Florian Schlumpf in Seattle

We had the honor of hosting Florian Schlumpf, the Swiss engineer and designer from Schlumpf Industries today in Seattle. We met at the University of Washington at Red Square, a large, open, public area. From the links to photos and footage that will follow (I myself have 500MB to process which will take some time, I’m afraid) you will see that we had twenty or more riders show up at this gathering. Florian has made a production model shiftable unicycle with an epicyclic hub and a 24" wheel that can be shifted from 24" to 36" equivalent.

First, let me say that this is the most incedible piece of unicycling machinery I have ever seen. It exhibits unbelievable craftsmanship and has silky smooth operation. Not only is it POSSIBLE to shift this unicycle on the fly, it’s surprisingly easy. Irene Genelin, Bruce Dawson, and I all shifted both up and down on our first tries. I don’t even think Irene knew how it worked and we explained it to her while she was riding. She was the first one to shift it on the fly and that was on her first ride. Tom Jackson, Abram, Jeff Sloan and a number of others shifted this unicycle on the fly but not necessarily on the first try.

The shifting highlight has to be when Irene was seat dragging Florian’s unicycle in 24" mode and hand shifted to 36" mode. When the gears caught, the gear train snapped the frame up and the saddle smacked her on the butt. I spent alot of time trying to get footage of that.

The other geared unicycles in attendance were Pete Peron’s Purple Phaze and my BlueShift. Pete’s geared Coker has been written up recently but I don’t think it has since he changed the gear ratio to 1.89:1. Yes, you read that correctly; a Coker geared up 1.89:1. About a 70" equivalent wheel diameter. We have photos and footage of all three builders on their respective unicycles riding together. It was an incredible, sunny, adventurous, and beautiful afternoon.

Photos and video will follow as will the writeups of others.

Here is the photo of the three builders. From left to right, Florian Schlumpf with his production, shift-on-the-fly 1.5:1 24", Greg Harper with his stationary shift 1.5:1 29", and Pete Peron with Purple Phaze a fixed 1.89:1 36" wheel.


And here are the three riders on their respective steeds:

It looks like the three of you are getting geared up for a shift in distance unicycles.

Wow, great pictures, for the history books.

Imagine, someday people may never know of the struggle of non-geared uni’s.

This is the future or touring unicycles!

By all means buy one of Florian’s geared hubs! They are truly incredible!

I just swung thru my office so I could use my high speed access to upload my pics.

They are in:


Un-editted & uncaptioned at this point, feel free to leave comments.

Quite a good time with the Schlumpf 24, Blue Shift, Purple Phaze, many Cokers and a 29er with 110’s. It was really interesting making the adjustements from uni to uni.


I have added 10 .mpegs to Steve DeKoekkoek’s gallery. I tried to pick out ones of interest. Especially the sequences of Bruce Dawson when I’m doing foot shots of him shifting Florian’s unicycle. Others include first rides on particular geared unicycles or rides where multiple geared unicycles cross paths. Finally, of course, Irenes seat drag hand shift. I had to include Abram’s ride although it wasn’t a particularly good video because he was partially resposible for organizing the meet. Finally, Tom Blackwood crossing the geared unicycle barrier that has plagued him for a year deserved attention.

I, of course, broke someone elses unicycle today as is my want recently. I did a three step jump down on Bryan’s Torker DX and snapped the axle off at the right crank. I felt obligated to loan him my Coker until he gets a replacement wheelset.

KOOL can you post the url or sometin

Thank you guys for posting the photos and especially the videos - they’re great. Congratulations to all who rode and shifted. I knew it wouldn’t be impossible to shift on the fly. Irene - you rock!


That’s really interesting, especially Irene’s seat drag. I would love to try coasting on the Schlumpf unicycle. It should be easy to coast at Coker-type speeds, and unlike on the Coker, there would be something solid and relatively low to rest your feet on. Has anyone tried that yet?

That’s awesome. I think those are the only three geared up nongiraffe designs I know of, and they were all at the same place at the same time.

So, how did the three compare? Which was the smoothest? Which was the fastest? I want all the details.


Today was my first day riding a geared uni, and since I had successful rides on all three, I’ll offer my view. Hopefully others will respond as well.

The Schlumph 24 was the easiest to mount and ride, hands down. Pete’s 36, geared at almost 2 to 1 ratio, was the hardest…again hands down.

