"Crank forward" bikes get mainstream press

Matt O'Toole said:

Wired has an article this week on "crank forward" bikes -- ones with the
seat low and behind the saddle so the rider can reach the ground with
their feet:

http://www.wired.com/news/technology/0,70174-0.html?tw=wn_index_30

ITYM "the seat low and well behind the BB".

The Rans Zenetik pictured wouldn't interest me. The radical seatpost
angle means that the strain on that component and on the seat tube of
the frame is rather larger than normal, I question whether one could
stand to pedal, it would be difficult for the rider to quickly lift
off of the seat for traversal of bumps, and it has squirrel-jam
wheels. I like the long wheelbase, but that's about all.

--
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Werehatrack said:

Matt O'Toole said:

Wired has an article this week on "crank forward" bikes -- ones with the
seat low and behind the saddle so the rider can reach the ground with
their feet:

http://www.wired.com/news/technology/0,70174-0.html?tw=wn_index_30

ITYM "the seat low and well behind the BB".

The Rans Zenetik pictured wouldn't interest me.

"RANS" should always be all capital letters.

Quoted message said:

The radical seatpost angle means that the strain on that component and on the seat tube
of the frame is rather larger than normal,

The cantilevered portion of the seat tube is fairly short. As for
strain on the seat post, that depends not only on the load applied, but
the moment of inertia of its cross-section.

Remember, P/A + My/I.

Quoted message said:

I question whether one could
stand to pedal, it would be difficult for the rider to quickly lift
off of the seat for traversal of bumps, and it has squirrel-jam
wheels. I like the long wheelbase, but that's about all.

There are pictures of riders standing on the Zenetik.

The standard RANS Zenetik Tour has [gasp] 36-spoke, 3-cross wheels:
<http://www.ransbikes.com/zenetik%20tour.htm>.

--
Tom Sherman

In article <[email hidden]>, Werehatrack

Quoted message said:

Matt O'Toole said:

Wired has an article this week on "crank forward" bikes -- ones with the
seat low and behind the saddle so the rider can reach the ground with
their feet:

http://www.wired.com/news/technology/0,70174-0.html?tw=wn_index_30

ITYM "the seat low and well behind the BB".

The Rans Zenetik pictured wouldn't interest me. The radical seatpost
angle means that the strain on that component and on the seat tube of
the frame is rather larger than normal, I question whether one could
stand to pedal, it would be difficult for the rider to quickly lift
off of the seat for traversal of bumps, and it has squirrel-jam
wheels. I like the long wheelbase, but that's about all.

RANS has engineered a response to (your concern) the direction of load
placed upon the seat-tube/seatpost; it's explained, albeit vaguely, in
one of its 'articles' at [http://www.ransbikes.com/ITR32.htm].

Further, RANS asserts that the position of the crank vis other controls
negates the need to stand on the pedals: "With the crank forward more
than a conventional bike and the bars placed low, just above the knees,
you can pull yourself down into the pedals. Using this technique it is
easy to apply more than your weight to the pedals, which is all
standing on the pedals will provide..." Hmmm.

Any impartial, long term, trials conducted on these bikes?

Luke

Matt O'Toole said:

Wired has an article this week on "crank forward" bikes -- ones with the
seat low and behind the saddle so the rider can reach the ground with
their feet:

http://www.wired.com/news/technology/0,70174-0.html?tw=wn_index_30

Matt O.

Now all we need is 'citys' where they can be ridden...

On Mon, 13 Feb 2006 04:37:26 -0500, Luke <[email hidden]>

Quoted message said:

In article <[email hidden]>, Werehatrack
<[email hidden]> wrote:

Quoted message said:

Quoted message said:

The Rans Zenetik pictured wouldn't interest me. The radical seatpost
angle means that the strain on that component and on the seat tube of
the frame is rather larger than normal, I question whether one could
stand to pedal, it would be difficult for the rider to quickly lift
off of the seat for traversal of bumps, and it has squirrel-jam
wheels. I like the long wheelbase, but that's about all.

RANS has engineered a response to (your concern) the direction of load
placed upon the seat-tube/seatpost; it's explained, albeit vaguely, in
one of its 'articles' at [http://www.ransbikes.com/ITR32.htm].

