Newby question… Can you have a geared uni? EG a giraffe with two different
size sprockets or may be a derailer system though if you could change gear on
the move I don’t know or what about that ‘in the hub’ gearing system or does
that require the sprocket to free wheel?
This seams like a good option for using a uni as transport. I’d like to know the
pitfalss before I start to build one. Thanks in advance
RE: Gearing
>>Here’s something different: Has anyone tried using a large wheel,
and
>>gearing it down? Might be exactly the opposite thing one would want,
>>but I can think of two reasons: 1) Just to do it 2) Rides more like a
small
>>wheel (except turns), but gets over bumps easier.
I think Scott Cooper did this on his mountain Giraffe.Re: Gearing
bob <bob.cbx100@virgin.net> wrote in message
news:7h1net$k1p$2@nclient5-gui.server.virgin.net…
> Can you have a geared uni? EG a giraffe with two different size sprockets
or
> may be a derailer system though if you could change gear on the move I
don’t
> know or what about that ‘in the hub’ gearing system or does that require
the
> sprocket to free wheel?
There has certainly been at least one giraffe made with a 3 speed SA hub gear,
unfortunately I can’t remember who made it. The same guys, 2 brothers, later
made a 27" (IIRC) geared up to 42" equivalent. One of them then broke his arm
falling off because he couldn’t run fast enough to catch himself.
Both machines were present at the British Juggling Convention in 1995 and I
believe they were featured in “The Catch” at about the same time. I meant to
look it up last night, before posting, but forgot all about it. Maybe I’ll have
a look tonight, but I’ll probably forget again.
BTW, is that perchance Three Piece Bob, who was just setting off to drive down
through Africa last time I saw him?
–
Danny Colyer danny@mos.clara.net Who became used to playing unicycle hockey with
a team mate wearing a 3 piece suit.
Re: Gearing
bob <bob.cbx100@virgin.net> wrote in message
news:7h1net$k1p$2@nclient5-gui.server.virgin.net…
> Newby question… Can you have a geared uni? EG a giraffe with two different
> size sprockets
or
> may be a derailer system though if you could change gear on the move I
don’t
> know or what about that ‘in the hub’ gearing system or does that require
the
> sprocket to free wheel?
>
> This seams like a good option for using a uni as transport. I’d like to
know
> the pitfalss before I start to build one. Thanks in advance
>
>Bob,
Can you have a geared uni? Great question! I hope to have a working model that
will be suitable for long distance touring, sometime in the next year.
Unicyclists depend on direct drive unless coasting for short periods. The same
tension needs to be maintained forward and backward on the cranks for us to
balance. Typical bicycle derailers rely on a free wheel to move between gears.
Though it may be possible to use sprokets changing gears would only work if you
could stop momentarily and then move the chain from one chain ring to another.
But that brings in the question of a tensioning system, like the elbow shaped
thing on the back of your 10 speed. To my knowledge, internal geared hubs only
work in one direction. I have heared of people expirementing with this. I’m also
interested in hearing more. I think the down side would be the limited gear
ratio. So now-a -days I dream of a unicycle with a continous variable speed
gearing system. Possibilities I believe exist with either variable speed pulleys
or cone shaped pulleys, both using belts instead of chains. So I hope to appeal
to anyone out there like Bob that may have any ideas on this. I hope to create a
unicycle using all the best ideas and engineering and ride it across the U.S.
Farther and faster this time!
Tyler Bechtel
RE: Gearing
> >>Here’s something different: Has anyone tried using
> a large wheel, and
> >>gearing it down? Might be exactly the opposite
There was a guy (sorry, forget his name) at NUC last summer who had built a big
wheel for his son. This was a very large wheel (between 45" and 50" or so), and
the boy was not nearly tall enough to reach pedals on the axle, so he built
chains and a drive system with a crank on each side. It was geared down to make
it easy to pedal, but was not easy to ride. Sem Abrahams rode it in the NUC
parade, and said it rode very oddly because we big wheel riders are used to
expecting a certain amount of wheel motion when we turn the cranks. This wheel
only goes a very short distance, but still has the mass and inertia of a big
wheel so it felt very sluggish when I rode it.
Unfortunately the builder wasn’t quite finished developing his wheel. He told us
it wasn’t very strong yet and sure enough, when another rider was being helped
onto it, with his weight all on one pedal, it went the way of the taco. I hope
he can bring it to WA this summer!
