it worse.
I did once wonder if one could improve the longevity of the device but doing a kind of engine oil change - flush out the stuff lingering inside with fresh. But that doesn’t seem needed really as it leaks out slowly by itself.
I haven’t in fact found mine to be that oily or the official schlumpf grease hard to find or stock up on. I got two tubs of the stuff and have already filled up enough syringes to last me until 2050 and that’s with 1.5 tubs still remaining to decant to more syringes.
My gut also says to basically stick to what Florian uses as there is going to be a sound reason for it having been chosen as the grease to use.
I’d be interested to know however more about the motivation behind this conversion to an oil bath 
Yup, that works nicely!
Do you know if the clutch halves with springs, 3 pins, and 3 bolts, are a press fit? The three bolts were super tight. After getting those off, the two halves were still really stuck…
Schulmpf bike hubs actually say you can use oil, so I’m not too worried about it being too dry.
I’m hoping it’s 1%! That’d be over half a minute for a 1 hour climb! But yes…who knows if it’s 0% 
I’m assuming you’ve helped service a lot of them! Have you noticed them being rougher after taking apart?
Shimano Alfine hubs which people take out to dip come out with all the gears (sun+planet+ring) in one piece.
For our Schulmpfs, the “indexing” of the gear teeth are lost. Given the gear teeth count aren’t relatively prime (66t/14t/36t), it’ll more likely than not go in differently than it came out. No idea if this is a real concern; I’ve heard of “breaking in” parts; wonder if this is similar.
With just the hub in my hand, I can feel a rought spot when turning the axle in high gear. It’s definitely the gears meshing as all the bearing were smooth when I took it apart. Mine only has 500 miles, and it always had a rough spot. I’m just not sure if it’s worse or the same, and just needs breaking in.
Pictures of the bath:
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I would never use ATF in a Schlumpf as it’s not a lubricant. In a gearbox, the ATF is not used in the part with all the cogs, it’s used in the part with the hydraulic clutch system.
It is, tremec even uses ATF in some manual transmissions.
Power and speed are not linear, if you are in high gear on a Schlumpf, you can’t neglect air resistance…
Do you know if the clutch halves with springs, 3 pins, and 3 bolts, are a press fit? The three bolts were super tight. After getting those off, the two halves were still really stuck…
Use a large flat head screw driver and slowly pry it. Do a little on each side so it comes off evenly.
I’m assuming you’ve helped service a lot of them! Have you noticed them being rougher after taking apart?
Shimano Alfine hubs which people take out to dip come out with all the gears (sun+planet+ring) in one piece.
For our Schulmpfs, the “indexing” of the gear teeth are lost. Given the gear teeth count aren’t relatively prime (66t/14t/36t), it’ll more likely than not go in differently than it came out. No idea if this is a real concern; I’ve heard of “breaking in” parts; wonder if this is similar.
I’ve taken easily a dozen apart for complete rebuild. From just a full deep clean to defective hubs 
Hubs usualy come out smoother than before. I dont think those need a brake-in since it’s always the same gears at the same place. Just have to make sure it’s clean clean clean clean otherwise you would end up with rough spots.
Whenever I get one to clean, I clean it 2 or 3 times before I re-assemble the whole thing. I make sure it ships as good as new!
I’m confident you’ll loose all your oil in just a couple rides. Even new hubs with the Schlumpf grease leak a little because of the slide-fit assembly.
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Agree that it is a lubricant, but also definitely not our normal schlumpf grease. Risking it with this schlumpf but will also carefully inspect after a few rides. I have a syringe of grease left, so can abort this experiment anytime.
True sometimes. But I’m mostly interested for my G700C for hill climbs. 6% grade, 16km/h, ~80rpm, on a 700C/650B. In this case, aero is less than 10%, and gravity is the main component and thus approximately linear. (One could argue that an ungeared 36 is better in this scenario…)
Of course, for G36ers spinning 100+rpm at 30kph+, aero and balance/skills would be a lot more important. I definitely wouldn’t consider this experiment for G36 speedsters.
Thanks, I’ll try that next time.
I definitely was not up to par on cleaning, as you might be able to tell from my pictures. Dried up loctite, lint from paper towels, dog hair, kind of was all over the place… I assembled it for now, but I’ll take it apart again in a few rides to double check anyways.
Another question hopefully Jacob you could help with. Do you have a torque value you use for the 9 side plate bolts? I asked Florian, and he says he doesn’t have specific value for them and just do them up reasonably.
Those 9 bolts + the 3 clutch bolts were both superrrr tight to undo. The 3 clutch bolts, I just tightened them about as tight as they were to undo by hand(maybe 7nm?). However, the 9 M4 side plate bolts started to feel like they were “soft”. Even if I turn them more, torque doesn’t seem to increase. I checked and they are at about 4.5nm. I’d say that is reasonable, but just doesn’t match how hard it was to undo them.
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I dont remember what torque I put them at. The 3 inside ones are really tight. The 9 outside ones dont need so much.
I asked Florian, and he said he has no spec for the outside ones, and to just do them up reasonably tight.
Any idea what type of bearing the planets are on? Is it just a bushing need bearings? I see pictures of Shimano Afline hubs, and their planets are on needle bearings. Whereas, Sturmey archer hubs look like they are just a bushing/pin. I’m not sure how to get it apart (not that I need to). There is some play in it though, which you can see in the video above.
Also, an update on ATF soak:
It has been almost 2 months since my ATF soak.
I have about 6 hours of riding on the guni. Over 3/4 of the distance in high gear.
Took it apart, and there still seems to be lubrication everywhere. But a lot of it seems like leftover grease. It steadily leaked over the first month. The last month has a lot less leakage. I’ve always left the wheel upright, to decrease amount of leakage.
If i really wanted to try ATF, I guess I should clean out all the grease. I’m a bit lazy…so going to see if soaking it in ATF overnight will soften and dissolve the grease this time.
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Hey everyone - slightly embarassing situation here… I was doing up my hub today for a bit of routine maintenance (It’s not really been ridden at all this year so gave it a fresh lick of grease and a yank up with the torque wrench) and I’ve managed to drop one of the tiny grub screws that hold the shifter buttons into the grass and of course it’s completely disappeared. Does anyone know exactly what size these things are so I can hunt for a replacement online? Hoping they’re obtainable from a hardware shop or something as the buttons seem to be out of stock on UDC UK 
Do you have a strong magnet?
Ha! I’ve been magnet fishing my lawn for hours to no avail. No idea where it’s gone!
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