Schlumpf hubs: general discussion

A query for all you Schlumpf commuters out there. This is more or less swaying my decision in my head.

Where I work, the bike racks are not sheltered. I absolutely do not want to leave a grand and a half worth of uni out in the elements, especially with a piece of machinery at the heart that I absolutely can not afford to let rust away!

What do you guys do in this situation? Find something to cover the wheel up, find a better place (indoors) to put it, or just forget the Schlumpf and ride your single-speed uni? Or… Just let it get wet? :astonished:

As the majority of my riding is the work commute these days, ‘get a Schlumpf but don’t use it for the commute’ isn’t really an option! :smiley:

I take mine in.

David: I would definitely check to make sure your crank isn’t getting loose. If your buttons were adjusted properly, you could shift, and then you couldn’t: something changed.

Loose cranks can be dangerous on a schlumpf. A dab of blue loctite on your crank bolt is a good insurance policy.

Piece Maker: I leave mine locked on the bike rack outside. The quick temperature swings going indoors to outdoors and vice versa is more likely to introduce moisture to the hub than being left in the rain.

Where I lock mine up is under a roof but if it wasn’t I would just put a plastic bag on the saddle if I thought it was going to rain.

New schlumpfer! What crank length do you recommend?

Just pulled the trigger and am getting myself a KH26 with the new schlumpf. :smiley:
I have all options sorted, except I am still undecided on crank length: 117/137 or 127/150?

I ride with 150 on all my unis (ungeared) - from 24 to 36. I like that length best, but for the Schlumpf I think I might want to go shorter:

  • I have small feet (UK 7 1/2) - I have read it will be hard to reach for the shift buttons. Is that a big deal or can I learn to work around that?
  • in direct drive, 26" with 150mm will be quite long and slow… but at the same time I should be able to use the high gear in more situations (hopefully on technical terrain too)
  • as for the 127 hole, I think I would end up stuck in direct drive except on flat-ish terrain (I don’t have powerful legs, rather a spinner). Not ideal, I would really like to use the high gear in relatively technical terrain too.

Now if I go for 117/137, I know I will likely never use the 117 hole. Not a big deal I guess. How about 137, you reckon I can use it much in high gear on relatively technical stuff? If so, I think this would be the right choice for me.

Leaning towards the 117/137 but am open to advice…



Hi, gonzo and welcome to the guni’s wold :slight_smile:

I’m pretty new in geared unicycling, I only have few rides on my g26 that I quickly transformed from Gmuni to road/XC guni (with a light 26x2.35 road tyre and tube).
In the first place I had the 110/137 spirits and I did my first tries with it but since I liked the 125 on some of my other unis I bought a 127 spirit crank.
This was a single hole, should have bought a 127/150 instead cause It appeared that 127 was nice in 1st gear but didn’t allow me to really exploit the extra speed, it takes me too long to accelerate and I don’t go as fast as what I was achieving with 137s.

With the 137 I didn’t manage very well to shift (in the first place), It was way better on 127 but shifting with my heels was definitely not my stuff.
Instead I have made some shifting pads with the round part of some spoons (soap spoons) that I attach to my shoes with wide and long elastic bands (and some scratch to prevent the round spoon bit to slide and fall).
Thanks to that I can shift at will (at least on 127s) with my ankles even when I use pedal extenders.
there is a post in this long thread where someone else used this kind of stuff to shift.

I didn’t put the 110/137 back yet but my next try will be with those, and I presume my “spoon” technique will work as well.

There is a good chance that 137 or 150 will work for you, but if you wonder about your ability to shift with 150s maybe you could use the same kind of DIY stuff that I use and shift with your ankles instead of you heels.
The part that kicks the buttons must be a little hard.

It’s a pity nothing close to 137/150 dual hole cranks exists, cause 137/165 does exist but I don’t imagine myself riding in first gear with 165’s, nor shifting with such a long cranks (don’t know where I would put the spoon bit)

You will probably find it hard to ride in 2nd gear in the begining, even with 137 cranks, IMO 137 is the shortest size that a beginner should use in the first place.

If 150s are your favorite length for all other riding, I would definitely recommend the 127/150s. The 150 length will be good while you learn to ride in high gear, and you can switch to the 127 length later if you want.
Although most guys shift with their heel, a few of us shift with the ankle. (That’s how I do it.) Then crank length doesn’t matter. The “spoon” adapters sound a little complicated. If you wear high-top shoes you shouldn’t have any problems. (That’s what I wear.) I even shift with low tops once in a while, and it’s ok as long as you do it gently. and don’t bang your ankle against the crank.
Good luck!

