Pondering on a Schlumpf - questions

There’s a distinct possibility of me breaking my new years resolution of buying another unicycle. I bought a 24" muni last year, a 6ft giraffe the year before, and a 20" freestyle in 2003.

I think my next venture will be some kind of 29er for long pavements and roads, and let’s be honest… I want to go for broke and get a Schlumf geared uni.

First question (possibly stupid): is it possible to idle and ride it backwards? I’m thinking if I need to idle it in case of sudden obstructions ahead, somehow my mind says it may not be possible with geared mechanisms.

Second question: as seen in this picture the hub clearly says “please read instructions carefully, especially for off-road and free-riding”. What exactly are the issues when it comes to off-road riding? Smooth-ish gravel tracks will be the roughest terrain I plan to ride it on, so I’m more curious that worried.

Third question: what size cranks do you recommend? I’m so used to the 150mm cranks on my 24" muni that the 127mm ones on my freestyle feel so twiddly and small for my extra long legs (34"-35" inseam). I was thinking about 140mm but that doesn’t seem to be an option on unicycle.uk.com, so it’s gonna have to be 127mm or 152mm…

I’d wait for the splined version coming out later this year.

You can do all that and anything else you could do on a non-geared uni. There will just be a little backlash that you may feel.

I can find the manual, but I think it just spells out that it’s not exactly a muni and off-road use requires a little TLC. On the Laos Unitour, Florian mentioned (jokingly?) it’s not warrentied for any drop larger than 3 meters as we were looking down a cliff.

I have 125 mm cranks and they are the best for long distance in my opinion. But this is not an opinion shared by all. On the Laos tour, only Ken Looi and I had cranks this short. I think most others had somewhere around 165mm. So, I’d recommend going with as short of cranks that you are comfortable riding with. You can start longer and change them to shorter once you get proficient at riding the uni.

And no, you don’t have to wait for the splined one if you are doing long distance riding or communting.

Is that a reference to its price? It’s not that much, really – a lot cheaper than taking public transportation or driving (and paying for petrol and parking). That’s my excuse!

There are no stupid questions, only stupid people who ask questions that everyone else knows the answer to.

Kidding aside, yes, you can ride it just as a regular uni. Proviso: In high gear, it’s really hard to ride backwards or to idle. Since you mention that you’re not going to be ‘off-roading’ a lot, I’d go for the less expensive guni that’s available now rather than waiting for the uber-hub coming out this summer. But if you foresee lots of curbs (kerbs, I mean) in your future, or other slight drops, perhaps it’d be best to wait.

It depends on your skill. If you are a really good rider, you could get used to the speedier 127s. I am glad I have them. If your riding will include lots of stoplights and other slowdowns, I’d consider longer cranks. Also, if you don’t like going fast, definitely get the 152s for the greater control. If you are used to going quickly, get the smaller cranks. It’s going to take you quite some time to feel comfortable riding in high gear on 127s, but for me it was worth it.

If you have lots of uphills in your future, either get the 127s and plan to downshift a lot, or get the 152s and leave it in high gear when possible.

The hub says that on it, but the instructions don’t say anything about off road and free-riding. Roger sold mine to me for using in a mountain bike race (xc, without drops), so I guess it’s okay as long as you’re not doing drops.

They do sell 140mm cranks for it according to schlumpf.ch, so I’m sure Roger from unicycle.com can get hold of them.

I’ve got one, and I’d say that it really might be worth waiting for the KH one. Not because of the hub, you probably don’t need a splined hub for what you’re talking about, but for the frame. I think the new hub comes with a cunning torque lever attachment so that you can use a standard and well tested KH frame, rather than having to use the Schlumpf frame.

From the brief amount of riding I’ve been able to do on it, I’m happy with the hub, but the frame was poo. It broke after five hours riding. Snapped through. According to Schlumpf, I think it’s because the instructions didn’t tell you that you need to torque up the 8 bolts to adjust the seatpost exactly right or something. In the case that you don’t, the very thin braces holding the seatpost can snap right through. I’d not trust it for any long ride, unless you ride with a support crew, you really need to be confident that you’re not going to be left unable to ride 50 miles away from home, that could be one expensive taxi ride.

Even without that, the frame is rubbish for several reasons. Firstly, there are 8 bolts you need to undo to adjust the seatpost. Which all have to be tightened up exactly right or else it’ll spontaneously snap after a few hours riding. Secondly it’s a very tall frame, I’m normal sized (5ft 10) and I was hitting the frame sometimes on mounts, it’s about 4 inches taller than a Nimbus 29" frame. I’m currently still waiting for a replacement frame, which hopefully will be different to avoid these issues, but I’ve not been able to ride mine for about four months now.

From my riding, it’s easy to idle in slow mode and okay in fast mode, kind of like idling a coker, except with a little bit of backlash each time you idle, kind of like when the cranks are loose on a normal uni. You can ride it backwards just fine.

Cranks wise, I’d suggest start off with something like 150s, if you’re not used to riding a big wheel with short cranks already.


I never knew that. My frame came direct from Florian, assembled minus the pedals. The post included was too long and had to be cut down, but afterwards I was good to go. I have ridden 650 miles so far, 90 in one day, and have not heard of others having frame problems other than the size. I know that many riders on the Laos tour had Schlumpfs including Ken Looi, who has also ridden his quite far.

I don’t think I follow your meaning. I have a few more bolts than usual on the seat itself, but the post goes into the frame and is held there by a round sleeve with two bolts. Loosen those, and you can move the seat post up and down.

