Newcommer. Questions on fast unicycles

Cool drawing.

1. would it be ridable?
Yes, nearly anything's ridable.

2. are there hubs with integrated planetary gear for unicycles?
Yes, but might not work with a chain drive.

3. would it be possible to turn?
I assume you mean steer, yes also.

3 1/2. Do good aerodynamics make a fast unicycle?
No. They (generally) don't go fast enough for distorting your body
position to be better than an ergo position that lets you balance,
breathe and pedal faster.

You don't want to pedal with hands and feet at the same time. When
pedaling with fee, we use one hand to stay steady on the cycle, and the
other to help in balancing. You can get by with no balancing hands,
which we generally do in road racing, but on the track things happen
fast, and a free hand can be very useful.

The fastest unicycles currently are 36" wheels, and geared-up 29"
wheels. Someday maybe geared-up 36" wheels. Read up on those to learn
more about what a fast unicycle currently is, then work from there.


--
johnfoss

John Foss
"jfoss" at "unicycling.com" -- www.unicycling.com
-----------------------------------------------

"The worst thing you can do on a unicycle when you land is stop dead."
-- Kris Holm, world's expert on high-consequence unicycling
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johnfoss wrote:

3 1/2. Do good aerodynamics make a fast unicycle?
No. They (generally) don't go fast enough for distorting your body
position to be better than an ergo position that lets you balance,
breathe and pedal faster.




For existing unicycles, this is certainly the case, but if we really
start to push the limits of technology, it may not be the case forever.
If someone wanted to start doing Bonneville Salt Flats-style speed
records on a unicycle, he could develop something like this with a gear
of something like 80 or 90 gear-inches, which would go fast enough to
get benefit from an aerodynamic position. Once you get above 20 mph,
aero drag starts to take over as your major limiting speed factor.

A challenge would be that you'd have to find someone who was not only a
strong rider, but also willing to pilot an unstable one-wheeled
contraption at speeds above 20 mph. Not to mention, an unstable
one-wheeled contraption with a row of sharp teeth aimed at your neck.

I wouldn't expect the hand-crank to be worth the extra complexity, but
you could construct something with a seat and bars which put you in a
more aerodynamic position than is normal on a unicycle.


--
tholub
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tholub wrote:

A challenge would be that you'd have to find someone who was not only a
strong rider, but also willing to pilot an unstable one-wheeled
contraption at speeds above 20 mph. Not to mention, an unstable
one-wheeled contraption with a row of sharp teeth aimed at your neck.




Not a challenge at all. just browse our galleries and take your pick of
the freestyle/street teenagers



I really hope you make this thing. . . I agree that a 1 to one ratio
would be pretty important for balance issues. would we be able to keep
that 1-1 while shifting?

I also think the best advice i can offer you is: go get a unicycle!!!
learn how to ride it (we'll all help as much as we can) and then uuse
what you learn to help you build this marvel!!! you can get a nice
starter unicycle (Torker LX) for under a hundred bucks.


--
Sgaterboy
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I think aerodynamics does start making a difference at something like
15mph or so. Given there are quite a few people who can hit 20mph
without problems, they'd probably get benefits from better
aerodynamics.

The position looks very cramped, maybe moving the handle higher would
be nicer. alternatively if you're bothering making a chain drive from
the handle to the wheels, why not have the pedals on a chain drive too,
that way you could lie the person right down, making for a very aero
position. It'd be jolly hard to ride an upside down recumbent unicycle
but I'd guess there are people who could. If you had guards so you
didn't hit your hands on crashing and kept the rider as low down as
possible it could be much more rideable, as you might be able to launch
from the lying down position.

Like Mike says, plantetary gears are a bit limited in how high they go,
although on the 36" wheel with the 1.55x gearing, it is equivalent to
quite a decent sized bike gearing.

Joe


--
joemarshall

my pics http://gallery.unicyclist.com/albuq44
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joemarshall wrote:

The position looks very cramped, maybe moving the handle higher would
be nicer. alternatively if you're bothering making a chain drive from
the handle to the wheels, why not have the pedals on a chain drive too,
that way you could lie the person right down, making for a very aero
position. It'd be jolly hard to ride an upside down recumbent unicycle
but I'd guess there are people who could. If you had guards so you
didn't hit your hands on crashing and kept the rider as low down as
possible it could be much more rideable, as you might be able to launch
from the lying down position.
Joe



I was looking at the riding position.. I think it might be harder to
shift your weight forward and backwards with your body so horizontal. I
agree that the rider would be better off sitting more vertical


--
Sgaterboy
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I we look at bicycles (and tricycles) where fore and aft stability is
not a significant issue:

The Tour de France involves high speed riding uphill and down hill for
long distances. If there were any advantage for hand/foot combined
power in this type of riding, someone somewhere would have made the
point, even if the rules had not allowed them to enter the race.

