Luckily, 2km down from where it broke there was a welder who fixed the T7 right back up. The schlumpf has been fine, we have four on tour 
Thanks for the advice, Iāll sure as hell follow it. First I have to call Schlumpf and tell him the bad news:o
Just to reiterate what others have said, you really must have enough torque on the cranks if you want them to stay on. 50-55nM is the spec and thatās what I use. I even brought my massively heavy torque wrench to India. We have 4 Schlumpf hubs in daily use on the tour here in India, and they are getting massive punishment, riding such rough rocky roads at speed in both high and low gears. No problems so far although when we checked on day 2, one crank on one of them had loosened quite a bit. This morning I checked mine and after 4 more days of pounding hard riding, including a 2000m climb and so much rocky high speed downhill, I had to tighten both about 10 or 20 degrees to get to 52nM.
I now have about 1200km on mine, and like James said, wouldnāt go back. Sure it is more finicky and expensive and heavy, but overall itās worth it to me.
Good luck with getting it fixed, then keep it tight. There is no way youāll get 50-55nM with a little hex wrench.
āNathan
Are the cranks on Schlumpf hubs somehow more prone to coming loose than on a normal hub? Arenāt they just normal square-taper or ISIS depending on the hub model?
I agree that you need a bit more torque on the crank bolts on a unicycle than on a bike (I tend to use about 30lbft on unicycle sq-taper, a bit less on ISIS) and have never had a crank come loose. Iāve had ProWheel sq-taper cranks full of fatigue cracks on a muni, but never had a problem with crank-hub interface. Why should the Schlumpf ones need 55lbft?
Just wondering, as there seems to be a lot of talk about this.
Rob
EDIT: Sorry, just noticed Nathan said 55Nm, not lbft - which is āonlyā about 40lbft. The gist of my question still stands though.
I also wonder if it has to do with wheel-size/weight where the schlumpfs are being used? Seems like a common thread is that the cranks are coming loose on the larger wheels (of course this is the most popular wheel size for schlumpfs 
). Still I wonder if Iāll have the same problem when I finally get around to putting my KH/Schlumpf in my KH24? While I donāt own a torque wrench, all this talk has got me a bit paranoid about damaging my hub! I think Iāll take siafiredeās advice and when I first start riding with the hub Iāll leave the shift buttons off for a bit and just learn to ride in the high gear and periodically check the the crank tightness over a few rides to make sure things are nice and tight. Hmmm, perhaps Iāll have to get a torque wrench? Heck I already spent quite a bit on this hub perhaps itās in my best interest to make sure I donāt jack it all up!
I donāt knowā¦ Iāve not had crank loosening problems on either of my heavily-used unicycles (26" muni and 36"). Most of my riding would probably be described as cross-country, with no massive drops or trials-like hopping, but certainly on the rougher/rockier side, and lots of miles. Both those unicycles were square-taper until recently, now both are ISIS.
I would imagine that most of the Schlumpf 36ers are being used mostly on the road, so they shouldnāt be subjected to excessive vibration (I know some people are using them for xc a bit as well).
If itās just down to riding style/terrain/etc then those same people should have had the same problems with normal ungeared hubs, rather than it being noted as a āSchlumpf problemā.
Sorry about sticking my beak in hereā¦ Chances are Iāll never have a guni anyway, thereās no way I could justify the expense (and Iām too chicken to go over 15mph on a unicycle anyway!), but Iām still interested in all this.
Rob
There seems to be a tolerance problem, either with the Schlumpf splines or the KH crank splines; they just donāt fit that well together.
Probably the reason it comes up more on the Schlumpf is that the Schlumpf tightening bolt is a 6mm hex keyānot nearly large enough to install something with the required torque. Other crank bolts are typically 8mm hex or 14mm nut; most people have decent tools which can crank those down well.
Seems a little harsh. Koxx is french kh is US. Been on the french forums? Maybe look at k1 service there as well, cause kh service is non existent there.
Now you could argue the US is bigger for KH, but France is bigger for K1.
As for this hub, well they are fragile by nature, they werent sold as bombproof by kh eitherā¦ Just seems unlucky to be plagued by so many problems.
I still am very reluctant to use that much torque when tightening the bolts on the schlumpf hub, I use much less than that and as I have said I have had no issues. Almost every unicycle I have owned has had its cranks come loose the first several rides. After the first 50 miles on my geared 29er, my cranks never came loose on my kh/schlumpf, same for the first 50 miles on my geared 36er.
I agree with Tom that some of the problem probably has to do with the 6mm vs 8mm crank bolt. I had a lot of problems tightening the crank bolt with the hex tool that came with the hub, I even almost rounded out the bolt the first time. Buying a nice hex adapter for a socket wrench allowed me to tighten with a smooth movement and put enough torque into it.
I think the best way to set up your new kh/schlumpf is to ride the first 10 miles without the buttons on. just keep it in high gear and after you ride for the first mile check the cranks, then check every other mile until you are comfortable that the cranks arenāt constantly getting loose. After 10-15 miles, go ahead and put the buttons on if you are confident the cranks are not getting loose all the time. That is the method I used, and it saved me the hassle of removing and attaching the buttons during my first 10 miles with the hub when I needed to tighten the cranks up.
I must correct you here. KH is Canadian.
Of course, CA riders are mostly on the english speaking forums, so I agree with much of your post, that the Koxx problems would be more likely to be reported on the French or other European language fora.
