Schlumpf hub servicing

So my Guni is on it’s way by courier as I write this. So excited

My question is, I have been reading all the posts on this website about troubleshooting hubs and adjusting the shift buttons etc.

I have a very very basic tool kit, and work space, and certainly no torque wrenches.
I feel a little apprehensive about doing simple things like switching tires, for fear of breaking it.
Do I need to be worries. How likely am I to break my beautiful unicycle, doing basic hinges with the uni.

Should I invest in a set of fancy tools torque wrench and all.
Or will I be ok with normal tools and care?

I’m not looking to take it apart and rebuild it, just change a tire, maybe change cranks later on


Yes get the Torque wrenches… I have 2… a light one for the caps (5-6nm) and a medium weight for the crank bolts (I set them to 50nm)… I also use a soft mallet to force the the cranks on. It is worth rechecking the crank bolts every month as they do come loose. BTW the M6 hex in the crank bolt strips easily, is a nightmare to get out if it does and very expensive!!! so get a good quality hex bit and replace the bolt with a new one as soon as you see any wear in the hex :stuck_out_tongue:

Definitely get the torque wrenches.
After stripping the head on one crank bolt, I now take more care. Wipe off the hex bit, and put pressure over the torque wrench to keep it seated.

I have a rubber mallet to seat the cranks, but when it’s not handy I settle for a small piece of wood.

Crank setting bolt

I posted a while about the stripping bolt. Some people suggest using a drilled out normal crank bolt to get the tension on the the crank first then take it out to put the schlumpf bolt in.

Personally I found it easier to use the rubber mallet on the crank and work up the torques 10nm at a time giving it a good knock between torques :sunglasses:

This is not due to lacking a torque wrench, but to using the wrong bolt to tighten the cranks. Use a rubber mallet to set the crank on a well greased spline, then use a standard isis bolt to torque the cranks onto the hub, then switch bolts to the Schlumpf and retorque.

The high torque “risk” is in overtightening the bearing holder and damaging the bearing. You can torque by hand if you’re are not a gorilla. Go to your LBS and have them do it first so you know how tight is enough. In general, I go hand tight and if the bearing slips I go a little tighter, no problems. I avoid removing the wheel in general.

In terms of keep the hub clean, the biggest thing I notice in the wider hubs with teh dust shields is the lack of clearance tends to make it harder to clean out the greasy dirt from between the hub and frame. It’s so tight that a single sheet of paper is all that will fit, so I use a sheet of paper to clean that space.

Personally, I don’t ride the guni in wet weather or wet conditions, it’s just to expensive and hard to clean, but the folks that do seem to have few problems since the delicate parts are internally located.

Other than that, enjoy your hub.

LOL… where I am from I dont get the choice not to ride in the wet :slight_smile: … yes its possible to tighten things without using a torque wrench, but I think its better to if you are nervous about it :slight_smile: …BTW the new hub is pretty wide, I found even after I filed the frame to give the 1mm clearance after 1k riding the dust cover would pop out (I presume the oil getting warm and pushing some air out) and would still rubb on the clamps… I just filed it a little more and it was fine :smiley:

Yeah, I’d go further and say TOO WIDE, but who ever listens to me :roll_eyes:

I think it’s time for a new hub standard, 100mm just ain’t enough any more to accomodate all the bells and whistles, geared hub, disc brakes, longer splines, etc…

Another 20mm, 120mm spacing, would be a nice start, on par with the Nimbus disc hubs.

As it sits now, KH will need to redesign the bearing holders/frame welding to provide sufficient spacing for the new Schlumpf hub, filing at home ain’t gonna cut it, the legs are too close and aggressive filing will weaken the weld.

I think the Nimbus hubs have more clearance…

I agree with everyone else: get torque wrenches. I am using the Park torque wrenches and am reasonably happy with them. I got a Wiha torque wrench especially to set the 2 Nm torque in the shift-button screw.

Good luck with your new unicycle!


Yup… it would be really nice to have a disc brake built on to the hub itself and still have the ability to swap cranks :slight_smile:

Fatlazypig wrote

I have a very very basic tool kit, and work space, and certainly no torque wrenches.
I feel a little apprehensive about doing simple things like switching tires, for fear of breaking it.
Do I need to be worries. How likely am I to break my beautiful unicycle, doing basic hinges with the uni.

When we are apprehensive about switching tires, our skill levels and mechanical experience are not going to allow one to do more difficult tasks well. I certainly also recommend the torque wrenches, but it sounds like Fatlazypig is much better off having his unicycle serviced rather than servicing it himself. The place to improve mechanical rebuilding, fixing skills, is on cheap disposable items.

NOOOOOOO!!! Please do not make the hub any wider. Racing with the wider (120mm) hub is extremely uncomfortable for me. There is a reason that the two dedicated track racing unicycles (Nimbus and Qu-ax) have hubs that are even thinner than the 100mm standard. I do agree that the newest hub is a little bit too wide. My frame is powder-coated and that little extra thickness on the bearing holders was too much, I not only had to file the welds but actually in the inside of the bearing holders a bit.

My thoughts are at this stage to get the tools some good quality hex bits. And the torque wrenches. But limit myself to changes of tire

To take the wheel off I just need to take off the bearing covers ( is that the rigt word) then not crush the bearing when replacing ( use of torque wrench here)

Then get it serivced ? Monthly? To check cranks etc at LBS. As I get more
used to things may do more myself but I do want to be able to switch out 1 tire for another

Does this sound reasonable?