Ditto for track racing and time trials and so on.

Bicycles weren't always the shape we see and accept now. They have
evolved this way for a number of valid reasons.

The exception is straight line maximum speed, where HPV enthusiasts
often go for a recumbent position, with the rider bracing his back
against the back of the seat, and pushing extra hard against the pedals
and turning a very high gear.

I have ridden purely hand-cranked vehicles. It's hard work.

I doubt that in any but the most carefully selected circumstances, the
additional weight and complexity of the hands/feet drive and the
additional co-ordination problems that come with it, would be anything
but a disadvantage.

Add to that the further problem of balancing on one wheel...

This is no more than an interesting idea, which is right up there with
kangaroo unicycles, geared-up giraffes, and the like, as fun to try,
but inherently less effective and efficient than a conventional (or
geared) uni.


--
Mikefule

"We shall do best to think of life as a process of disillusionment."
Arthur Schopenhauer (whose daddy appears to have taken his T-bird away
rather early in his life.)
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probably, some gyrostabilizer could be used.

To create gear such schema could be used: chain goes flom legs drive to
hands drive and than from hands drive to wheel. Standart bicycle
components could be used.

I would say that hands drive can give some advantage if it is well dome
and you have enough muscules. I was riding centaur for half a year and
I can tell I like it. And I want to build something that uses my hands
power.


--
mozg
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Mikefule wrote:
I we look at bicycles (and tricycles) where fore and aft stability is
not a significant issue:

The Tour de France involves high speed riding uphill and down hill for
long distances. If there were any advantage for hand/foot combined
power in this type of riding, someone somewhere would have made the
point, even if the rules had not allowed them to enter the race.

Ditto for track racing and time trials and so on.

Bicycles weren't always the shape we see and accept now. They have
evolved this way for a number of valid reasons.

The exception is straight line maximum speed, where HPV enthusiasts
often go for a recumbent position, with the rider bracing his back
against the back of the seat, and pushing extra hard against the pedals
and turning a very high gear.

I have ridden purely hand-cranked vehicles. It's hard work.

I doubt that in any but the most carefully selected circumstances, the
additional weight and complexity of the hands/feet drive and the
additional co-ordination problems that come with it, would be anything
but a disadvantage.

Add to that the further problem of balancing on one wheel...

This is no more than an interesting idea, which is right up there with
kangaroo unicycles, geared-up giraffes, and the like, as fun to try,
but inherently less effective and efficient than a conventional (or
geared) uni.



and yet someone, somewhere, said "I got an idea!!! how about if we only
use ONE wheel!!!"


--
Sgaterboy
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I think it's a really neat idea, but like he said, it's preliminary.

I say build it, try and ride it, and when (if) that fails, find someone
else to ride it.

It may work real well, it may not, and it may just be another unique
(and sexy) unicycle design.


--
onelesscar

mmm...i love my qu-ax...and now my kh 20...
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Nice concept

My thoughts:
- The current limiting factor for unicycles going fast is how fast you
can pedal, not how much power you can exert. Even with 1:1.55
epicyclic gear (www.schlumpfdrive.com) available now, it's still a
relatively low gear. Hence having an extra power transmission via your
arms will not help increase speed until the gear ratio get much bigger.
Frantically working your arms on a unicycle only destabilises it and
slows you down.

- The low, stretched out position you have there is good for going
fast. When I'm riding fast (~30km/hr), my body position is really low
(in fact from photos I've seen I have my back at about 30 degrees to
the ground.) The reason is that this lowers your centre of gravity and
and makes you more stable.

- Aerodynamics certainly play a part once you go above 25km/hr, and
most good riders can ride above 30km/hr for short periods. I think the
fastest speed I've heard of was Christian Hoverath clocking 48km/hr
downhill on a 36" Coker.

I'd love to ride one though- it looks so cool

Ken


--
GizmoDuck

'SINZ Unitour 2007' (http://www.sinzuni.org)
'www.adventureunicyclist.com' (http://www.adventureunicyclist.com/)
'Laos Unicycle Tour 2006' (http://www.laosunitour.org)

The Monguni tour 2008....
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