Guess what? Me too! Damn! This was maybe my 20th mile! Iād ridden my KH24 with the Maxxis Hookworm tire a few times to get a feel for the overdrive and switching gears on fairly easy terrain. My longest ride was ~10 1/2 miles on pavement. So today I swapped out the Hookworm for a proper MUni tire Wildlife Duro and hit up some gravel roads and light XC double track. I was about 4 miles into a 5 mile ride when I stopped to take a break. I was inspecting the hub and cranks and all the connections as Iāve been paranoid that the cranks would come loose and reek havoc! Anyways as I was inspecting the hub on the knurled bearing side I noticed a shriveled up piece of metal (see the top of this thread!) and I could see the bearings inside the hub housing! &^%###$^&$^&$!!! and double &(&($%#$%#$^!!!
So I just e-mailed Florian but I imagine Iāll have to delace this wheel and mail my hub, M0127, back overseasā¦
Still Iām not giving up on this technology. I understand there are still things to be worked out. Yes I could have waited until perhaps the hub was a few generations along, or less expensive etcā¦ But I want to use it now, to be one of the pioneers and explore the unique capabilities that a GUni possesses. I can tell you that once youāve tried one of these hubs in a unicycle you wonāt want to give it up!
I gave mine up, was a 24" KH frame guni muni. I canāt help but follow these geared treads, and sigh from time to time. Just never got to where I would dare try to shift on the fly, and so couldnāt justify the cost of the beauty.
Thatās sad to hear. 
I picked up the whole shifting on the fly fairly quickly, not really all that difficult just a bit of technique is all. Yeah Iām pretty mad that this same bearing housing issue happened to me, but I still think it will be worth it in the long run. I simply canāt get over the experience of riding at Coker speeds on my 24" unicycle and being able to down shift to wait at road crossings or to head into some single track trail. Iām with Corbin on this one, geared unicycles are not the wave of the future, the future is here now. Yes Iām very fortunate to be able to own a hub and despite itās apparent short comings the obvious utility I see in having a ādo it allā GUni more than make up for those.
Still I guess Iām going to be single-speeding it for a while
20 miles only? That sucks. Mine probably had at least 1000 miles before the bearings fell apart.
Best of luck getting it fixed and rideable again.
Whatās with the frown? Just wait until you realize the freedom of not having to worry about all the fiddly bolts. 
Iāll admit that Iāve not read back through all 7 pages of this thread, but I thought the bearing issue had been sorted a few months back. Where did you buy your hub from, and could it have been an early one that was sitting on the shelf somewhere for a while?
STM - Riding a Schlumpf hubbed unicycles a lot for 2 years now with no issues so far
Yeah, so true! But to shift, ah to shift is divine! 
No worries itās too hot/humid in these parts right now for any serious ridingā¦
Thatās interesting. Letās see I ordered my hub in November of last year, and finally received it around March. Then because of other issues I wasnāt finally able to get the wheel built until about two weeks ago! 
So I think the bearing issue must have been resolved sometime after I received my hub. According to the Schlumpf site the new bearings have just arrived (or just announced that theyāve arrived). I can tell from the photos on the site that Iāve definitely got the older bearings as those bearings are quite small!
I really must have gotten unlucky! The road riding set up seemed fine, but as soon as I went off-roadā¦ I wonder since this seems to always happen on the knurled bearing side of the hub if itās related to how tightly the bearing holder is tightened down? The only thing I can think of is perhaps I over-tightened the bearing cover on that side when I swapped out tires? The other possibility could be loose cranks? They seemed tight enough when I tested them multiple times, yet they were not very difficult to remove? 
In any event Iāll be sending my hub back for repair.
Thatās a bummer about your hub MuniSano, sorry to hear that.
My hub is around the same build as yours and is overdue to go back to Florian, part of which is bearing replacement under warranty (seals pop off mine exposing the ball bearings from time to time). I have to admit problems with my own hub and those of others introduced extra caution in the back of my mind while riding the GUni 36āer.
As much as I really enjoy the big gear feel (and speed) of pedaling the uni in 1:1.5 gear (yeah agree shifting itself is also great fun) I also agree with Phlegm re the āfreedomā of single speed uniās. I got back on my single speed 36āer the other week and after a few months on the GUni the single speed felt so light and responsive off road, and hassle/doubt free - really enjoyed just getting on and riding whenever.
Anyways, now that Iāve weened myself off the GUni itās probably time to send the hub back. I donāt think Iāll be building it back up into a 36āer afterwards - as much fun as the 36 GUni was, I think Iāll probably relax and enjoy it more on the 24 with less concern about problems.
Direct link to Schlumpf News.
Those bigger ones look cool, and Iām hoping that mine will have them when I get it back. My knurled-side bearing had started to make an occasional click/crack sound like there was a problem inside it, so it has gone back for replacement.
Though I hope they donāt make it even heavierā¦
Sam
My brand new Schlumpf is bad ā¦
M0207, one week old, less than 25 miles, sounds like broken parts and bearings loose and rattling inside, locks up the wheel and throws me on my nose. I sure was glad I was not clipless for this ride.
My wife, who got this for my anniversary, has a lot more *&#~! and $^!# to say about what it is like to be the proud owner of an expensive, bad hub.
Major suckageā¦sorry to hear about that. Also quite astounding the quality differences between hubs, where you have some that pounded their way around Africa with no problems, and others that seem to break just by staring at them hard.