Hello everybody,
I am still selling my giant wheel Semcycle which was custommade for me by Sem Abrahams sr.
Never rode the thing, because in the end I was too cowardly. So it just stood there in the basement.
The diameter is 50 inch, which translates to 1,25 meters. On one of the pictures I layed a yardstick on top of it. It’s hard to see the numbers on it, but every rivet is 20 cm (about 8 inches).
Cranks are 125mm (about 5 inch) in length.
The wheel has 56 spokes and no spokesperson.
The saddle and the set of pedals Sattel are included.
→ Important: It’s a solid rubber wheel, not an air tyre.
I paid 800 Euro (even without the saddle and the pedals) when I collected it in the Netherlands. I’m offering it up for 550 Euro today. It it too cumbersome to ship it, so it’s only for collection at residence (Königswinter, near Bonn, both of which are in Germany).
If you are interested, contact me via email under HansNotzem@gmx.net as I do not come here often.
Is it a solid rubber tyre?
Yes, exactly. That’s what I meant when I wrote “solid rubber wheel”. [Not being a native speaker in English I had to go with what the AI told me…]
Where do you get the replacement tyre or is it a custom part maybe from wheelchair tyres joined together?
It is a good question. I have so far not used the cycle ever, so logically I didn’t have to replace the tyre yet. It seems to be custommade bei Sem Abrahams from one piece as there is only one lap joint (if that’s the right word; I might have said “seam”, but it is not really that, just a very thin line—hardly detectable—where the ends meet edge to edge). A wheelchair tyre would not be big enough, and it’s definitively not made from two parts. I guess Sem Abrahams had a supplier for getting tyre by the running metre.
Half tempted to get a passport and book a flight to Germany. 
I would love to own (or at least try) a mega-uni some day… 
Alas, I am a U.S. based, meaning this one is out of reach.
If I ever have a boatload of money fall from the sky, I’ll probably have one built for myself… Likely with the addition of a brake of course 
Makes sense, on such a big wheel. Thanks to the kind of tyre you could go with a Penny Farthing type brake; for style .
I would strip off the frame and turn it into a UW, but you’d already expected that no doubt 
I don’t think the tire would add much comfort.
I’m not surprised . Sure you would be able to even mount such a beast? I mean, you almost need a ladder…
about 15cm higher, but I don’t think it matters so much. When holding on to something when mounting, I would already be on top and with the same “crank length”, I don’t expect to notice much difference. Hopping off the front will just be a bit further down. My knees won’t like that.
Nevertheless, I am already looking forward to my new BC wheel, which I expect any day now. So unfortunately I am less interested in this uni.
If I ever have a boatload of money fall from the sky, I’d probably build a second garage to keep the cycle in… or—more likely—give it away for free to a local children’s circus project or some such.
A brake would be nice, agreed, but maybe it could still be added? I am no engineer/tinkerer, so I would not try it myself, but it should be possible.
Mounting solid tires is rather interesting. You cut the tire which is a tube to lenght then run wires through it. Then there is a special tool that pulls the rubber apart and a different tool that pulls the wire tight and then twists the ends together. The you remove the first tool which allows the tire to spring back together. There is a video but I can’t find it. Engals Coach Shop might have one.
Not the one I was looking for, but still: https://www.youtube.com/watch?v=EPbFIhv3iFg
Why have you never used it??
Sorry, I see you said you were too cowardly. But I assume you must have at least tried to ride it - you had it made for you, after all! I feel like there is a deeper story here - of dreams fulfilled and reality throwing a wet blanket… I would love to hear more about your relationship with this machine. If you feel like sharing 
No big story, actually. A few weeks before I picked up the cycle I had a fall into a pit—I wasn’t even riding a unicycle when that happened, but only helping a friend move house—and when my leg had healed I eschewed my higher cycles. I did ride my 6-foot giraffe again, as I always felt secure and in control on it. But I never again rode my 8-foot giraffe (which I will eventually offer up here, too). And even though this giant wheel is not very high, I figured that I would probably only learn riding it if I were willing to go thru some, uh, involuntary dismounts. I thus kept postponing my first ride on it time and time again, I didn’ want to risk another injury. And now that I have practically stopped riding unicycles altogether—nothing psychological, just old age—I try to empty out the basement and the garage. Let me know, if you wanna help me with that…
I finnaly found the Engals coach Shop video. this is reduntant information but some one on this forum may want to build their own equipment. Again it is possible to do this with hand tools and twisting rather than welding. If you put rubbed in compression it makes it harder to cut but it also makes it slicker. It is quite an art to do this. https://www.youtube.com/watch?v=sldK65_HUgc