Hi I built a geared uni using gear cogs salvaged out of an old self drive lawnmower.It involved major alterations and fabrication resuling in a 26" wheel geared up to mimic a 37" wheel.Unfortunately it didn’t work due to the massive torque forces twisted the frame until the gears lost mesh.Determined not to be defeated I refashioned the hub to run chain and sprocket type gearing and made an adjustable jackshaft to adjust the chains.This new setup also gives 37" gearing and is successful with a 10km ride completed.
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good work:)
Video or it didn’t happen 
thats awesome man!
i hope it hold up alright.
Chase
That is 1 awesome looking unicycle you have there my friend. Good work too also. 
Stunning… simply stunning.
Nice work!
!
That is too cool. Congratulations on making a successful geared uni.
I wonder if the second version would have ended up working if the frame was stiff enough?
Yes, VERY!
holy crap, nice work!
looks like you’re close to being able to run a derailleur for some gearing on the fly 
Too bad the initial gearing didn’t work out. I would still like to see a viable version of that implementation. The jack shaft design is a good one that has been thoroughly proven on Pete Perron’s three versions (also homemade) of the idea. The simplest and cheapest of the homemade jack shaft driven unicycles has to be Tyler’s but we haven’t had much of an update on it since his major axle modification.
You have the sprockets separated by quite a distance. Is that to give you as much room as possible to fit them between the spokes and the frame up towards the rim? The long chains probably add a bit of weight as well as increase the amount of backlash due to the extra chain links. It may not be possible for you to locate the sprockets down where the spokes flare out to the hub flange, though. Cool implementation. Did you do all the work yourself? About how many hours?
Guys that is awesome! Having been there, congrats on putting in the all the time and effort it takes to create a rolling work of metal art! Respect has been earned.
Hey man thats cool do use a front derailler off a bike or something?
would some kind of hydraulic deraileur work? i know a regular one wouldn’t because the spring tension is too low…
Very cool engineering project. Mind the pant legs!
I once rode something sort of similar, a reverse-drive unicycle built with cogs just above or below the axle. It rode like a two-wheeled unicycle, only on the ground. You could sense the friction in the gearing, but it was probably a lot less than the friction you get with a tire-friction two-wheeler.
Pictures? This was 1984 or so. Someday I’ll have to do a massive scanning project… 
thankyou all for your interest,and credit to all those before me who have designed or built geared uni’s.My interest came about from searching the internet ,Harpers geared hub, the shlumpf and others gave great inspiration.My initial design was my dream and worked well on the workshop bench and was a beautiful thing but didn’t work in practice.The chain drive was really just a salvage operation.I did all the work myself spending I guess about 200 hours and costing about 50 dollars.All the gear cogs ,rim ,spokes etc were recycled from old bikes.The position of the jackshaft was where the greatest clearance existed between the forks and wheel as initially I was going to use a modified freewheel but I came up with a much slimmer setup so I could lower the jackshaft to any position now.The build was very low tech mostly using angle grinder,electric arc welder,cheap drill press.The inside of the hub was skimmed on a friends lathe ,the shafts were built up with weld and taken down to size in my drill press with an angle grinder and file to suit the bearings.It is one gear only there is no scope for changing gear.
Pardon my ignorance on the whole geared uni thing but do you actually shift gears? If so, how? Or is it a permanent gearing ratio change? I think it is awesome especially Tyler N.'s “it’s done” video but I am still confused having never seen one in person.