I’m thinking…
Regarding the Sturmey hubs, it would be an interesting experiment, but if they’re anything like the old Sturmey 3-speed fixed hubs (the ASC) there is quite a bit of gear “slop”. Some bicyclists didn’t like it because it didn’t feel like a “proper” fixed wheel, so it may be too baggy for a nice riding unicycle. Although it may well be possible to get used to it and ignore it with practice. Better than a freewheeling unicycle at least!
Rob
What if instead of the buttons shifting through the hub and out the other side, if they were pressed and then poked back out? This could leave more options like having the left side be a low gear, and the right side a high gear. To go back to 1:1 you would simply hit the button again of the gear that you’re in.
Looks like you should by a Schlumpf! For your three points: Reliability – The issues with the earlier hubs have been worked out. Maintenance – planetary hubs are basically zero maintenance. Occasionally shoot some grease in a slot, and that is it. The chain on a bike requires more maintenance.
So 2 of your 3 conditions are met. Affordability is relative…
-corbin
Cool idea! I’ve always wanted to make something similar to this - part of the trouble is the how to do the derailer/clutch shifting without it causing too much slop, or freewheeling. I’ve had some ideas on how to do this.
corbin
Mmm, maybe when a year’s gone by and I don’t personally know multiple people waiting on their hubs to return from lovely holidays in Liechtenstein, I’ll bite. (Again, not disparaging the hub’s designers/makers - I recognize that it’s a brand-new invention solving a difficult problem.)
With respect to maintenance, what’s this I keep reading about people having to readjust shifter buttons, and use torque wrenches to tighten things to precisely X Nm?
Let me just chime in that, since I got it back from Florian, my hub has operated flawlessly even as I’ve (as far as I can tell) punished the crap out of it. It’s making a couple funny noises now, but after around 5,000 miles on it, it still works just fine aside from the noises. My bike has given me infinitely more trouble.
I had some issues keeping my crank buttons in the cranks, and my cranks on the spindles, in the very beginning, but after about the second month, it all settled in and I literally haven’t touched it since, other than to ride it. And I just bought my first torque wrench last week, and have never used it on my unicycle. 
Like the good Corbin, I say a Schlumpf hub is your ticket!
And BTW, count me in for ANY reliable three-speed drive train that:
A: goes higher than 1.5
B: won’t kill me if I try to shift it while riding
Even a two-speed drivetrain with a 1.67 or 1.75 gear ratio or something (which I very distinctly remember Florian saying he could make) would be fantastic. The shifting would be a huge, intense jump, but I’m sure we could get used to it and it’d be “worth it.” I figure if we’re capable of smoothly riding as slow as 5-7mph in 1.5:1, we’d be equally capable of smoothly riding as slow as 5.8 to 8.1mph at the same cadence in 1.75:1, to shift to the same 1:1 direct drive ratio as always. Such a setup would make the flats much faster and the downhills MUCH faster, but would definitely widen that dastardly range of grades where the high gear is too hard and the low gear is too easy. That’d be a trade I’d be willing to make, though, because 165mm cranks were never more attractive than in the face of a higher gear ratio!
sorry I haven’t draw up the rest of my plans, I’ve been busy with a research paper that is now late (yet here I am, lol).
after much consideration, the disengaged/dropped cassette is more complicated a solution than required. leaving a the cassette where it is, all that is required is a derailleur that keeps proper chain tension while engaged, regardless of chain direction.
a pretty simple solution is a derailleur that pushes on both sides of the chain, which locks into place at each gear. a quick fire shifting pod for positioning the derailleur could be used in conjunction with a lever that first lifts a row of teeth that lock the derailleur into it’s position, then collapses the derailleur to allow shifting. a nice bonus is that you are would never have to freewheel, and that the momentary chain slack while shifting seems really easy to guess, as the slack is directly controlled by your lever. the derailleur cage itself is an X, with a cog on each point, that is held taught with a spring that the lever fights. the entire derailleur cage can rest on a mechanism much like the front derailleur of a bike.
To contradict what I argued earlier in this thread, on further thought I would also love a Schlumpf with a larger high gear. I am still not bothered about ‘more gears’, mainly because I haven’t seen or imagined a plausible way of building/operating them effectively (i.e. only at most as awkward as a Schlumpf shift).
A 1:1.75 gear compared to a 1:1.5 is the same proportion as 150s are to 175mm cranks. So using 175s you could get the same torque as using 150s on a current Schlumpf for a given speed, but more efficiently for your legs (assuming bikes get it right). Which, as Chuck says, would also mean you could go for 165s in the middle of that range and go both faster and easier. Bonus 
Sam
Tak,
Here’s the thing: These threads pop up every year, and though I’ve only been a rider/poster for three years, I have heard from other riders who have been around for a long time and they also have seen many of these posts.
There is a viable geared hub available, it has some issues which hopefully we be addressed in time. The problems with gearing unis always come down to the same issues: weight, complexity/reliability, and cost.
Unis are simple, which makes them lightweight, reliable, and inexpensive.
When you add complexity, such as a geared hub, you also add weight, decrease reliability, and increase cost.
Riding unicycles is a fringe sport, there is very little money in this sport, so R & D is also fringe. I can appreciate the OP’s intentions, but this is hardly a new idea or a new thread.
Sure, I could avoid posting to the thread, but then the OP did ask for opinions.
