i reckon a 12" splined trials would be pretty neat. nice and light for hopping, a real bugger for going anywhere
Dude I bet a person could hop sif so high on that!
no i bet you couldint
thanks Harper, thats so much better now :D.
and no, you cant hop too high sif with it, i HIGHLY doubt it. the wheel would buckle, you’d bend both cranks in, and its extremely hard to stay still on cause of the small wheel and cranks. but you could give it a shot 
lol I did a nice SIF hop (about 28") on the 12" schwinn @ one of the LBS, but decided I better not land it considering the thing was brand new and I was pretty much the first ever rider on it!!
i`ve tried one of those… i can do a 360 unispin on it:D and i can hop 50cm on it:D its really cool 
Imagine wheel walkiing that!! haha…
Ed
haha… imagine wheel walking on that!!
lol…
Ed
Is there a 12 inch rim with enough spoke holes?
hmmmm, probably not, you’d have to machine a wide one so it will take more spokes.
that would be kinda cool if you made it into an ultamate wheel:)
It looks like a doube stack type dealy. The chain goes off camera to the right to another wheel, I would imagine, that would be pressing against the bottom wheel. So you’d have to pedal backwards and you’d have 3 wheels turning at once.
New on here so Hi to All.
Trawling up an old thread but I thought it better than starting a new one, here's my "Puny cycle", I made it a couple of years ago from scrap bits & pieces (except the old Pashley saddle), since been painted so I shall get a newer photo.
Electric scooter wheel, tyre diameter 7", cut up & welded scooter fork & MTB seat tube/BB, driven by a toothed belt & gears (car engine cam/crank gear & belt).
wow that looks so fun, except the seat… they aren’t nice lol.
yeah i made a 8 inch uni out of tricycle too,
its pretty fun but its crap to ride anwhere.
some of these tiny uni’s are sick.
Can you actually ride them with any balance or is it near impossible? I’ve been trying to figure out how to put a harder gear on a uni without using a geared hub or making it into and giraffe and I think these ‘puni’s’ have given me the idea.
Something along the lines of a curved tank track? Maybe I’ll do a couple of drawings and see what I come up with!
Yep, I can ride my “Puny cycle” but it’s very low geared, couple that with the fact it’s made with 170mm bike cranks make for a lot of thrashing & very little pogress!
That could all be changed with better design, mine was made for fun from bits I had laying around so I wasn’t too picky.
The belt drive is geared 1 rev crank to 2 revs wheel so with the 7.5" dia wheel (7" sat on it!) it’s about the same as peddling a 14" diameter wheel. With the 170cranks the pedals are about 14" apart also!
If your looking for a single higher/lower gear, my first thought would be simple meshing gears as found in many simple old gearboxes, mangles, boat/trailer winches, that kind of thing. Obviously it would involve quite a lot of work making the frame.
Here are a couple of ideas I had. They are only very quickly sketched just to get an idea of what they might look like.
