Too much weight on my hands?

On Tue, 26 Jul 2005 11:14:54 -0700 "Tom Nakashima"
wrote:

The reason for keeping
the seat level, is that I can ride closer to the nose of the saddle or what
the old-timers called "riding on the rivet" on long straight-aways, when
riding at a fast pace.

I had never heard this expression before it was mentioned during OLN's
coverage of the TdF. In that comment they seemed to suggest that it
implied that the rider was tired. That doesn't make sense to me. If it
makes sense to you can you explain it to me?

Or did I catch the OLN comment wrong?

It seems to me that sliding forward on the saddle would be an easy way
of shifting your CM forward a bit, which would be useful, as you
imply, when riding hard.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

On Tue, 26 Jul 2005 13:26:44 -0600 wrote:

b) Pulling up on the backstroke actually applies almost no
force on the pedal at a normal cadence:

"One can see that for the strength functions used to create
the above plot, most of the force that turns the pedals
comes in the down stroke, very little in the up stroke."

http://www.analyticcycling.com/Pedal...edal_Page.html

"Under these conditions the foot is not used to produce an
upward force on the pedal. Only under slow rotation
conditions, such as during a hill climb, will the rider tend
to pull up on the pedal as well as push down during the
'power' part of the stroke."

http://www.princeton.edu/~humcomp/bi...t/histo_27.htm

Interesting stuff. Was this taken from real data on real riders?

I've always been annoyed by the fact that most of the time my rear
foot is just taking a "free lift" up the backside of the stroke. Since
the torque I get out of this will just be that due to the difference
between the forces on the 2 pedals, I've always felt that I wasn't
doing nearly as well as I should be able to. Still, it takes me a
concertad effort to just take all the weight off that foot, let alone
pull up, throughout a long haul.

How well do most of you out there do? Can you consistently keep all
weight off the upstroke foot?

I find climbing to be different. There I will consistently pull up on
the upstroke. How about you?

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

Jim Adney wrote:
On 26 Jul 2005 10:37:42 -0700 "41" wrote:

you seem to discount the fact that the saddle exists, and
that if tilted up it restrains or supports the rider in the forward
direction.

So restrained, the upper body then rotates around the
saddle, not the BB. I've said this many times and am yet to hear you
acknowledge this. Why?

There's not debate on the effec t of the saddle/seat angle. Everyone
here has agreed to that thruout.

Nice way to avoid the issue. You still won't admit that with nose up it
restrains the forward motion and makes your claims based on torque
about the BB incorrect, since you neglect this reaction force, and
require it to be taken up by the hands instead. You are right there is
no debate about this because you always avoid the issue.


The reaction torque from the torque exerted on the pedals will produce
a backwards force on the body regardless of the body position.

Do recall that the most effic ient pedalling includes an upstroke as
well as a downstroke.

I see that among all the other things you claim to master but really
don't understand, we can add torque. Both of the motions you refer to
produce torque in the same direction, and the reaction torque to each
is also in the same direction. The resultant effect of each is to push
the rider back onto the seat/saddle.

The tendency for that upstroke pedalling torque to rotate the person
about the BB is cancelled by reaction forces at the saddle, leaving the
pull exerted on the pelvis by the femur and the associated muscle. You
throw around claims of "fail to master" rather freely, indeed since
your first condescending reply to me in this thread. This betrays
insecurity on your own part.


I am at a loss to explain why King George thinks that moving the
saddle forward will reduce the weight on the hands.

I believe I explained many times and in detail how simply moving the
saddle back OR forward alone is not sufficient to solve the problem of
weight on the hands; other factors must be taken into account- tilt of
the saddle and size of the gut, to take only two examples. Also, I
believe you are conflating excess weight on the hands with excess
pressure on the hands. Weight is down only, pressure has also a
fore-aft or even up component.

Nice waffle. Your previous posts were all quite clear on your claim
that moving the seat forward would reduce the weight on the hands.

There's no waffle. If the saddle is tilted forward, it won't reduce it.
If the saddle is such as to restrain the forward motion, having the
nose up, it will. Likewise, moving the saddle back may reduce weight on
the hands if e.g. the gut is big enough to get compressed in the more
bent posture. I believe I listed several other such factors. Actually
reading what you are criticizing saves much bandwidth but I see that is
not your goal:


You
may try to introduce pressure (using it incorrectly, of course) as a
distraction, since it has not been mentioned before, but it won't
help.

[Pressure is force/area. You meant force.

It makes no difference in this context, a qualitative analysis. Is the
area changing, in such a way that it changes the conclusions and we
have to worry? In fact, pressure not force is what causes discomfort.
You are taking on a non-issue to get exorcised about because you prefer
not to deal with the real ones.

The fact remains, as I have pointed out continuously, that if he has
too much weight on his hands, he should flatten out the seat/saddle
first, and if that doesn't do enough then he should move the saddle
back. There is no situation in which moving the saddle forward will do
anything other than increase the weight on the hands.

Interestingly in your first post you also supplied this great wisdom:

"While the lowered handlebars may certainly be uncomfortable for many
people, it has little effect on the amount of weight on the
handlebars."

This is laughable. Sitting up or bent over, it's all the same. Right.


[long warm-up ad hominems deleted]


any
reasonably competent audience, you could be discredited and dismissed
You claim to understand physics, yet in another thread you suggest
that the proper way to analyze a problem that has both rotating and
translating objects would be to use both frames of reference
simultaneously. If you really had any idea of what you were talking
about you would know that this is absurd, since the whole concept of a
frame of reference means to choose a SINGLE convenient set of
coordinates in which to frame and solve the problem.