Stay on top, John Foss, the Uni-Cyclone
Re: Gearing
I <danny@mos.clara.net> wrote in message news:MSCM100111A37@moscomputers.com…
> There has certainly been at least one giraffe made with a 3 speed SA
hub…
blah blah blah
> believe they were featured in “The Catch” at about the same time. I meant
I finally tracked down the piece in the June '95 issue of ‘The Catch’, scanned
it in and tried to mail it to Bob. Unfortunately it bounced.
I’m sure Stuart Ashman (the editor of the now defunct British juggling magazine)
wouldn’t mind me sending the 1,898KB GIF to anyone who’s interested (please post
privately, not to the group), but I must request that it not be republished or
put on the web without specific permission from Stuart.
–
Danny Colyer danny@mos.clara.net
RE: Gearing
Hey folks, who saw Tyler last night on Record Breakers? We saw it last night on
The Learning Channel. Tyler rode across the country last summer, to raise money
for Shriners children’s hospitals. He rode a 28", and what looked like a very
heavy big wheel (from Boneshaker?).
Tyler is a unicycling hero, and my hat’s off to him!
Also on the show we saw a glimpse of Ashrita Furman setting a backwards
unicycling record. He’s the guy who also holds records for underwater
pogo-sticking, somersaulting the furthest, one-footed jump roping, and other
records that just needed to be set. I got to watch him a few years ago doing a
record attempt at pogo stick juggling.
More unicycles on TV!
> > Can you have a geared uni? EG a giraffe with two
> different size sprockets
A simple form of this was used by Walter Nilsson when he rode across the United
States in 1933 for a Ripley’s Believe It or Not prize (a little more greedy than
Tyler but hey, it was the depression). He had two different sized sprockets on
his giraffe wheel, one on each side (most of his ride was done on an eight
footer). So depending on the terrain, he could take off the wheel and turn it
around. Not exactly on-the-fly shifting, but on a ride that long, the stops are
probably a welcome break!
> I think the down side would be the limited gear ratio. So now-a -days I dream
> of a unicycle with a continuos variable speed gearing system. Possibilities I
> believe exist with either variable speed pulleys or cone shaped pulleys, both
> using belts instead of chains. So I hope to appeal to anyone out there like
> Bob that may have any ideas on this. I hope to create a unicycle using all
> the best ideas and engineering and ride it across the U.S. Farther and faster
> this time!
>
> Tyler Bechtel
Something to consider when gearing up a unicycle is ridability. As the gear
ratio gets higher, the unicycle gets harder to ride and control. I’ve ridden
many different geared-up unicycles over the years (but not shiftable), and here
are some results:
My earliest experiences were back in 1980 when I wanted to get some speed out of
my Schwinn Giraffe (I actually wanted a big wheel, but chainwheels and chain
links were a lot cheaper). I tried a 32 tooth gear on top (28 on the bottom),
which made it ride like a 24". Very nice, and still very rideable. But not very
fast. So I worked my way up to 48 teeth on top, bringing it close to a 2:1
ratio. This was much faster, but very unstable and difficult to ride. Also very
hard to freemount! I rode it in a parade once (once!), but the slow pace of the
other riders was very hard to maintain safely.
On that unicycle I once did a 4 minute mile. The problem though, falling off at
that speed can be very nasty. You’re only going 15 miles per hour, but you’re
hitting the ground at an angle that you can’t run out of.
At UNICON XIII I rode Michael Kirsch’s 3:1 geared racing giraffe. It was a
beautiful machine, with the pedal axle just above the wheel, and a handlebar
system built onto the front of the seat with a cycle computer in it. But that
thing was so hard to ride, it took me several tries to get it going, and then I
had a very tough time just making one lap of the school parking lot. Michael
seemed happy with it though.
In 1982 Tom Miller built a geared-up standard unicycle. He constructed a special
hub with an inner axle that turned with the pedals, connected by chain to a
second “axle” just above the 20" wheel, connected by a second chain (on the
other side) to the outer axle that turned the wheel. The gearing was supposed to
make it ride about like one of his 40" big wheels. Unfortunately, it didn’t roll
over bumps like a big wheel, the small 20" wheel getting caught on lots of
things. Also it was very sluggish, and again had a big learning curve before it
could be ridden comfortably and safely.
To sum up, gearing up a unicycle will always make it harder to ride. With this
fact in mind, it would be a good idea to test your intended gear ratios before
building a complex gearing system. In other words, build up a giraffe and try
out different numbers of teeth on the sprockets before building a complex
mechanism that’s not useful to ride. I also recommend using the largest wheel
size you feel comfortable with. A larger wheel will roll over bumps better, plus
it will have more rotational inertia which will make it ride smoother.
Now build away, everyone, and don’t forget to send in pictures of your projects,
and stories to go with them!