Are you open to the idea of running 137s on one of your other unicycles? maybe the 24, or the 36?

If you are then you could get the 117/137s for the GUni and if you don’t like it on the geared unicycle swap out a pair of 150s and try them on something else. I like having options and experimenting myself.

I have 137s on my G26 at the moment and am thinking of swapping them for 125s now that the snow has melted but it is a great general size for me.

Finaly managed to fix my two issues.

A little reminder:

All begins when I want to remove the 127s for putting back my 110/137s.
Impossible to remove the right 6mm crank bolt, everything I try just damage the hole more and finally it gets perfectly round.

The cause: WAY TOO MUCH LOCTITE+ bad quality tool in the first place.
Solution: hammering a T45 Torx key and heating the bolt during 60s with a blowlamp to break the loctite.

So, I finally managed to avoid the not so sexy “cut the crank” solution, and removed this stuck bolt, but… when I started to install the 137, everything was going well until I try to screw the gold button.
I feel a big resistance and I try to force it (second mistake).
Issue 2 : the thread of the shifting shaft is damaged and so the gold button is.

The cause: The hammering must have deformed the head of the shaft, and by forcing the bolt to be screwed in it damaged both the shaft thread and the gold button.

Solution: Bought a set of thread cutter (and a pair of buttons) and restored it this afternoon. (thanks to florian for all the advice on emails)

It would have been very simple if the shaft was not freely spinning inside the hub. this is how I blocked it while screwing the thread cutter:

The 3 m4 nuts were a good solution to keep the shaft from spinning while I was screwing the thread cutter in the other side, but unscrewing the nuts or the cutter when it was a little stuck was the complicated part.

Anyway, I managed to put the 110/137 back and gave a quick test 1h ago on my parking (137 hole) and found it way easier and stable to deal with the 2nd gear than with the 127s.
The shifting was good as soon as I installed my weird spoon system on my shoes (weird but efficient) , but now that all works fine I will probably pull the trigger for a pair of Five Ten shoes.

A last tip:

Before this two issues I was worried by a strange noise (crwik, crwak) while riding.

The cause: It as just my hub needed some special grease.(second hand that has not be used for a long time by its previous owner)

Solution: added the syringe of grease that came with the g26.
Since, I ordered a set of syringes from florian and just put another half syringe to be sure just before my quick test.

Hop this will help.
So remember: DO NOT USE MORE THAN ONE DROP OF BLUE LOCTITE if you decide to use some.
If something goes wrong: NO NOT FORCE before knowing what is going on.
If your bolt is stuck and you apparently can’t remove it DO NOT CUT YOUR CRANK before being sure there is nothing to do.


All sorted. Thanks!

Thank you Eric and Jakob (FB UniChat) for answering my questions. I’ve studied pictures of a disassembled hub but this thing remains a magical mystery shifting box. Lesson learned, the little stick (with threads) you see in the middle of the crank bolt when you take a button off (the stick you screw the button on) does NOT go all the way thru from silver to gold buttons. It’s actually two different sticks, one for each button.
Also, thanks Eric for reminding me to retighten the crank bolt after my first couple of rides. I busted out the Park torque wrench and brought the left back up from 35 to to 40 Newton meters to match the right which hadn’t budged. Reading about the trials and tribulations that UniDreamerFR had with a rounded off bolt, I’m tempted to order a set (per unit CHF 16) of spare 6mm axle bolts. I own a set of long KH 8mm bolt that I use to “set” the cranks. One of my 6mm axle bolts is slowly rounding off and I’d rather spring for a new set than take any chances.

137 on my g26: better than 127, but still a bit hard.

Update: Since I managed to put back the 137’s on my g26 I had a longer test ride this morning.
About 13km around a lake, 8km in 2dn gear.

Shifting was easy, riding in 2nd gear was way better than with the 127s, but still a bit hard for my knees (especially the left one), forward/backward balance was also more under control than with shorter cranks (never fell down) but it was still a bit too much physical to be 100% enjoyed.
My ability to accelerate was way better also, I managed to hit 24.6km/h vs 21km/h on 127, but my limitation was not coming from my ability to pedal fast but from the fact that balance and torque needed to go faster were too high (and didn’t have the balls) with such a crank length for my own level.