Frankly, I've come to suspect that your purpose here is as a troll.
Your posts are a disservice to the people here who are honestly trying
to understand things better.

I've been far too charitable with you.

I don't need your charity, but if I had taken your route long ago I
would not have been so charitable with you. For example, when you
talked about "our physics graduate students" to make yourself sound
more important. I wasn't fooled and I don't think anyone else was
either.

I see you have a sort of hypothetical knowledge of mechanics but not
the real thing. In particular, you have never gotten down to brass
tacks and actually solved for the dynamics of a multi-link system. If
you had you would not have made the incorrect claim about the single
frame of reference. Open any reference work in the mechanics of such
systems and you will see the pretty pictures with exactly the ground
and moving coordinate systems, and the equations which refer to them.
This is standard practice and it is how people really solve such
problems. But that is not your goal either.

The fact is that you have been posing since your first insult to me in
this thread and I see that the fact that I called you on it has not
gotten out from under your skin. It doesn't reflect well on either your
intellect or your personality.

Maybe the problem is in your saddle position. Is it on your bike? That
would explain a lot. Try pulling that pole out from up there, it might
help you.

"Jim Adney" wrote in message
...
On Tue, 26 Jul 2005 11:14:54 -0700 "Tom Nakashima"
wrote:

The reason for keeping
the seat level, is that I can ride closer to the nose of the saddle or
what
the old-timers called "riding on the rivet" on long straight-aways, when
riding at a fast pace.

I had never heard this expression before it was mentioned during OLN's
coverage of the TdF. In that comment they seemed to suggest that it
implied that the rider was tired. That doesn't make sense to me. If it
makes sense to you can you explain it to me?

Or did I catch the OLN comment wrong?

It seems to me that sliding forward on the saddle would be an easy way
of shifting your CM forward a bit, which would be useful, as you
imply, when riding hard.

Sounds like you may have caught it wrong...
Aside from a long breakaway in the Tour, If a cyclist is tired, they
probably wouldn't be riding on the rivet. Also doesn't sound like you ride
at a fast pace on the flats or else you would have already experimented with
this...your last paragraph suggest this.

In climbing I slide more to the rear of the saddle, while in a fast pace on
the flats I slide towards the front of the saddle. All other times I'm in my
comfortable sweet spot on the saddle which is around center. With the nose
of the saddle tilted up, it feels slightly uncomfortable riding near the
front of the saddle.

The objective for the flat saddle is that you have more options, but as I
mentioned, if you have ridden on your saddle for sometime, it develops a
concave in the center. There used to be a saddle on the market called the
Concor made by Selle San Marco which had a built in concave. Many cyclist
liked this saddle because it kept you from sliding and could have aided a
cyclist in climbing. Others didn't care for it because it kept the cyclist
in one place.
http://www.bikepro.com/products/sadd...ncor_sprnt.jpg
-tom

Tom Nakashima wrote:
T here used to be a saddle on the market called the
Concor made by Selle San Marco which had a built in concave. Many cyclist
liked this saddle because it kept you from sliding and could have aided a
cyclist in climbing. Others didn't care for it because it kept the cyclist
in one place.
http://www.bikepro.com/products/sadd...ncor_sprnt.jpg
-tom

The Concor Lite is the same general shape but less exaggerated, and is
the one Lance Armstrong uses, as well as many others:
http://tinyurl.com/8yubg
http://tinyurl.com/82ju7
I have one too but haven't used it in about half a decade since I
prefer the Brooks Pro..

"Jim Adney" wrote in message
...
On Tue, 26 Jul 2005 13:26:44 -0600 wrote:


I've always been annoyed by the fact that most of the time my rear
foot is just taking a "free lift" up the backside of the stroke...


Free lift or not, I figure it's all fair enough. While my upstroke is quite the
slacker when I ride the bike, it pays it's dues when I walk. When walking, it's
the downstroke foot that seems to always be takiing a free ride, as though it's
content to let gravity do all the work.


How well do most of you out there do? Can you consistently keep all
weight off the upstroke foot?


No, there most always seems to be some weight on the upstroke foot for me. So I
just relax and let the downstroke leg do the lifting, so to speak. As unfair as
this may seem to be, and as much as I've tried to intervene like a support
enforcement officer going after a deadbeat parent owing back child-support, by
the time the best of my thinking gets on the case, the upstroke foot has become
the downstroke foot and I'm caught barking up the wrong tree. Or down the wrong
crank arm, as it were.


I find climbing to be different. There I will consistently pull up on
the upstroke. How about you?


Yes, climbing is way different! I figure it's all from gravity getting it's
payback for all those free-riding upstrokes on the flats! Ouch, it's so much
more difficult going uphill that I have to work a lot harder. Downstroke,
upstroke -- it's just plain hard work, especially in the mountains. Anyway,
that's how it is for me.

Mykal Crooks
Seattle, WA

On Fri, 22 Jul 2005 17:34:39 +0000 (UTC) (C) wrote:

Do you honestly believe that you can put yourself into a normal riding
position, and then while coasting, lift your hands slightly off the
bars (no other change in body position allowed) and coast no-hands for
a sustained period?

Then our riding positions are considerably different. I tried it, too,
and I can't.

Sounds like your seat is too far forward or tilted down too much.

Please try this yourself and let me know whether you can do it or not.
So far, unless I've missed someone, King George is the only one whose
saddle position allows this.

The test can be done standing still, if you can get someone to hold
the bike upright while you try. Do it in a doorway, if possible.
Remember, drop bars, normal drop bar riding position, level ground, no
torque on the pedals during the test. Can you lift your hands off the
bars and keep them off with no tendency to slip forward off the
saddle?

I'd like to get as many data points as possible.

thanks,

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
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