I honestly don’t think torque wrenches are necessary- if you know what you are doing you can get away without them. In fact, because the tolerances with cranks and such vary quite a bit (even among the KH moments) they can lead to nasty situations. I’ve seen people push their cranks on their schlumpf axle to the point where they hit the frame in search of their torque wrench’s ‘click’.

A few important points have been touched on in this thread though- use a standard 8mm KH crank bolt to seat the crank- and then replace it with a moderately locktight-ed schlumpf bolt. The schlumpf bolts can strip- so don’t use them for the heavy tightening work.

Make sure you clean out all the dirt/mud from your tiny shifter button grub screw before trying to adjust it. If that gets stripped- you are f@#ed.

Don’t crush your bearings with the bearing caps. Firm will do- if your knurled bearing slips, then you know to give it another 1/4 turn.

Hope it goes well for you!


ps: Nurseben- Considering how much your opinion on gear has changed as your riding has developed- I don’t think you could honestly expect major manufacturers to alter their designs on your latest whim:o. The 100mm spacing is fine- KH is releasing outboard disc brakes next year so there is no need to make it wider. I’m sure the frame rub situation will be rectified in the newest batch of frames.


The only reason for a wider hub is to make a stronger 36" that does not flex (causing brake rub on a rim brake). Seems less reason for that now with disc brakes

I’ve been doing without one so far, but a lot of it is coming down to guesswork, and there isn’t much room for error. I notice that the shifting seems to be affected by how tight you’ve clamped the bearings or the cranks on. Another example was when I overtightened the grub screw in the buttons- took a lot of headscratching to come up with a way to remove them.

I think I’ll see if I can pick up a torque wrench cheaply online- they all seem way expensive.

It is true that in my 3 + years of unicycling my preferences have evolved, but my evolution is not unlike the evolution of most riders in that preferences change as skills change. But my skills did get to the point that a Schlumpf was the next step, so what I’m saying is that if a mfg does not pay attention to their entire constiuency, then their product will not be as accessible/usable, which will decrease sales, decrease appeal, etc…

Now Napalm, you are a strong, young guy, so what works for you is not the “norm” for an an XC rider, in the same way that Turtle is not an example of the average muni rider. So even if you like something as it is, there are many riders who are dissatisfied with the very same product.

Schlumpf owners are a unique population, both for their willingness to put up with a fickle product and their ability to pay a steep price to access that product. There are far more unicyclists who don’t own a Schlumpf than do, and there is a fair number of folks who have given up on their Schlumpf for various reasons.

Realistically, the sales for Schlumpf hubs has been fairly flat, for many reasons (cost, access, durability, small market), so if this aspect of unicycling is to grow, then it needs to change:

More gear ratio choices, disc brake, fewer user end issues, and a improved access. For now and the immediate future, owning a Schlumpf is akin to owning a Maserati; the nearest Maserati dealer to me is in Atlanta, four hours away and gawd forbid I need parts or I break down while driving around town.

Say what you will, but you know I’m right, so let’s not beleaguer the issues with Schlumpf, just as you should refrain from telling me that my lack of experience are the reason I don’t like riding a Schlumpf :roll_eyes:

The next generation of Schlumpf buyers will be like me and mine vs you and yours, ie newer riders with evolving skills.

I just wanna be a bug on the wall when you crawl out of bed at age fifty and complain about your back pain to your wife :smiley:

Awesome, I didn’t know about that!

Not the most compelling way to make a point (I’m not even disputing what you are claiming above). :roll_eyes:

I’d also like to see most unicycle gear stay mostly the same, or at least if changes MUST be made they should be as an alternative not the new “rule”. Options are good but forcing a whole new paradigm w/o good reasons isn’t. Disk brakes? Sound great, but I’m fairly happy with my “old fashioned” hydro rim brake, why change things up? I used to have disk brake on my fixed-gear mountain bike; was such a pain to constantly adjust that I just removed it. Keep it simple! If folks want disk brakes so badly then great, add some more hub width/frame options but don’t assume everybody wants the new features…

As for my KH/Schlumpf hub, I’ve been nothing but 100% satisfied with mine; been getting steady use out of it for the past 2 years w/o any issues; totally great for the kind of riding I do; can’t imagine NOT having it.

General comments about skill development and gear changes: I’ve always been of the mindset of not spending a whole lot of money on every new thing that comes along (yeah, I have a Schlumpf but that’s a long story). I take great pride in getting the most out of what gear I have and expanding what I can do with it; pushing my skill level with what I have. While I’d love to be able to throw money down and try all sorts of unicycle designs, sizes, tires, rims, brakes etc… the reality is I can’t afford to and so I do what I can with what I have! While my KH24 GUni may not be the best unicycle for all occasions, it’s taken me on many epic adventures over the past 4 years of use: from descending 14ers in Colorado, to 12 hour single track mountain bike races, to 100 mile road rides and a whole lot of riding in between; all over the country! My moral is simply to tinker less and ride what you have more! Ride it until it breaks! :slight_smile:

Ben- I can understand your concern about the reliability of an expensive product, but that comes part and parcel with being part of a very small sport where the products are complex and the conditions they are used in- testing.

However, You can’t say you are at a level of riding where you need a schlumpf, then backtrack and say you want different gear ratio’s for it. The step in gearing and learning to tame, even exploit it, is part of the skill.

Using your car example- you wouldn’t go out and chuck a 4 speed auto in a ferrari to make it more accessible to regular drivers. You need to keep the high end gear for high end riding.

You will continue to develop as a rider, and one day come to realise the benefit of the design- and then you will be like me, trying to stop other people wanting to dumb down the high end equipment because they haven’t quite got the hang of it yet.