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!