I will someday own a Schlumph, but it will be when I have the money to “burn” and I have a backup wheel
You also asked if I am satisfied with my non geared 36er: Yeah, it’s fine, I just ride muni more often, so the 36er sits. If I had my druthers, I’d ride every day, but with a job, kids, home projects and such, I really have to pick my poison, so I ride muni 3-4x a week unless I’m skiing
Don’t be such a little bitch, I can state my opinion that the OP is dreaming the dream, esp if he’s a new rider just throwing out yet another geared uni post. Nothing wrong with dreaming, but lets see some product, otherwise it’s someone’s “unsubstantiated opinion”.
My pet peeve is people who think they no someone based simply on their postings 
Imagine a chain from the chain ring to a gear box above the wheel, and another chain from the gearbox down to a cog on the hub on the other side of the wheel. I would prefer belts, but this stuff is off the shelf. Now to fab a gearbox.
you will not “derail” chains with derailleurs and tensioners, so your drivetrain will be safe in both directions and while shifting, and the person is not displaced further above the wheel like on a penguin. Done.
I still reckon a multi-speed gearbox that is small, light, drives both ways in all gears, doesn’t have too much slack/backlash and is shiftable without losing drive would be pretty hard to come up with. Most bike geared hubs can only drive in one direction because they “cheat” by using roller clutches to avoid having to mesh and unmesh gears.
Single-speed jackshaft unicycles have of course been done, as I’m sure you know (Pete Perron’s are the highest-profile ones from a few years ago).
Given the gearbox would have to be bespoke, I’d suspect it would be just as costly as a Schlumpf. Somebody suggested using a NuVinci CVT gearbox on a jackshaft, but I think they asked NuVinci about driving in reverse and they suggested it wasn’t really meant to do that. And they weigh a silly amount! Although a CVT unicycle would be the holy grail of gearing systems - no nasty lurches on shifting.
Rob
http://www.youtube.com/watch?v=kJDCuXkJfoY
http://www.youtube.com/watch?v=SQ-oxRSMlGg&feature=related
Jogi made a nice planetary geared set up too! I think the red one is Pete’s…
Interesting idea. It will have some tradeoffs, of course, but it sounds like a plausible design. And you could have a real shifter to shift with, Sturmey-Archer style.
One nice thing about it is that it takes the gearbox out of the wheel center, so it’s not subject to drop forces like the Schlumpf. And you can service the gearbox without dismantling the wheel.
You should be able to implement it without a terrible weight penalty; gearbox+hub would probably be similar in weight to a Schlumpf, so you’d basically be adding the weight of two chains.
The biggest challenge will be managing the slop (chain slop will be added to gear slop) and devising a solid clutchless shifting mechanism. (You could also do CVT but that would add a weight penalty).
Personally I love these threads, no matter how far-fetched or impractical the idea. That this forum can provide a free space for anyone with any background to propose these kinds of ideas I think is a great service. Bringing people together from diverse backgrounds and experiences to talk about things they’re not experts in presents huge potential for innovation. Sure, most of the ideas will never see a prototype. But one day some average person will put up something that revolutionizes our sport. Well, maybe.
I find the gearbox concept very interesting. To bring some parts of ideas in this thread together: Do shaft drives take an efficiency hit compared to chains? What I’m wondering is how the play in a shaft drive compares to a chain, if slop is limiting in this setup it might be worth it?
one could pull up on the gear box to tension the chains.
Am I the only one who doesn’t care about weight so much as having a solid, reliable, multi-geared setup? I’d gladly put an extra 5-7 pounds on my uni for another two gears. Imagine: who will go faster over 100 miles of rolling terrain, a super light 15lb fixie bike with one (arguably too-high-for-the climbs) gear ratio, or a 25 lb road bike that’s stiff, responsive, and got plenty of gearing options despite its weight? Adding 10 pounds is only 5-7% off your climbing speed assuming you can get the gear ratio you want, and being stuck on a light fixie without the gears would be infinitely worse. I’d take the road bike any day of the week.
That said, I remember reading somewhere that chains become more efficient as the tension on them increases, so having some beefy chain tensioners (perhaps going in both directions?) in there really wouldn’t hurt.
Another thing that would be nice would be to have one chain on each side of the wheel: you’d add a bit of weight with the shaft(s) on either side of the gearbox reaching across the uni’s width, but it’d be well worth it as the uni would once again be more or less equally heavy on each side of the tire track. This would require longer chains to get the gearbox above/behind the wheel, behind the crown and seatpost, but I like the idea of the symmetry nonetheless. It’s just that the idea of constantly feeling like you’re riding on a cambered road (from a weirdly-weighted uni) isn’t very attractive.
Everyone aspires to be average believe it or not! I think that regardless of expert status or not, most everyone that posts here is genuinely interested and on topic. It’s a joy to talk shop with like minded folks! The general demeanor of the posters remains friendly and seems self regulated, self control is always best. I have a lot of respect for the info exchanged here and for the posters that made unicycling and related learning accessible to me in the first place.
Yes! I could even give a little on B. 
Agreed!
I agree, and I’m confident that they will be addressed. I’m just saying that they haven’t yet been addressed to my satisfaction.
Yeah, I appreciate that there isn’t a ton of money being invested in unicycle gearing research.
Ad hominem, Brute? However, I made no claim of "no"ing you, just pointed out that your statement was baseless at best, and employed a tactic shared by a huge mass of ignorant trollery.
Yes! I keep bugging him to do a production run, so I can put my money where my mouth is!
+1