Seated hand-driven unicycle...

I’ve had a bit of time to think about my invention before we start to build it. Given that I’m willing to put in hours of practice and so on (because like regular unicycling, it’ll be fun!) how ridable do you think this contraption will be?

Any suggestions on ways to learn to ride it and also on names for it?

Thanks,
Andrew

glynis

Seated hand-driven unicycle…

Andrew,

How about “The Crouching Giraffe”?

Do you really need that second tube running from the saddle to the chainring hub? Seems you could save yourself some weight by losing it. As far as riding it goes, that all depends… on your determination! I’d also suggest a full-face helmet or some kind of guard over the stern of the chain ring, or you’ll be re-naming it “The Queensland Chainring Massacre”. Keep us posted on your progress!

– Glutes

expanding on gluteous’ suggestion we might want to go as far as
‘crouching giraffe, hidden glockenspiel’?
(with apologies to klaas bill)

that chain guard is a REAL good idea

I just thought that the added strength from that second tube would be neccessary. Also, let’s keep in mind that I’ll be using the bottom bracket section of a bike frame so that tube would already be there.

That chainring guard does sound like a must!
Andrew

Seated hand-driven unicycle…

Hmmm, yes, Dave, well… I guess with all that forward-and-above-the-saddle weight (Gods! Hyphens are great things, aren’t they?), forward UPDs would be highly likely to occur, and with that “verticle top tube”, after one hard forward UPD, one’s glockenspiel would indeed be hidden, or at least wish it had been! Please don’t consider this a negative criticism of your invention, Andrew! Aside from the lewd imagery that Dave tricked me into mentioning, I think your contraption could work! “Crouching Giraffe” was not a sarcastic comment, but a reference to the mechanical similarity to a giraffe uni, but with the rider’s position obviously reversed. “Crouching Giraffe, Hidden Glockenspiel” does have a certain ring to it, but consider also “Crouching Giraffe, Hidden Agenda”, or “Crouching Giraffe, Hidden Digeridoo” (you could incorporate one into the frame… y’know, keep that up-and-down tube after all), or finally (maybe), “Crouching Giraffe, Hidden Other Wheel” for a built-in retort to those you-know-whos that feel compelled to let us know that they can count past zero.

– Glutes

Looks good! You may need to fiddle around with the size of your chain rings to find the right ratios. You may find that to move the wheel enough your arms are flying around quite fast. Mind you, if you make the upper ring much smaller you may find it too hard on your arms (unless you’ve got arms as strong as your legs). There’ll be a happy medium somewhere in there.

It reminds me of when I used to pedal my old tricycle using my hands - stomach on seat, feet on back axle, brain in neutral :roll_eyes: I used to steer using my feet as brakes on one side or the other, it didn’t work very well and made my mum furious as it knackered my shoes:(

Have fun!

Graeme

That’s very cool. Have there been other one wheeled handcycles produced? I would have appreciated being adept at a unihandcycle when a crunched ankle kept me off of my unicycle for nine months last year! I have a feeling a handcycle would be easier to learn than a regular unicycle, assuming that one has adequate arm strength to maintain control. I realize that this is beyond the scope of your current project (and completely beyond the scope of my limited mechanical prowess), but are gears more of a possiblity on a unihandcycle than a regular uni? Or is that just an assumption I have because it would look like you are doing a wheelie on a mountain bike?

Good work! I look forward to its production.

  • andrea

Looks interesting, although I have to say, it looks like you’d have to be in a really odd posture to ride the thing. If that’s a 24" wheel, then the position of the foot pegs means your legs will be nearly horizontal, and the hand cranks will be above your head…

I’d be inclined to raise the seat height and drop the foot pegs. Also, you should probably try to figure out where the cranks should be positioned to get optimal power (while at the same time, not killing your arms due to lack of blood flow).

-Jon

just as long as u don’t slip forward whilst ridin’.
great contraption, if it ever gets made, i’d love 2 see the video

It looks like the rider would be in a slightly recumbent position. Recumbent unicycles are notoriously difficult to ride. A more vertical rider position might make it easier to ride. But then again, on a bike doing a wheelie having the feet in front of the rider makes it easier.

Maybe having a rider position similar to someone on a bike doing a wheelie would be better? Maybe??

Picking a good rider position and rider posture is going to make a lot if difference in how hard the thing will be to ride. I wouldn’t be surprised if you end up needing to make two or three prototypes before you get a rider position that works.

I think John Foss has a picture of a recumbent unicycle on his web page <http://www.unicycling.com/> but his site is down at the moment so I can’t go look for it.

Re: Seated hand-driven unicycle…

A helmet will never hurt you, but more importantly, I think you will want to include protection of your chainring from the ground. This was a big problem with Eric Kolb’s recumbent:
http://www.unicycling.com/garage/recumben.htm

I’m surprised his held up for the entire UNICON with all the pounding that chain and ring must have taken, including when I tried it.

