Lunicycle to ultimate wheel

I recently picked up a Lunicycle off of Craiglist. It’s fun to ride it, but now that I can, I’m wondering about trying an ultimate wheel.

2 topics:

  1. Is riding the Lunicycle anywhere close to an ultimate wheel? Will my experience carry over or is the ultimate wheel quite different?

  2. Is it possible to convert the Lunicycle to an ultimate wheel? Can you screw in regular pedals instead of the leg guard pedals? I’ll give this a try; just wondering if anyone else has already tried.


With a lunicycle, you use your adductors to press your legs against the supports, that’s the main difference. The direct consequence is that it is much easier to ride for several minutes with a lunicycle than with an ultimate wheel (I can “play” unibasketball on my lunicycle) . What is an advantage with the lunicycle becomes a disadvantage with the ultimate wheel (the friction of the wheel on the calves…).

For a few months now, I have a 16" and a 20" lunicycle. The threads of the leg supports are different on the 2 and are smaller than those used for standard pedals. I don’t know why they did this…

I have a 28" ultimate wheel and I’d be curious to convert it into a lunicycle (I was hoping to be able to screw the leg supports in place of the pedals, but it’s not possible…).

@UniGeezer builds makes me want to, but I don’t have the time or the equipment to make such modifications.


I bought the 16" for the sole purpose of using the leg support pedals on larger wheels like a 29er and 36er. The threads from that 16-in Lunicycle are standard 9/16 threads, so I don’t know why yours are not.

The Lunicycle wheel is “not round” it has a strange elliptical shape that smooths out the acceleration of the “falling” pedal. If you get used to that, you won’t be able to SIF or ride an Ultimate wheel.

So, ride the lunatic for leg conditioning, but then “re-learn” the whole thing when you want to ride an ultimate wheel or SIF a unicycle. Or…not.

I bought a lunicycle a few years back from Inventist. After a few trials, one of the leg supports got loose. Then I noticed how small those screws are that hold it all together. It is a very weak construction. I had contacted Lunicycle and they sent me new leg supports for it, but because it still seemed like a bad construction, I didn’t want to try it anymore.
What I noticed from riding is, how far your legs are push apart, which feels like sitting on a big horse. I don’t remember if I had bought my 28" UW before or after. Probably before and found it was very hard to ride it. But at some point, I got the hang of the UW and could ride nearly a 100meters.
Eventually I had to stop riding the UW, because I got extreme pain in my right knee. Possibly, because all of the weight rests on my legs and I somehow twisted my knee. I still have this pain in my knee, even when walking. It is quite annoying having such an old body. I guess I should be happy that I can still ride normal unicycle without any leg aches.

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You put me in doubt, I did some checking this morning.

For the exact diameter of the thread, I find 13.8 mm on the 16" lunicycle and between 13.9 and 14.0 mm on the 20" lunicycle. I did some measurements on several bike pedals, I find between 14.1 and 14.2 mm.

On the other hand, as much as the 16" lunicycle has a 20 tpi pitch like a classic bike pedal (on the right), the 20" lunicycle has a 10 tpi pitch (on the left):

To tell the truth, I thought the 0.3 mm difference in thread diameter of the 16" lunicycle leg support was too big, I had not tried to screw it on either a crank or an UW.

So I just tried it.

It goes in easily and you have to force it at the end because the hole in my UW is not threaded all the way through. I didn’t manage to screw it all the way in, there’s 2-3mm of thread left. It should eventually go all the way in by screwing harder or tapping.

Then I tried to screw a standard pedal on the 16" lunicycle, it’s hard to start and hard to screw on but it seems to be possible. I stopped after 2-3 turns. I’m afraid it will crush the threads.

In any case, it’s not worth trying with the 20" lunicycle and its 10 tpi pitch.

Oh and I almost forgot, I can’t wait to test my new 28" lunicycle :grinning: