RE: Big Wheel Unicycle Questions
David Maxfield wrote:
>Tom Miller (Unicycle Factory) seems to be the most experienced big wheel
>builder in the US. He welds bicycle rims together. How well
does >this work?
It works very well. I’ve had three different ones, which were all made from old
Schwinn S-7 tubular rims. That means it’s a double walled steel rim which is
heavy, but very durable. Those rims are no longer made, so he has to use lighter
stuff these days.
PLEASE NOTE! In all the recent discussion about big wheels, I don’t think anyone
has mentioned the inherent weakness of large wheels. Even if made of the best
components, a large wheel is going to be more fragile than a small one made with
the same parts. Even with it’s double wall steel rim, my 45" wheel should not be
ridden off curbs, because it could cause flat spots in the rim. A big wheel will
always be “weaker” than a small one.
This means the wheel needs to be treated with respect, and not necessarily used
for rope jumping or hardcore MUni riding. But you can still put lots of miles on
it. My old 45" rode the New York City 5 Boro Bike Tour many times. That’s 36
miles on bumpy, potholed roads with a little brick pavement thrown in. After 12
years of ownership, I had a new wheel made for it, that’s normal wear & tear.
>Rideable Bicycle Replicas uses 60 spokes. Is this overkill? On the whole their
>unicycle looks more like a museum piece than a useable unicycle.
This wheel is supposed to look like an antique, and it looks cool. They don’t
really make unicycles, but will customize their normal bike design into one.
Number of spokes is probably less of a factor than rim strength, axle width and
quality of wheelbuilding.
>Coker Tires will use 36 spokes on theirs. At least one rider at Monrovia felt
>that their wheel seemed fragile. Could someone build a strong wheel that used
>their tire and tube?
The wheel could be built stronger, but I think that wheel will hold up fine if
not abused. You can probably even ride it off curbs, because the air tire will
absorb the shock where the hard wheelchair rubber of my wheel won’t. But the
main area of weakness is lateral. Try not to subject the wheel to unnecessary
side forces like putting weight on the wheel while it’s tilted over to the side.
>Tire: Most use wheelchair rubber. How well does this last? How does it affect
>the rideability/comfort?
Wheelchair rubber is nice because you can ride through a field of broken glass
where ordinary tires fear to “tread”. The rubber lasts a long time (unless you
spin too much) and can sometimes be flipped over and used inside-out when it
wears down. It will never have a blowout. But sometimes you have to worry about
separation, where the two ends of the rubber come apart and create a gap in
your tire.
Rideability is fine, though on a smooth floor there’s hardly any traction.
Comfort is proportional to the riding surface. Brick pavement will test your
tolerance.
>Size of wheel: Wheels range from 36" and up. What is an “optimal” size for a
>big wheel to be useable–not just a novelty?
Any big wheel is a novelty. The question is what do you want to use it for? Old
fashioned bikes had wheels up to 60", depending on the height of the rider. You
should be able to comfortably mount and ride, and your wheel should be able to
fit into wherever you need it to fit, storage-wise. These are probably the most
important considerations. A 40" wheel will fit inside a Volkswagen Bug, but a
45" will not (see http://www.calweb.com/~unifoss/garage/bigwheel.htm).
Crank arm length is another important factor. Most people use cranks that are
too short (in my opinion) for safe, comfortable riding. My 45" has 6.5" cranks,
which I consider to be perfect for that wheel and my leg length. The common 5.5"
cranks on a 40" Unicycle Factory big wheel are too short for me and don’t
provide enough leverage for uphill, quick stops, or even riding into a headwind.
I’ve ridden various sized wheels up to 63.5". The largest ones would only be
good for show, in fact the largest one was at the time the largest one ever
made. But at my height of 6 feet and good riding ability, I’d feel comfortable
cruising around on Ken Fuchs’ 56" wheel, if the cranks were a little longer…
John Foss