All this talk about geared unicycles had put it into my head that I need a super fast unicycle. I want something that can keep up to those people who ride bikes. I’m tired of having to ask them to slow down because I can’t keep up, but I’m not willing to switch over to the other team, if you know what I mean.
I don’t like the idea of Cokers because the huge wheel limits some of the take-it-with-you-everywhere-a-bility that I’ve come to love in my unicycles.
So, I’ve got a proposal for a wicked sick geared mini-giraffe.
Think of it:
-a 24x3 slick cruiser bike tire for pavement pwnage
-geared up about 1:2 (or 2:1, whichever one makes the wheel a 48" equivalent)
The idea would be to have the pedals just above the wheel, to keep the size down. The only reason I’m thinking giraffe is because these unicycles with geared hubs are not that cheap. I think I could do a mini-giraffe for cheaper that would give me the same kind of speed.
Does this make any sense?
I’ve attached a quick little Paint diagram.
(I believe this kind of thing has been done before, but I haven’t seen too many of them… That’s why I’m asking for feedback.)
Skippii made a really awesome one that I rode maybe 10 miles or so. He definately made a thread about it. I’d search it for you, but I want to go unicycling.
you would want twice as many teeth on the top sprocket than the bottom.
i have a design in my head for making a geared uni with chains and everything, but it sits at the same hight as a normal on, ill try to do a diagram of it one of these days
It isn’t much more compact than a Coker when you are extending the crankset over the wheel. In fact, I think it will take up even more space than a Coker if you are trying to transport it. The alternative is to have the cranks just slightly above the axle (like Pete Perons Purple Phaze)
Also less stable as your centre of gravity is higher, and hence slower than a internally hub geared unicycle. You can gear it up as high as you like, but the higher the gear, the more unstable it will be. I don’t think you’d go as fast as on a standard direct drive Coker simply because you wouldn’t have the confidence to, no matter how high you gear it up.
Also drivetrain issues- if the chain slips it can result in a nasty UPD. But same potential problem with any sort of geared hub. If you go for a geared system- make sure it is robust.
A 2:1 ratio on a 24" wheel will still leave you struggling to keep up with the bikes. On flat ground. Not to mention the mess to be cleaned up each time you UPD at high speed. Falling from a giraffe at 15+ mph is not pretty. Been there, on an almost-2:1 Schwinn Giraffe. Sure, you’re going real fast, but the smaller your wheel the less well it rolls over bumps. And being higher up, your angle of landing is just not good.
By the time you build a giraffe with gearing the way you want, you’ll find it’s about the same height, or more, than a Coker. It will still fit in a smaller space, but the Coker (or Schlumph) will have the advantage. Yours may be cheaper to make though, if you have a giraffe to start with.
I believe George Barnes (GB4 engineering) made one with a 26" wheel but the drive on each side was seperate so the axle didn’t need to be above the top of the wheel. This is much more complicated to do. there are videos on here somewhere of him going very fast down the side of a road, try searching for them and photos of how he did it.
EDIT: It might not have been him because I can’t find the video now, there was deffinitely someone who did it.
The videos suggest this is a very practical and cost effective beast. I wonder whether these were the first few rides on the thing? I note the cranks are just about as low down as feasible whilst still clearing the tyre. I think I want one.
