Brakes? How?

RE: Brakes? How?

> Yes, of course one would have to practice racing to have a reasonable
> chance of winning. I assume John is speaking from personal experience
> rather than objective physiological data. The muscle groups are being
> used faster and as a consequence more concentration and training is
> required to control them, but is the movement really different, other
> than being faster?

You seem to be missing my argument, every way I try to describe it. Yes, the
movement is different. Though your feet are still going in a circle of the
same size, the forces you need to apply, and the areas of the muscles you
need to use, ARE DIFFERENT. This is based on personal experience, and a
practical understanding of physics. Personal experience tells me where I get
sore if I ride fast, after a whole year or so of not riding fast I’ve done
this a lot. It’s immediately obvious to me where I have to work differently
to ride at racing speed as compared to MUni speed. The main areas are:

  1. Upper quads (lifting legs up)
  2. Hamstrings (pulling lower leg back)
  3. Side of lower leg (muscle that lifts front of foot)

None of those muscle areas are needed for slow riding. If you just push down
on the front pedal, everything else takes care of itself. This cannot and
does not work if you pedal at speeds around 200+ rpm. This is my last
attempt at explaining this phenomenon.

> Sorry, I wasn’t considering hills that are too steep to ride
> up or down,only those that would be challenging (not those
> that are nearly impossible) to ride up or down.

Challenging hills don’t necessarily push the limits of traction. But the
definition of challenging is a personal one, depending on experience and
skills. A more skilled rider can manage a greater degree of steepness than a
novice. One useful skill for hilly trails is the ability to keep the tire
sticking on those steep slopes.

> Control can be maintained with a sliding wheel. It is probably even
> easier than coasting. I’d say that anyone who can glide, can maintain
> control sliding the wheel over the riding surface. However, I’d not
> aware of any experts at this skill. Who has done this?

I think a lot of us have, depending on your definition. There is controlled
slide vs. uncontrolled slide. I guess the difference between these two is
whether or not you get some sort of results from moving the pedals.

Riding up a steep slope, most occurrences of loss of traction mean an
instant dismount. Your “balance envelope” (as George Peck calls it) is so
narrow you don’t have the leeway to correct for such sudden movements.

Riding down a steep slope gives you more chance to respond and hopefully
control your slide. Again if it’s at or near your personal steepness limit,
once the tire lets go you may be instantly pushed outside of your balance
envelope. But if you’re moving along and the unicycle is still under you,
you can try to pedal or brake to keep it where you want it. I’ve done this
on the giant sand dunes as seen in Things not to do
(http://www.unicycling.com/things/default.htm), and on leaf-covered slopes,
among other things. Here’s a picture of David Poznanter doing just that:
http://tinyurl.com/dh3

> I can understand that you do not think that a more rigorous
> understanding of physics can help you ride muni better, but
> it certainly can.

Of course it can. I don’t know that I implied otherwise. I just said I’ve
never taken a physics class in school. Being around unicyclists and circus
people for 20 years has taught me a lot. At least enough to see how “fake”
WWF wrestling is… :slight_smile: As well as enough to understand the forces that
keep a unicyclist up or bring him down.

> I don’t understand what is meant by “we can’t coast”, when a
> significant number of unicyclists can coast.

Okay. “Unicycles can’t coast.” The point being that it’s a fixed-gear
vehicle, and when riding on trails, coasting is not an option if you intend
to continue riding. We’re forced to deal with our pedals in whatever
position they are when we reach an obstacle. This can be pre-planned for
single obstacles, but when there are several in a row, we are limited by the
fact that the unicycle can’t coast. “We” can’t reliably coast over a bunch
of tree roots, for example, either.

Aside from the obvious balance thing, the big difficulty thing that
separates us from mountain bikers is our inability to coast over obstacles,
or to use the freewheel to reset our pedal orientation.

> Clearly not objective measurement.

That’s what is meant by “rough numbers.”

> The snake schnapps was also very high in alcohol content.
> I’d like to think that it was the alcohol content that
> had the most effect on me the following day.

I have had somebody Chinese explain to me the liqueur that’s used in those
concoctions and yes, it’s a very high alcohol content. But wouldn’t it be
cool to be able to say you were sick from the snake bile?

> Thank you John for a very interesting discussion.
> You don’t need to
> comment on this thread further on my account.

Oops. Okay, I’m done. On to the saga of 700C racing!

JF

Brakes??? How???

C’mon guys… Unicycling isn’t science…its common sense. You dont slow down by pedaling faster… you slow your pedaling to were its controlled, so you dont end up going too fast and going out of control. how? By using using your leg muscles to resist the pressure of the pedals coming up from the rotation… if you didn’t, then you would keep going faster and faster as the pedals rotated freely.

Jon~

Ummm…

All this Physics 101 stuff is cool, but… :o Zzzzzzz

What about the brake question? It’d be nice to get some more info on the mechanical aspects of attaching and using a brake to slow the uni.

fer example, what about that? You’re not using the brake to actually stop, right? So, are you going to get enough pressure on the mounting bolt to hurt it? … Anybody?

Are brazed-on posts necessary?

Rick

Re: Brakes? How?

“John Foss” <john_foss@asinet.com> wrote in message
news:mailman.1023985528.6779.rsu@unicycling.org
> Riding up a steep slope, most occurrences of loss of traction mean an
> instant dismount. Your “balance envelope” (as George Peck calls it) is so
> narrow you don’t have the leeway to correct for such sudden movements.

I’m trying to learn to hop out of this situation, hopping as soon as you
start falling. I can get the hop out of the fall about 50/50 but then I
haven’t got side hopping up the slope good enough to keep going.

Joe