Freewheel Unicycling Megathread

So Mad4One gave us all a nice Christmas present with the formal announcement of their forthcoming switchable ISIS freewheel hub.

Riding video showing shifting here

I’ve updated the hubs section of this thread to include the new information.


@muni_ben has also now had a go on the Mad4One Hub:

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One of my wishes to the universe for this new year @MAD4ONE is, that it will be possible to lock the shifting mechanism, so that one can’t shift accidentally while riding. :pray:

But riding over difficult terrain with fixed wheel, that might unexpectedly turn into a freewheel, sounds quite dangerous to me. :warning:

Riding over difficult terrain with a freewheel, which might suddenly turn into a fixed wheel, is probably less dangerous.

I’d love to have a shifting freewheel that I can shift by hand and can’t accidentally shift by foot!


You can apparently remove the shift buttons so it can only be shifted by hand. I imagine you can also adjust them to be close to impossible to shift with your feet.


You could probably remove the buttons so that you won’t accidentally shift :upside_down_face:

A French engineer is working on a geared/freewheel hub that could be shifted by hand - see here (in French). Maybe his open source solution could be adapted to a single speed fixed/freewheel shiftable hub.

@mowcius do you want me to make the 4 first posts wikis so anyone can add their own resources and information?

I thought about a wiki, but I suppose I have the normal concerns around maintaining standards and consistency.
Long term perhaps a restructure and a wiki makes sense, or just some notes around the potential out-of-dateness of the information provided. For now I think I’d rather keep it as is.


Last year I sent a broad idea and some parts to roger UDC to add a Bluetooth (compatible with voice assistants) shifter to a Schlumpf hub, but I don’t think he spent time on that. It was related to removing the motherboard and redesigning the attuator of a Adaprox Finger Bot

Does something like the finger bot have enough actuation force to shift a Schlumpf?
And where would you put it so that you don’t bash your shins on it?

The idea was to insert motherboard inside an hollow crank like Onza/KH than tear a small hole inside the ISIS interface of crank to have the attuator reach out the crank. Than match it with a small side cut in the ISIS axle to get the actuator touch the inner Schlumpf shaft. Repeat on the other side.
Cons: damaging axle structural integrity

Better idea was to sent parts to a unicycle developer/creator like Roger and hope he’ll get in touch with someone who can redesing the actuator/idea to fit directly into the hub

There are plenty of things that I don’t want to be voice activated, shifters are pretty far up on that list…

I’m very curious on how similar the Mad4one clutch mechanism is to the schlumpf hub, getting reliable and quick engagement that works in both directions with very little play is quite a task. (I’d certainly take a close look at Schlumpf hubs again if I had been given the task to design one).

When I had thought about freewheel hubs, I’ve always thought that there probably are relatively simple ways adapt one, so that you can insert a bolt (or a few ones, to be safe) to switch between the modes. Would be a pretty cheap solution, not exactly a “side of the trail” adjustment, but better than carrying around two wheelsets.

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Adaptation wise I suspect not - there’s not a lot of hub surface on the sides to do anything with, and not a lot of space between the frame and the hub flange in which to lock something to the axle and the hub shell.

I’m not even convinced that it’s a trivial thing to do on a new hub design owing to how little width you’ve actually got between the bearings in which to fit a disk, the two flanges, and some kind of strong locking mechanism. On large wheels we’re already stretching how narrow the flange distance should be on 100mm hubs.

I imagine that the mechanism employed on the Mad4One hub has many similarities to the Schlumpf design as it’s been well tested and proven over more than a decade, and the patent has expired. The whole purpose of patents expiring is to ensure that they don’t forever stifle innovation. I don’t think there are many ways you can do shifting on a unicycle while in motion, so it’s nice that this one is now available for everyone to freely experiment with.


1st day with my new freewheel! bicymple hub


Just posted on YouTube – Mad4One prototype freewheel test… :slight_smile:


So, how is it @turtle? (That’s Markus, right?)
Is the freewheel/fixed shift easy to do? Does this look sturdy? Is it heavy? Any idea of the final price? :innocent:

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We were able to test the hub very well in technical terrain. I rode it myself too. It is extremely robust, of course heavier then a standard hub and technically a masterpiece. It is quite similar to a Schlumpfnabe. Shifting needs practice (but I also wonder if it’s important to shift while riding). The costs will be adjusted to the complex production. mad4one will publish all the exact informations such as price, weight, etc. in a couple days.


@MAD4ONE just sent out an announcement if you are on the the mailing list. I will share the basics here. There are different prices when ordered as part of a wheel or a complete Uni.

STANDARD PRICE will be: EUR 1’184,00 + your country’s VAT.

The Mad4One Flick Flock Standard ISIS Hub consists of:

  • outer shell made of two pieces of aluminum ERGAL AL-7075-T6, in black anodized
  • axle and all internal mechanisms (consisting of 15 components) made of hardened steel
  • bearing diameter 42 mm
  • bearing spacing 100 mm
  • bearing width 12 mm
  • with standard 6 bolt mounting holes for disk brake
  • Freewheel made of 6 pawls and 30 clicks
  • Fully removable hub internals for cleaning and maintenance without having to take off the spokes.

Weight: approx. 1,200 kg. (we will give the exact weight as soon as we receive the final version).


100 € per 100 g you are kidding.

We opened a presale campaign with interesting options.
Here are all the details.

For any question, do not hesitate to write to me.


Thus the announced regular price is about 1400€ for this fixable freewheel hub (incl. 20% VAT). :moneybag::moneybag::moneybag:

Nice. One can build multiple wheels for that price or up to a dozen other freewheel hubs. :smiley: