Re: Uni5 and wind

General
1

klaasbil_remove_the_spamkiller_@xs4all.nl writes:
>The big wheel has more surface to catch side wind; moreover, on
>average that surface is farther away from the twisting axis, which
>increases the momentum. Assuming that the wheel rolls forward at
>appreciable speed, the friction of the tyre that resists twisting will
>not be very large (it would be significant if the rider did a
>standstill).
>
>Does anyone of the test riders of uni.5 so far have comparative
>observations to make on this point?
Having ridden nearly 60 often-windy miles on uni.5, I can say that as far
as wind goes, I am still not quite sure how uni.5 compares with a Coker.
This is in part because the crank sizes are different and there is a
quality to the uni.5 not found in Cokers which may cause it to ride slower
anyway (due, I believe, to the ‘slop’ or wobble felt when you pedal).

I can say that in stiff wind, neither unicycle is especially fun to ride.
But I think the uni.5 handles slower speeds better, so it probably handles
wind better for this reason alone.

David
Co-founder, Unatics of NY
1st Sunday / 3rd Saturday
@ Central Park Bandshell
1:30 start time after 11/1/01

2

RE: Uni5 and wind

> >The big wheel has more surface to catch side wind; moreover, on
> >average that surface is farther away from the twisting axis, which
> >increases the momentum.

That’s the idea I was looking for. Inertia! The “ride quality” difference
between uni.5 and a Coker is inertia. The Coker, with a wheel that’s not
only bigger but heavier, has all this rotating mass far away from the axle,
which makes it ride smoother than a smaller wheel geared up to the same
speed.

Increasing the gear ratio will make this difference more prominent. That’s
why I think the uni.5 is a very useful compromise between speed and
rideability. I think it will be primo on a 700C road wheel. A 2:1 ratio, as
someone was suggesting, will make for harder work and less stability.

> This is in part because the crank sizes are different and there is a
> quality to the uni.5 not found in Cokers which may cause it
> to ride slower
> anyway (due, I believe, to the ‘slop’ or wobble felt when you pedal).

The “play” (slop) is only a very minor factor. If you introduced the same
play on a Coker, you would still find it a more stable ride. Years ago I
learned to ignore it on my 6 footer (until I got the thing spot welded).

But that’s the point. If you choose the bigger wheel for the nicer ride, you
have to live with the extra weight and the space it takes up. Now you have
more choices on how to go fast.

> I can say that in stiff wind, neither unicycle is especially
> fun to ride. But I think the uni.5 handles slower speeds better,
> so it probably handles wind better for this reason alone.

I didn’t ride uni.5 in much wind, but I’ve ridden enough unicycles to know
that uni.5 should be far less affected by wind than a Coker. It’s a matter
of surface area. In addition, with the Coker’s wheel being spread out
farther from the axle, it’s easier for the wind to push it around and aim
you off course.

I think I already wrote about a time when Ken Fuchs and I were riding big
wheels across a huge parking lot (Jones Beach) with a stiff crosswind that
literally forced us to “tack” like sailboats to make it across the parking
lot and end up where we wanted to be.

Stay on top,
John Foss, the Uni-Cyclone
jfoss@unicycling.com

“Vehicularly-Injured Sperm-Count seat: better known by it’s abbreviated
name, Viscount.” David Stone, on saddle preference