Re: Uni on a tightrope
I did research and tried unicycling on a tight rope many years ago and
may have a few ideas to offer that may not have yet been suggested.
David <straitjacketcircus@'DELETETHIS’totalise.co.uk> wrote:
>Thanks for all the help offered 
It seems a very hard subject to learn
>about, I guess it is mostly going to be about learning by hard work along
>with trial and error.
>I am loath to use a balance pole as suggested a couple of times as my
>tightrope experience is all without balancing aids. I feel they detract from
>the performance unless being used for wire walking at a height, i.e. 20 - 30
>feet or more. And if you suddenly add things like balance poles to an act
>which otherwise didn’t have one, people tend to assume that you are have
>started cheating in some way. And in a sense they are correct! Also I have
>to work in restricted space a lot of the time, and a 14 ft pole just
>wouldn’t cut it.
People (professionals) have definitely done unicycling on a tight rope
without a balance pole. Also, you could use a shorter balance pole and
could compensate for the shorter length with more weight in the balance
pole, particularly more weight at the ends. The use of the balance pole
can be thought of as a stepping stone towards riding without one by
reducing the length and/or weight of the balance pole. Several balance
poles of varying length and weight may help attain the ultimate goal of
using no balance pole at all.
>Leo white said…
>
>^snip^
>Try it with your Monty Tyre at low pressure …
>^snip^
>
>I haven’t got a Monty tyre. I do have an Onza on my trials uni and I will
>give it a go on that. Sounds like fun, how did it turn out for you?
This is definitely the hardest way to do this (I’m not sure this
suggestion was even really serious).
>Gilby said…
>
>^snip^
>You want the wire tension to be as tight as possible.
>^snip^
True, but stay well below the tension rating of all components. I’d
recommend a tension of about 1/10 the rating of the weakest component.
A torque wench on the turnbuckle, adjusted (multiplied?) by the
effective lever of the turnbuckle would help measure the actual tension.
A physcist or mechanical engineer could explain this in more detail and
I’d welcome anyone with such skills to do so.
>I will bear that in mind, thanks for the advice.
Professional tight rope walkers and tight rope unicyclists use a minimum
of 5/8 inch thick tight wire with 3/4 inch or 7/8 inch more common just
for added grip between the foot or wheel. The added strength of such
wide wires is not really needed, but is still useful in case of major
defects in the wire. A greater number of smaller diameter strands will
be stronger and less prone to catastrophic failure!
Be careful about turnbuckle (wire tightener) strength as these are
usually rated at about 1/10 the strength of the same thickness of wire.
In fact, you can almost ignore the wire as the component that may fail.
Usually it is the cast steel components with 1/10 the strength or the
wire support structure that will fail. I recall that a U shaped support
structure of a professional’s portable tight wire buckled when it was
tightened after numerous prior shows; it was obviously far too weak to
support the wire (actual strength/failure strength ratio not large
enough) and the repeated stress (fractures) finally did it in!
The wheel should have a 1 3/4 inch or wider rim with a molded rubber
compound put in with about 1 inch wide track for the wire as I recall.
I never built such a wheel, but rather used a bare 3/4 inch rim instead
that didn’t work very well due to low friction between it and the wire.
Tom Miller probably has much greater experience in this area as well as
in all areas of tight wire walking and riding.
In designing a tight wire, remember to use components rated 10 times
greater than the needed strength. Be sure to identify and focus on the
weakest components. Almost more important, consider how the design
might fail and adjust it to reduce the possibility of injury or death
due to a component failing (such as a turnbuckle or chain link, etc.)
For example a loose saftey (backup) cable or chain could prevent a
broken turnbuckle from becoming a lethal projectile; obviously a safety
(backup) cable or chain must absorb the “failure energy” without itself
breaking.
Also consider safety of the rider when he falls. Obviously, a two foot
high wire will almost always be safer than a twenty foot high wire. A
saftey net should be safer than no saftey net. Soft grass should be
safer to land on than hard concrete. Even tar, especially in the
hottest days of summer, will be slightly softer than concrete. Finally,
don’t forget use full body armour or at least minimal protective gear.
Hope this post has been of some help and hasn’t repeated too much
information from prior posts.
Sincerely,
Ken Fuchs <kfuchs@winternet.com>