Re: Gearing
John Foss <jfoss@unicycling.com> wrote:
> Also on the show we saw a glimpse of Ashrita Furman setting a backwards
> unicycling record. He’s the guy who also holds records for underwater
> pogo-sticking, somersaulting the furthest, one-footed jump roping, and other
> records that just needed to be set. I got to watch him a few years ago doing a
> record attempt at pogo stick juggling.
What’s the backwards unicycling record? I heard something like 56 miles, is
that right?
[…]
> To sum up, gearing up a unicycle will always make it harder to ride. With this
> fact in mind, it would be a good idea to test your intended gear ratios before
> building a complex gearing system. In other words, build up a giraffe and try
> out different numbers of teeth on the sprockets before building a complex
> mechanism that’s not useful to ride. I also recommend using the largest wheel
> size you feel comfortable with. A larger wheel will roll over bumps better,
> plus it will have more rotational inertia which will make it ride smoother.
Here’s something different: Has anyone tried using a large wheel, and gearing it
down? Might be exactly the opposite thing one would want, but I can think of
two reasons: 1) Just to do it 2) Rides more like a small wheel (except turns),
but gets over bumps easier.
— Marc (hertlein@umich.edu)
RE: Gearing
> What’s the backwards unicycling record? I heard something like 56 miles, is
> that right?
I don’t know off hand. A few years ago when Peter Rosendahl held most of the uni
records, he had a backwards record of over 40 miles, in a certain amount of time
to prove he was going at good speed. To find out the current record, go to your
nearest book store and check out the Guinness Book of Records. Let us know what
you find. Are you in a country where that record isn’t listed? What records are
listed in your country’s book.
I’m pretty sure the USA version lists 100 meters, 100 miles, tallest, smallest,
maybe biggest wheel, the Japanese kid riding across the country, maybe Land’s
End to John O Groats, and I guess backwards. What else?
Guinness is of course in the business of selling books, not listing every record
we can think of. They add and remove records from the book at random, so we can
only hope to keep them interested with cool unicycling feats.
Stay on top, John Foss, the Uni-Cyclone
Re: Gearing
I have been practicing steep uphill and downhill backwards riding. Maybe its a
good time to get a helmet
-Chris The uni-psycho
> What’s the backwards unicycling record? I heard something like 56 miles, is
> that right?
Re: Gearing
Has anyone tried powered unicycling? I am specifically thinking of servo
control or power assisted pedalling, similar in concept to servo power assisted
car steering.
Stu Swift.
Ps. This could be achieved using a measurement of applied torque through the
pedals driving a motor pressed against the tyre.
If anyone wishes to try this I can help with the theory.
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you don’t.
Re: Gearing
There’s a hilarious Road Runner cartoon where the coyote has a unicycle powered
by 4 rockets that spin the wheel. This is the opposite of a servo system!
Seriously, I can’t imagine any reason to power the unicycle with other than
legs/gravity, but it would be interesting to see.
—Nathan
<stuart@camcontrol.co.uk> wrote in message news:7j5q5v$dhr$1@nnrp1.deja.com…
>
>
> Has anyone tried powered unicycling? I am specifically thinking of servo
> control or power assisted pedalling, similar in concept to servo power
> assisted car steering.
>
> Stu Swift.
>
> Ps. This could be achieved using a measurement of applied torque through the
> pedals driving a motor pressed against the tyre.
> Pps. If anyone wishes to try this I can help with the theory.
Re: Gearing
Well, it could be useful for steep slopes, or large wheels. A variation without
a direct pedal to wheel connection could have virtual gearing, where the
electronics sets the number of wheel revolutions per pedal revolution.
Stu Swift
In article <7j9hhj$lhi$1@owl.slip.net>, “Nathan Hoover”
<nathan@paper2net.com> wrote:
> There’s a hilarious Road Runner cartoon where the coyote has a unicycle
> powered by 4 rockets that spin the wheel. This is the opposite of a
> servo system!
>
> Seriously, I can’t imagine any reason to power the unicycle with other than
> legs/gravity, but it would be interesting to see.
>
> —Nathan
>
> <stuart@camcontrol.co.uk> wrote in message news:7j5q5v$dhr$1@nnrp1.deja.com…
> >
> >
> > Has anyone tried powered unicycling? I am specifically thinking of servo
> > control or power assisted pedalling, similar in concept to servo power
> > assisted car steering.
> >
> > Stu Swift.
> >
> > Ps. This could be achieved using a measurement of applied torque through
> > the pedals driving a motor pressed against the tyre.
> > Pps. If anyone wishes to try this I can help with the theory.
>
>
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you don’t.