Gotta try everything once I guess. I’ve been riding many kilometers on the Nimbus 29" and it would be nice to go a bit faster with less effort. I guess if I start wearing knee pads now, I will dare a bit more 
20" Schlumpf Update
I spoke on the phone today with a representative of Silva Cycles, the bike shop who installed a Schlumpf into a 19" wheel for me. After four days of riding, one of the cranks loosened, and the shift button got stuck. I was unable to remove the button to assess the damage, so I sent it back to Silva.
Now, I’m not very technically minded, and I’m hoping that someone else on the forum follows up on my post to clarify the situation…
The Silva rep. told my that he was only able to tighten the crank bolt to 18 nM before it bottomed out, and this was no where near the 40 nM specification quoted by Florian Schlumpf. The rep. told me that the situation could be remedied by refashioning whatever the part is that the crank comes flush with…when it’s bolted on, but that it takes a machine shop to do the job. Silva noticed the same problem when they were testing out a G36 they were putting together.
It sounds like the problem can be fixed, but since, I understand, this problem is without precedent, we’ll have to see how their solution plays out.
Needless to say, this is very concerning news. Of course, I hope the problem can be remedied. I am curious how many people have already put together Schlumpf unicycles, and what their experience is tightening the crank bolts, if they used a torque wrench, if they bottomed out, etc. My understanding is that this issue applies to EVERY 3rd generation Schlumpf.
I am very happy to work with Silva Cycles on this, because without their help I’d be SOL.
Are you using a disk brake? If you are some modifications are likely necessary to make things line up properly on a 3rd generation hub (pre #800).
If you aren’t using a disk brake your cranks should be fine. The cranks will go on a bit further than on a standard hub due to the shorter spindle but most people don’t experience clearance issues when using new cranks.
I have used blue loctite on the crank bolt on an “under-torqued” disk side and it held fine while still being relatively easy to take apart after. Don’t use red.
Oops, maybe I’m misquoting what “3rd generation” means. I am talking about a new hub, M0871 (Is that 4th generation???). Silva Cycles has installed a lot of them, and they told me there’s a problem, and the implication is that it applies to ‘all’ of the newest batch of hubs. There is no disk brake with my unicycle.
That’s interesting. You would think with the new crank stop you could just torque the bolts up to spec without worrying about it. 
It’s hard to say what “generation” a hub is in, there have been some incremental changes with stronger planet carriers and bearings etc without changing the outer shell. You have the third design of external shell so 3rd generation is valid, but confusing.
Maybe if I am bored one day I will go through this thread and figure out what serial numbers demarcate what changes…
I also have a 4th generation hub (M0852). Municycle.com built my wheel and installed the cranks. They seem to hold up very well untill now. I didn’t have the time to ride it that much, but normally I retighten cranks after the first 10km and I couldn’t move the wrench a by single degree.
which cranks are you using? Did they use the integrated crank stop? What do you mean by “he was only able to tighten the crank bolt to 18 nM before it bottomed out”? The cranks shall go against this new crank stop rings and then you can torque it as specified. Or were the bolts too long?
I only noticed it during the beginning of pedaling right after the freemount ended.
I actually just started riding in high gear without wall assistance, etc. - normal freemount.
I guess it simply trains the brain and enforces it to make the required fine tuning which eventually allows you to ride the unicycle; without really knowing what we do right or wrong…
The entire process took me I think between 10-15 minutes, which was pretty hard for me to take (as it’s only a freemount after all…), but then again it reminded me of a few years ago while I had moved from 20" to 36" unicycle.
It felt the same in terms of training your mind to this new wheel moment, power required and general rotation/ inertia.
I will upload a short video soon of my first practice from yesterday.
Good luck!
Nathan, thanks for sharing this!
I’d like to adapt your method of mounting in 1st gear only.
Could you please direct me to any tutorial on how to perform correctly the process of pushing the shift buttons? For example: is this done when the foot goes up or down the pedal?, etc.
Thanks 
Thanks one4all:D
Thanks a lot!
so the one I got isn’t the latest gen. The uni I got yesterday has an M0837. I take it that one doesn’t have any issues then?
M08xx is generation 4 which is the latest one
Regarding generations we should follow what Kris stated here not to make to many mistakes: Schlumpf hubs: general discussion.
Silva Cycles has installed many Schlumpfs in the past, and they are a re-seller of the Schlumpf hub. If I recall correctly, I was told that the spacer was too wide, and that it needed to be sent to a machine shop to be corrected. With the spacers on, the cranks could only be torqued to 18nM before hitting bottom. So, the problem is not the lack of a spacer, but the spacer itself.
I think the one you got yesterday is the latest generation. Mine is M0871 (definitely brand new), yours is M0837. The impression I got from talking to Silva Cycles was that this was going to be an issue for every mUni hub of the latest generation, assuming Schlumpf machined all of them to the same specifications. Silva Cycles told me they were in the process of building a G36 out of another one of the newest mUni hubs, and that they were dealing with the same issue.
When the crank loosened on my G19, I probably didn’t catch it quickly enough. Part of the reason was because the tiny bit of motion present in the normal working of the Schlumpf … it masked the looseness of the crank. I am pretty OCD about tightening stuff in general, and I feel stupid for not catching it earlier. I don’t want anyone else to have that problem.
What exactly do you mean when saying the bolt bottoms out? Coming to a hard stop, or leaking? Both is not easy to digest …
I strongly recommend not to refashion anything, but to address that issue to Florian Schlumpf.
Out of curiosity: what is your use case for a G19? I have a G20 myself, using it for traveling as it can be taken on a plane very easily without any extra costs. So when traveling for business I usually have it with me for local commuting.
Yes, it is. That generation of hubs starts at serial 800. Up to now there are 70 hubs available. All manufactured in a single batch.