RE: revs per minute
> Anyway, we were talking about knees. He said it’s good to do
> 85 revolutions a minute while on that thing with the
> superfluous wheel. Does that sound right?
For a bike, yes. Though different actual numbers work for different people,
85 is somewhere in the middle of the various ranges I’ve heard.
The difference is, on a bike you have a choice. You select a gear to put
your pedaling speed into the optimum range for best power output. On the
less-complicated unicycle, cadence = speed. You want to go faster, you pedal
faster. So the concept of optimum cadence doesn’t apply.
If you’re looking for a good aerobic workout and aren’t worried about speed,
the value of 85 probably still isn’t true. This number is based on crank
arms that are a lot longer than the average street unicycle, and is also
based on a higher level of resistance in the pedals (from higher speed and
greater wind resistance). So for the equivalent aerobic workout, you’d
probably want to pedal faster.
If you are after exercise, you might as well pedal at the highest speed you
feel comfortable with. You can do intervals, where you alternate a
comfortable pace with the fastest pace you can maintain. Doing this sort of
thing will pay off at the convention, when you go up against the
mostly-untrained fellow racers in your age group.
Many people find, when they try to pedal faster than their “normal” speed,
that they start to oscillate or bounce up and down on the seat. This means
your body isn’t properly compensating for the rotating mass of your legs.
I’m going through this problem currently, as I’m riding a MUni with 170mm
cranks instead of my usual 150. If we were cars, we would attach little
weights to our legs to even out the bounce and “balance our wheels.”
Instead, we just keep practicing, until our bodies learn how to absorb this
oscillation and we adapt to the new pedaling speed. In other words, it may
take some effort, but you should be able to learn to pedal smoothly at any
rpm. Though shorter crank arms make this easier than longer ones.
> I tried it and was surprised to find that I ride at almost
> exactly 85 revolutions per minute.
That’s probably a common speed for a unicycle. “Fast” riders are always
somewhere north of 100rpm. When we race on 24" wheels, most of the shorter
events are well over 200.
> Is this supposed to have some impact on the knees – good or bad?
Since a unicycle puts relatively little strain on the knees compared to a
bike, I don’t know if speed is the main factor. On a bike, it has to do with
lots of quick “pushes” rather than a smaller number of longer, harder ones.
Most average people on bikes tend to pedal much slower than is efficient,
which puts a strain on knees. I am not an expert in this area; that’s just
what I have come to believe based on reading Bicycling Magazine for 15
Stay on top,
John Foss, the Uni-Cyclone
“If people want to truly understand mountain biking, they have to do two
other things: ride a unicycle, and master the trampoline.” – Joe Breeze,
one of the originators of mountain biking, in a conversation with Tim Bustos