Remembering my last 33km ride on my ungeared 36er (last Monday) where I decided to use 145 cranks instead of 137, (trails/XC) and pretty much appreciated this size this time (I use to prefer short cranks) I decided to order a pair of 127/150 cranks to give the 150s a try on my G26.

I think it will be more accurate for improving the control/comfort/accelerations in 2nd gear. (but will be pretty weird in 1st gear).

The other thing I found hard to deal with was the camber.
In first gear this was not an issue (tyre: swchalbe super moto 26x2.35, 60PSI) but once in 2nd gear it was a pain in the ass to deal with road cambers, especially when it was associated with tight bends.

The more I think about it, the more I see myself putting this hub on my nimbus 29 road (with the modifications needed) in the future, with a Marathon Supreme 28x2.0 tyre (no road camber issue) installed tubeless and 150 cranks.

By the way, I think I have read that tholub was thinking (back in the past) about putting a suprem marathon in his 29er since the BA 2.0 was camber-sensitivity-free but MS was lighter.
Tholub: Did you put the SM in your g29?

Thank you guys for the advice.
v1 - 8.40pm: I have finally decided to go for the 117/137mm. I hope I’ll be able to crank these 137mm offroad in high gear, but let’s see. A bit concerned it will be tough to start with, but like anything else in unicycling, hopefully it will just get better and better with time! Worst case scenario: I’ll have to buy 127/150 later on…
Now the waiting really starts…:o

v2 - 8.45pm: argh! actually, come to think of it, I should remember that a geared up 26 will be 39, quite a bit larger than 36. That, plus the shorter cranks, the smaller wheel (hence not as good for rolling over small stuff) and I can anticipate not using the high gear much offroad with 137… I think I should go for the 150, hoping I can change gears with the ankle… (that remains my main concern for the 150 - not too keen on a DIY solution like UniDreamerFR’s - nice creativity though!).

Hopefully there will be no v3. :stuck_out_tongue:


I prefer 137’s on all my unicycles especially my 26" schlumpf.

Did you start guni with 137?

Without any knee pain issues and with much practice, I could finish by returning to the 137, but not for muni I guess.

Indeed 26" x (17/11)= 40,18"
and 29" x (17/11)=44,81 nearly 45"

Just received the Five Ten impact 2 High I ordered and should soon receive the 127/150 cranks.
If the Five ten are not enough to enable ankle shifting I’ll go with my DIY solution, it only takes 30 second to install and to remove, so it’s not a big deal.

I used to run 125s on my G24" with 3" Duro for technical XC Muni. I did find that it was a compromise I made to hit the speeds i wanted on easier firetrail, double track stuff at the cost of better DH technical control. When I upgraded to my 26" with 2.4" tyre I also changed to 137s. I found it go be a really good balance point- can spin nice and fast in high gear on firetrail, and also in low gear in technical single track. You still have enough leverage for technical DH (if you run a brake) and my size 42 feet are close enough to the shifting buttons that I can still hit fast shifts consistently for high speed singletrail riding.



I’ve always used 150/127’s and like the versatility. 150’s are great for climbing, technical, drops/gaps, mounting in high gear, riding super slow if necessary, and 127’s for DH and long flattish segments, and they still climb well enough in 1:1.

Just removed the 110/137 and put the 127/150.
Gave a 5min try on the street (150 hole) and wow!
I was able to accelerate so much easily, the control felt much better, and the pedal stroke needed to ride in 2n gear was also lower.
The shifting was also very easy (ankle), five ten impact high must have helped.

Can’t wait to give it a real test ride.

That’s good to hear… feeling better and better about my 127/150 choice. I also wear 5/10 impact high, so I am really pleased to see that you find shifting to work well.
But now I saw on fb some more minor tweaks are needed to the hub before they get shipped… hopefully not too long from now - I was hoping everything was already frozen and the hubs in their final specs were being built for imminent shipment :frowning:


Hey, I’ve been using the search function without any success so far.

I’m looking for pics or videos of kris holm using his g26, I’m especially interested in the setting (handlebar, cranks, tyre) he uses which, if I’m not wrong, is close to what terry uses.

Speaking of terry: will follow with interest your experiments with the knard 3" on your geared wheel.
Is there a review of this combo in the pipeline?