For ME today, Blueshift was the fastest, but that’s because I got to the point of being comfortable, so I pushed it a little bit. It’s the same ratio as the Schlumph, but with a bigger tire, so it’s bound to be faster. Pete’s by design would be the fastest, but I never got comfortable enough to push it. Riding Purple Phaze for me was…well, I was happy just staying on for a while and surviving. I’d need some time and a long straight trail to get comfy.

In terms of smoothness, harder to say…they all rode a bit differently. In terms of “play” it seemed like Pete’s 36 had the least, followed by the 24, followed by Blueshift. But they were all close. With Blueshift, it still had a definite “flywheel” feel to it, which I like, but didn’t notice on the 24. Frankly, on the 24 it was easy to forget it was geared after awhile, until you noticed how fast you were going for relatively slow pedaling. On the two larger wheeled unis, it was impossible for me to forget they were geared. Lots of mental energy needed!

If I was going to own a geared uni, it would be with a 29" wheel or bigger. Not too big to freemount easily, but big enough to get beyond the 36" effective wheel size of the Coker.

BTW, I’ve added my shots from today to Unibrier’s gallery. Tried to just include ones that hadn’t been already posted. I think my fave might be this one of Steve on a Coker trying to keep up with JC on a shifted 29.

img_2225 sized.bmp (900 KB)

Frank Bonsch’s 1.67:1 28" unicycle was missing from the bunch. I think Frank lives in Achen right now.

There is no question that Pete’s Purple Phaze is by phar the phastest if you can control it. I think Florian’s shiftable unicycle was the smoothest operating of the three and had backlash comparable to that of BlueShift but it wasn’t as noticeable while riding it in my opinion.

But you didn’t ask which was prettiest.

I had never rode a Coker before today. After freemounting a Coker I rode Blue Shift, this was realy cool but there was a lot of play. I sort of got used to it after a while.

Then I rode Florian’s and was able to shift it. It’s really quite easy to shift while riding, you just drag your heal over the crank and eventually it shifts and almost throws you. It does have play though, I heard something about 1mm of play at the ends of the cranks but it seemed like there was more than this. Even in 1:1 there is a fair amount of play. I found that at 1:1.5, effective 36", it was more manuverable than the Coker. The smaller, lighter wheel has less angular momentum making in more manuverable.

After that I got comfortable with these two Pete helped me mount Purple Phase. This uni is very hard to ride at 70" effective. I did ok after like 8 tries. The nice thing about it is there is no slop at all and the chain tension doesn’t cause very much resistence. He has really long (180mm?) cranks on it which are necesary. There were quite a few jokes about Pete being super human for riding it till a few other people managed to.

So PP is definitely the fastest and the smoothest and the hardest to ride. Florian’s is the most versitile and available.


Re: Florian Schlumpf in Seattle

On Mon, 14 Feb 2005 07:27:18 GMT,
klaasbil_remove_the_spamkiller_@xs4all.nl (Klaas Bil) wrote:

>Thanks a lot for these posts, folks. It’s good to read and see that
>Florian’s unicycle is such a fine piece of craftmanship, so easily
>rideable and even really shiftable on the fly by mere mortals.
>Also, with the three geared unicycles it was a historic event. Pity
>that Frank Bonsch didn’t attend the party, then it would have covered
>all the geared uni builders the world knows of (I think).

Hi Greg and Klaas!

That´s really what i felt when I saw the pictures and watched the
videos. Also seeing Irene seatdragging. I met her at 1999´s Ride
across Minnesota.

I will try to set a new personal best for marathon distance on June,
19th at the ‘Mittelrheinmarathon’. That´s a 42km-marathon along the
river rhine so with no hills and no turns, ideal for high speed
unicycling. The organisers agreed that i join the handbike/wheelchair
group (there are no other unicyclists). I’ll try to break the 1h:40min

CU sometimes!


Of further interest here, Florian began unicycling about 25 years ago and did it for a short time only; maybe a year or two. He picked it back up when he started working on his production geared model. He was riding a geared unicycle in the photos shown in this thread essentially in Birkenstocks or some equivalent sandle. He didn’t intend to ride when he showed up.

if that was indeed a DX i want to see a pic of that…

I added a video to the gallery (Bruce riding Purple Phaze) and some additional pictures.