Yeah, it’s annoying that the frame was so high, but I guess that was in order to accomodate certain tire types. It’s a drag, tho, that the 1st and 2nd generation hubs can only be used with the Schlumpf frame owing to the way the hub works.

You (and I) have the first generation aluminum frame. There was a sourcing/quality issue with these, so Schlumpf made a completely different frame, as seen in this photo:

Wow, Gilby. Thanks. That design is really different, and I can see why someone would be unhappy with it. I also notice that the part that holds the hub (at the bottom of the frame) is different, too.

Glad to see this conversation, it’s answering a few questions for me too. I am considering a Shlumph and have decided to wait for the KH splined version.

Mainly because I do easy trail (canal tow path) riding with a few shallow steps and sometimes end up with loose cranks after a few miles. Splined is just so much a better engineering solution to the problem than squeezing a taper in soft metal.

Also I must consider that one day I might be somewhere I want to take it off road or can’t resist a few drops and I wouldn’t want to be worried about breaking several hundreds of pounds worth of uni, better eliminate that possibility and get the best I can afford first time round. This has proved true with my other unis, I started with low spec stuff and within months ended up making expensive upgrades.

I would like to know though, if anyone knows yet, will I be able to buy the hub and have it built into a setup I already own?


According to the big thread on the KH geared uni, the hub assembly and such will be most of the uni’s price, so you might as well buy the whole thing and get a cool frame and seat rather than save a couple hundred bucks (or pounds).

I don’t own a Schlumpf but I’ve ridden some, and I can at least respond to your first question. When in the geared mode, it will idle or go backward similar to a Coker. Which means you can idle, but it’s probably the last thing you would want to do in an urban situation when you encounter an obstacle. Of course the smaller wheel will make the idle take up a littl less space, but still idling is not necessarily the best option on a high-speed uni.

I never idle or go backwards on my Coker unless I’m specifically trying to, and I only do that when I have lots of space. When commuting or otherwise Cokering, If something gets in my way I’ll either go around, or stop. No problem. I guess that’s what I would do on a bike anyway.

This answered a lot of questions for me as well. I can’t blame you guys for not stress testing your really expensive unis, but if I can’t be rolling off/hopping up curbs I think I’ll wait for the kh hub and be able to do what I want with it, peace of mind intact.

Keep in mind that it’s been typical for the actual availablity date for any new unicycle to take longer than initially expected. Especially when dealing with small companies, in this case, both of which have high quality standards. If one thing is not right going into production, it could mean a few months delay. So, while it’d be great if late summer was when they’d be available, I wouldn’t bet on it.

Re: Pondering on a Schlumpf - questions

On Thu, 6 Apr 2006 12:35:43 -0500, johnfoss wrote:

>Of course the smaller wheel will make the
>idle take up a littl less space

The amplitude of the movement (the distance that you go to and fro) is
not so much related to wheel size but to crank position, I think. The
only reason the idle should take less space is that the smaller wheel
itself takes less space. However, the virtual wheel diameter of the
Schlumpf 29’er is about 45", significantly more than a 36" Coker. So
all in all, idling will probably take MORE space.

This is all theoretical since I can’t idle the Schlumpf in high gear.

OK, next question, aimed at those with experience of Cokers and geared unis. I have experience of neither.

The fact that a coker rolls so nicely is, I presume, mainly due to the weight of the wheel in motion (angular momentum I think is the technical term) combined with the size of the wheel. So small bumps etc get soaked up.

With a smaller wheel, geared up to an equivalent size, do you get the same effect? The wheel weighs less but is rotating faster so the momentum could be roughly the same, but the diameter is smaller so presumably it won’t roll over a bumpy surface quite as well as a large wheel.


That’s exactly right…The Schlumpf takes more concentration to ride, as small bumps tend to throw you off more, due to the smaller wheel and higher gear.

Small bumps get soaked up by a Coker (remember also that a Coker tyre is HUGE, even if it doesn’t look it). But more importantly it rolls over small irregularities due to the larger diameter. I reckon if you could get a Coker wheel to weigh the same or less than a Schlumpf wheel that it will still feel more stable.

It looks it

:smiley: What I meant was that it doesn’t look as big as something like a Gazzoloddi tyre would look on a 26" wheel, but I think it’s similar to my 26x2.6 Gazz Jnr because it is just as tight a fit on the hooks I use to hang the Unicycles up with. I think it’s bigger than the Big Apple in it’s crossection.

I thought that you can use any square taper cranks with the Schlumpf hub. (Someone correct me if I’m wrong). So this means that its the strength of square taper cranks vs splined cranks that you are really comparing. Most unicyclists are familiar with the issues here. Square taper cranks aren’t as strong, but they are certainly strong enough to do some hopping on and for a uni that will be ridden largely as a road machine, perfectly strong enough. Splined cranks are overkill (and not to mention heavier, too) for your purposes. Just get some strong square taper cranks and you’ll be fine with the standard Schlumpf hub.

Here’s a pic of me jumping over Ken on Florian’s 26" Schlumpf http://www.laosunitour.org/images/Day4/NathanDay4/Laos%20037.JPG

I think any square taper crank should work, provided that they leave enough room for the shifter button. Florians cranks are really nice though- they work great on non-geared hubs.

Splined cranks are really only heavier than non-splined cranks on unicycles because they are designed for trials use on unicycles. The splined cranks on my Road Bike are really light. Would be nice to have a full alloy splined crankset for road/XC Muni use- steel is overkill IMHO. And it rusts too.