My idea for building a $200 geared uni.

Well, here’s the plan so far, after examining how my 6-foot savage works:

Buy a new giraffe. $130 after shipping
Buy a smaller cog: $30, hopefully less

Put a new wheel on it:
I have a spare 26" rim/tire/tube. $40 to have it installed on the giraffe’s hub. I doubt I’d save much by buying the spokes and doing it myself–at least, the peace of mind I’d have knowing that it was done right would be worth it to me.
Put my fusion saddle/pedals on it from my 28".

Cut the giraffe down to a 2-footer, so the pedals are just above the top of the tire. I have a friend who welds and owes me a small favour.
Then, just shorten the chain.

That’s $200 even, and a vitual 33" wheel with a 22-tooth cog, 42" wheel with a 17-tooth.

Only problem I see right now is that UDC has no more $99 6-footers, and the 5-footer looks like it has the support bracer on the frame a lot lower, and might not handle 26" wheel. (The 6-footer has it 16 inches above the axle, so that would be easy…but it looks to be only about 12 or so over the axle on th 5-footer.) If it’s too low, I’ll probably be able to just cut it off…I won’t really need it on a 2 footer.

So, before I buy anything, what do you all think? Good idea? Bad idea? Will I be able to do a 150-mile ride like this?

So your idea is a low-rise giraffe, geared up, but not with changeable gears?

It works. Years ago, I had two. Neither was very satisfactory because they were cobbled together from bits, and I couldn’t get decent unicycle seats.

It works, in the sense of producing an effective wheel size of whatever size you choose, but at the expense of the intuitive control that you have on a conventional unicycle where the drive is driect into the hub. Also, chain lash is a bit of a problem, so you can get a jerky ride.

Also, you’re a bit higher up than you would normally be, and the wheel lacks the “rollover factor” and momentum of a genuine large wheel. That’s one reason why Alex Moulton’s wonderful creations are so seldom seen on mountain bike trails.

On a flat surface, with nerve and practice, you could achieve much on one of these. We’ll have a whip round and send you flowers and grapes.

Excellent. That makes me happy.

Yeah, I don’t have much interest in changing gears on the fly.
Being able to swap out cogs makes it more valuable to me than a coker, though. I live in a very hilly area, and my normal moring ride includes lots of climbs.
But, for the occasional time I need to go a hundred miles a day or so, having a virtual 42" wheel would be excellent.

Having gone a few miles at a time on my 20" 6-foot giraffe, I don’t think the height will be a big problem, and I’m getting used to the chain-drive. If it were not for the Savage Saddle, I’m sure I could have gone further.

Some people call those penguin giraffes. Here’s a thread about a geared up penguin here in Seattle: Abram Clark’s geared giraffe
There is a link to pictures and comments by Abram about building the penguin giraffe down in the thread.

Abram decided to use a lightweight and skinny tire. That makes the unicycle more twitchy.

I don’t know if would be more efficient riding wise than a traditional Coker. You may end up expending more energy and concentration riding it than you would a Coker. Climbing and rough pavement are going to be more of a problem than on a traditional uni like the Coker.

Using a 26" wheel would put you higher up. Would make mounting more difficult. A smaller wheel would make mounting more practical. Compensate for the smaller wheel by gearing it more. Abram was able to mount his by standing on the ground and jumping right up to the pedals. As the wheel gets bigger that type of mount would get progressively harder to do.

Thanks for the links…
very interesting.
I remember someone posted a thread and vid of them with penguin they’d made where the pedals were not connected–they were just a bit above the axle, so they each had a chain to the axle (otherwise they’d go through the spokes). That just seemed a bit too weak for me, but that’s what gave me the idea.
Didn’t know they were called penguins.
I wanted a larger wheel because I’m used to riding a 28 as my normal uni, and I thought the extra momentum of a 26 would be better for distance riding than a small wheel.
(Plus, having an extra 26 rim/tire is always nice.)

200 bucks is a lot

Penguin used to be a brand of unicycle, including a 4’ giraffe. Tom Miller made low giraffes with gearing and called them Travelers. That might be a good name for such a thing.

I’d stick with a larger wheel, for rolling over bumps and a little more momentum. Then again, I’d recommend you simply get a Coker rather than try to build something from near-scratch, unless that’s the approach you want to take. In the long run, you can switch cranks on the Coker and have a really nice ride.

I used to ride my Schwinn giraffe with something like a 1.8:1 ratio. It works, but handling is iffy and falling at high speed is bad!

But I wanna be DIFFERENT!
Ya know…beside already being on a uni!
:smiley:

Seriously, I do see your point, but really, I think it would be a lot of fun to see if I can build it, and that’s the main reason. Yes, perhaps the Coker would be more practical…but if I do the whole thing on a uni I build myself, I’ll be extra happy and proud of myself.

Thanks for the advice.
UDC was supposed to call me today, but they didn’t. I’ll call them on monday and order a new giraffe to hack apart and get this project started.

And how else does this technology progress unless someone experiments with it? Go for it, skippi.

With the harper hub and the schlumpf geared hub one of the biggest fears is going faster than you can run out in the case of a UPD. If I was geared up to a virtual 42" wheel AND I was an extra foot or two up in the air, I would never be comfortable with my ability to land and run out. Your machine sounds scary to me…

And that is my biggest hesitation right now!
Helmet, elbow pads, and ankle guards for this ride for sure…
I’m in a hurry to get it built so I have at least a month to train up my confidence!

cool

Okay, I’ve now talked to three local bike shops.
Looks like the plan, while still not figured out, is a go.

I need to figure out if it would be faster to have a wheel with a cog on each side, one 14T and one 17T, and swap the wheel around for hills/flats, or just go with 14T (or smaller) and swap cranks between 125s and 165s.
One guy says he thinks I could turn the wheel around and change chains in less than a minute for going up hills.

One problem with 29er’s and smaller wheels is that you’re not up as high as a Coker so you don’t have as much time to get your feet under you in the event of a high speed UPD. With a Coker you have just enough time between the time that your brain senses the “Oh oh, about to UPD” and the time your feet hit the ground to have a chance of landing on your feet and attempt to run it out. On a 29er and smaller wheel that window of opportunity gets smaller.

There is obviously an ideal height and a height that gets to be too high. That idea height is probably something slightly higher than the pedal height for the Coker. A 5’ or 6’ giraffe is in the too high category.

Oh, and check out this thread for George Barnes’ version of a geared up uni: Another geared unicycle…

That’s that one I meant. Thanks. :slight_smile:

That’s the one that I want.
Last I heard, I couldn’t “get one.” :frowning:

Batman

I agree – except for one possibility. No one has yet considered a link between this setup AND Batman. Now, if Skippii just got a good set of mylar wings, he wouldn’t have to run <scoff scoff> out a UPD – he could glide out a UPD. With the height he’d have from a 6’ giraffe, he could prolly achieve some good airtime, too!

David

Re: Batman

Just an update:
I ordered a new 5" giraffe to hack apart. So I’m over $100 into it now, so I might actually have some motivation to finish it.

Well, UDC got my address wrong.
So, still no unicycle–it was delivered to the wrong address. Luckily, they got it back, and I should have it tomorrow.
From now on, I think after I call them and talk to them and decide what I want, I’ll just ask them not to send it and order it online.