Before building anything, I highly recommend you put some axle pegs on a regular giraffe and learn to ride it. This will give you a much better understanding of where you’ll want your body mass to be in relation to the wheel and pedals.

I think you’ll want to finish up with a design that has your feet on the axle. You will probably learn to ride the thing standing up first, and gradually get to sit down as you get better at it. I imagine it will be a lot harder to steer when you’re sitting down.

Gear ratio should be in the neighborhood of 1:1. Believe me, it’s enough work that way, especially in the learning stages. You can raise the gearing as you get good at riding it. Compared to legs, arms are weak! Use standard block pedals, perhaps with some tape built up on them to smooth out the shape.

Randy Barnes of southern CA converted a Schwinn giraffe to one of these in the mid-80s or so. he cut off the seat tube, leaving about a 1’ section which he angled to the front to serve as a handle. Then he attached a seat to the back, but I think it was fairly high up. I think he had pegs on the axle for his feet, and a significant percentage of his weight was probably on them, but I don’t know because I never tried one.

I’m not real good at hand-cranking my giraffe, but I can now make figure 8’s (and spins) doing it. A lot of the steering comes from adjustments of my feet on the pegs, and is kind of like riding a B.C. wheel with a drive mechanism. Don’t underestimate the need for your feet to help control the thing.

Also, don’t let the pre-existing design of the bike you’re working from compromise the rideability of your hand-cranked giraffe. If you put the seat in a certain spot because it conforms better to the old frame, it means you’re not serious about making a design that’s easy to ride.

Based on the way most giraffes are built, strength should not be a major issue, except around the seat. Your weight will either be on the pegs or on the seat (or both), but there won’t be much force up around the pedals.

Good luck!

Andrea,

I don’t have a link to it, but there was a thread about geared giraffes that I started with the impression that it’d be quite easy to make one. If you find the thread you’ll see that it’s unfortunately not as easy as just adding a derailleur from a bike. It’d be alright if you didn’t plan on having any power when pedalling backwards.

Jon,

That was just a quick sketch and you’re right, it is a bit odly shaped. The actual thing will hopefully put the rider in a position with arms almost horizontal and legs either on pegs out in front but on an angle of about 45 degrees or on the axle.

James,

As I’m sure you can imagine, there’ll be many pictures and videos of this beast WHEN it gets made :).

Johns,

Thanks for the advice. Unfortunately I don’t have a giraffe to put pegs on but I’ll get one some day. There is (or was) a 6’ giraffe on sale here in Australia but I’ve just finished buying all of my custom muni (which I can’t pick up from the post office until tuesday!).

I will make sure I have the rider in the upright position. Maybe I could have some pegs on the axle like you suggested and then another set out in front to use when I’m more experienced. Then I can go from standing, to sitting with feet on the axle, to sitting with feet out in front.
Do you have any photos of Randy Barnes’ invention?

The only part of a bike frame that I plan to use is the two tubes connecting to where the bottom bracket is held. This seems to fit in nicely with the design to me.

Thanks, everyone for all your help,
Andrew

Couple of ideas:

  1. Go to a gym and try one of their cycling-with-the-arms machines. It should give you insight into arm placement relative to the body.

  2. Include adjustability back-and-forth of the seat and foot pegs. Kindof like an aluminum adjustable cane. This would help get the body position over the wheel correct for different riders and as prototype flexibility.

  1. We don’t have these at our local gym. Coyuld you please describe them for me?

  2. That does sounds like a great idea, but I’ve got to keep it pretty simple. I’m doing most of the designing and my friend (or boss) is going to build it for me. I’ll help with the building but I don’t have any metalwork experience and so on. He owns a bike shop and is always really busy so I don’t want to give him too much for him to do.

Thanks for the advice,
Andrew

The arm machine is a couple of cranks with, I think, variable resistance, that mimics the double-handed winches on sailboats. Just like bicycle cranks but with better hand grips.

See this link for an example: http://www.endorphin.net/en351b.htm

Also this one, which may look a little familiar! http://www.endorphin.net/en370.htm

The other day I was driving home and I saw someone on a wheel chair with hand cranks. From what I saw, he was going about as fast as the local bicyclist. I didn’t get a good look as it was across a bunch of lanes, but I could have sworn that the cranks were in kangaroo style. I would assume that this would give much greater power, much like rowing.

I’m not sure if this would be helpful with your design, but it’s something to think about.

Daniel

Thanks for the links.

Daniel,

I’ve also heard of people using the kangaroo-style setup for cranks but I think that since I’ll be pedalling both forwards and backwards it’ll be easier to use the normal setup. I’ve said it before and I’ll say it again…this’ll be like going to the gym but fun!

As for all you other Aussies out there who are going to UniNats, I’m very confident that I’ll have this made by the 4th of October (UniNats) easily. I’ll make sure I bring it along with me so you can have a ride of it.

Andrew