not sure if she uses these forums… but shes my friend on facebook and just posted this. never seen any geared hub like it before. it’s 1:1.75
she’s on the forum, also jogi who built this!
it’s pretty amazing. bout a 50" equiv wheel right? i’d love to have it on a 36" 
I’d like to see someone ride with the cranks at the shortest length.
I like the way the “torque arm” is a tab clamped between the halves of the bearing holder. Just as easy to remove the wheel as on a Schlumpf but not reliant on just the right tightness of the bearing holder to grip it. Nice idea.
So is this the replacement for the 2.5:1 monster we saw a Unicon XIV then? It looks nice, but somehow the old one had more of a “Frankenstein’s lab” look that was really cool (steampunk I suppose it could be called). The new one just looks nicely made and functional.
Rob
Is this hub on the market? Can it be bought or ordered? I didn’t know there was an alternative to the Schlumpf. What might this one cost I wonder.
It’s not shiftable on the fly.
corbin
Is it shiftable at all?
At first I thought they were just drilled for weight, but my golly they are threaded huh…
Not from the looks of it*, so you’ll have to wait 20 years before it becomes trendy to ride.
I think there are advantages to fixed ratio geared hubs though. Especially if they can be made with a higher durability to price ratio.
*Edit: Though I suppose since it is built so that all of the gears can be removed from the hub, if one manufactured a different set the hub could be rebuilt with a different ratio. Would be prohibitively labor intensive though.
interested by something: how does this behave when it comes to dirt?
can dirt/small gravels/water get in the way?
thanks
from the look of that being open, I’m sure it wouldn’t take too well to dirt, could you imagine what would happen if you got a small pebble to lodge in there just right O.o you’d fly . . .
I really like the idea of a fixed geared hub, I think it would almost be mandatory to have a brake though.
I’m wondering about the wheel build, it looks like a particularly funky spoke pattern, I wonder how well that holds up, should be fine for the road I’m guessing.
I can definitely see having multiple fixed geared hubs of various ratios available within the next 5-10 years. It would be pretty sweet to have a choice between 1:1.25, 1.5, 1.75, 2 even. You wouldn’t be able to change gears, but you could up the speed to where you felt comfortable. The only real disadvantage is that it would make the mount harder, especially trying to mount a high geared 36er. but with 165 cranks, I think it could be done. People seem fine with mounting a non-geared 36er with 114s
There are a ton of forum posts on geared hubs, I think the unicycle community is calling out for a cheaper alternative to the shlumpf, something perhaps more reliable as well. The demand is definitely getting there.
I still need to ride a geared uni : ( I can only dream right now.
from the look of that being open, I’m sure it wouldn’t take too well to dirt, could you imagine what would happen if you got a small pebble to lodge in there just right O.o you’d fly . . .
I really like the idea of a fixed geared hub, I think it would almost be mandatory to have a brake though.
I’m wondering about the wheel build, it looks like a particularly funky spoke pattern, I wonder how well that holds up, should be fine for the road I’m guessing.
I can definitely see having multiple fixed geared hubs of various ratios available within the next 5-10 years. It would be pretty sweet to have a choice between 1:1.25, 1.5, 1.75, 2 even. You wouldn’t be able to change gears, but you could up the speed to where you felt comfortable. The only real disadvantage is that it would make the mount harder, especially trying to mount a high geared 36er. but with 165 cranks, I think it could be done. People seem fine with mounting a non-geared 36er with 114s
There are a ton of forum posts on geared hubs, I think the unicycle community is calling out for a cheaper alternative to the shlumpf, something perhaps more reliable as well. The demand is definitely getting there.
I still need to ride a geared uni : ( I can only dream right now.
(Not quite on topic, but…)
If you just want to play around with the feel of a (single) geared unicycle without costing big money, it’s relatively easy to build a small “penguin” giraffe out of the back end of a BMX frame or some similar small bike. Of course, you end up with a small wheel if you want to keep the pedal height down, and it’s not quite the same as a geared hub, but you do get to mess about with gear ratios easily and cheaply.
Back on topic, I agree that thing could probably do with a cover over the gears to avoid gravel-induced carnage. But then it wouldn’t look so cool. Perhaps a clear plastic cover?
Did yogi build it from scratch (lots of machining) or did it use a fair amount of already-available parts - is it possible to buy epicyclic gear parts “off the shelf”? I’m quite envious of people with the skill (and facilities) to build stuff like this.
Rob
No its not this 2.5:1 type, http://www.unicyclist.com/forums/album.php?albumid=42&pictureid=221there we need a new hub, the old one is brocken at the crank square - (not an issue of the gear) I will replace it by an ISIS hub - some day 
its just a new 1.75:1 not shiftable test gear.
We have to change one detail, may be more after testing, and the next step will be to test a shift version or to build some of this. Since the focus is in road racing i think there is not absolute a need of shift it.
if there is interest i can produce a few of them, at all, they would be cheaper than Schlumpf but will need more maintainace and less durable - or otherwise more expensive. If you like to order 1000 gears you will get a lower price and same quality:p but I think if you order 1000 Schlumpf gears it will be the same:p
There is no problem to house it, but most people like the visible mechanic.
This is a non comercial unicycling development project at the moment so feel free to copy to grade up or what else.
Sorry to seem a bit stupid…but I am stuggling to work out in my head how this even works to make it go faster, from what I can see it looks as if it would make it slower (maybe I’m interpretting the picture wrong…)
actually nvm, i have no idea how the thing works. now that i look closely it does look like a low gear haha
The gear in the middle (the “sun” of the epicyclic set) is fixed to the frame and stays still. The pedals turn the spider that carries the little “planet” gears. These little gears orbit the fixed sun, which they are meshed with, and therefore rotate as they orbit. For every rotation of the pedals (“orbit” of the planet gears) the outside edge of the planet gears travels the length of the orbit plus the circumference of the sun gear. This outside edge is what is meshed with the outside “ring” gear, which is what is attached to the wheel. So, depending on the relative sizes of the sun, planets and ring, various ratios can be created, but all geared up.
To gear down with an epicyclic gear, you have to hold the sun (or ring) still, drive the ring (or sun) and take the output from the planet carrier.
I hope that makes sense… it’s easier to imagine than to explain!
Rob
think of the outside ring as an anchor, it doesn’t move.
You’re powering the small rings around the center, and the center drives the wheel.
so if you spin once around, your small powered geared (the ones you turn) travel enough distance to cover the outside ring, and are transferring that to the inside gear, which has less teeth, and thus, must travel farther around to cover the same circumference as the outside ring.
one of us is confused ; P . . .