There's also the matter of the posterior jounce factor when you hit a
bump. I greatly prefer to be out of the saddle when I hit rough
spots; my legs are much better at soaking up that motion than any
saddle I've ever encountered. (The only 'bents I've ridden, OTOH, had
more of a seat than a saddle, and did a better job of spreading the
load.)

Quoted message said:

Further, RANS asserts that the position of the crank vis other controls
negates the need to stand on the pedals: "With the crank forward more
than a conventional bike and the bars placed low, just above the knees,
you can pull yourself down into the pedals. Using this technique it is
easy to apply more than your weight to the pedals, which is all
standing on the pedals will provide..." Hmmm.

See my earlier comments; there's more than one reason to get out of
the saddle, and the "pull down" factor cited has its own set of
problems.

--
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Qui si parla Campagnolo said:

Matt O'Toole said:

Wired has an article this week on "crank forward" bikes -- ones with the
seat low and behind the saddle so the rider can reach the ground with
their feet:

http://www.wired.com/news/technology/0,70174-0.html?tw=wn_index_30

Matt O.

Now all we need is 'citys' where they can be ridden...

Indiana, perhaps?
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Qui si parla Campagnolo said:

Now all we need is 'citys' where they can be ridden...

Isn't this the truth!

It's a shame how the Southeast is drawing so many retirees to new
subdivisions where they'll be prisoners in their own homes once their
driving days are over.

The sick thing is that this region, in this day and age, has probably the
largest spread ever between construction cost and selling price, so
there's plenty of margin for developers to be required to provide land,
infrastructure, and appropriate design for bike/ped access. Also, I'm
sure all the new property tax revenue is more than enough to pay for 2'
wider lanes on all the new suburban arterials, as well as older ones that
are being "widened."

Matt O.

Werehatrack said:

There's also the matter of the posterior jounce factor when you hit a
bump. I greatly prefer to be out of the saddle when I hit rough
spots; my legs are much better at soaking up that motion than any
saddle I've ever encountered. (The only 'bents I've ridden, OTOH, had
more of a seat than a saddle, and did a better job of spreading the
load.)

Most people who would be in the market for this kind of bike are not the
ones who would understand getting out of the saddle to avoid bumps.

No one seems to have noticed the real reason why they can claim that their
bikes are so good climbing hills. It's not, per se, the seat tube angle,
but the saddle that has that ridge in the back to provide leverage.
I believe such saddles are illegal for racing since they really do
provide an advantage.

--

David L. Johnson

__o | And what if you track down these men and kill them, what if you
_`\(,_ | killed all of us? From every corner of Europe, hundreds,
(_)/ (_) | thousands would rise up to take our places. Even Nazis can't
kill that fast. -- Paul Henreid (Casablanca).

Werehatrack said:

Matt O'Toole said:

Wired has an article this week on "crank forward" bikes -- ones with the
seat low and behind the saddle so the rider can reach the ground with
their feet:

http://www.wired.com/news/technology/0,70174-0.html?tw=wn_index_30

ITYM "the seat low and well behind the BB".

The Rans Zenetik pictured wouldn't interest me....

The market for the crank forward (CF) semi-upright bicycles is
typically not the regular road bike rider who is satisfied with his/her
bicycle, but those who have comfort issues with conventional road bikes
[1] but find recumbents overly different, complex or expensive.

If the CF bikes get people out riding on a regular basis who would
otherwise not do so, this is a good thing (unless one is an insecure
person who has to build himself/herself up by denigrating those who
ride and wear anything but the professional team replica clothing and
equipment).

[1] Most new riders, or even regular road bike riders after a layoff
(e.g. winter).

--
Tom Sherman

These bikes just beg for suspension on the seat post. Put a tractor
seat and steering wheel on the bike, a great big lugged wheel on the
back, and paint it red! I'll be the first in line to buy one!

One really good thing about the bike is that I think that they've
finally solved the problem of going over the bars. On my old GT
commuter bike once a month or so I'd pull a stoppy when some
cell-phone-talking idiot or inbred upper-class twit would pull out in
front of me. That wouldn't happen on one of these, because they don't
seem to be built for speed and have the center of gravity well behind
the rear wheel.

Quoted message said:

[they] have the center of gravity well behind
the rear wheel.

Not quite.

--
Phil, Squid-in-Training

Luke wrote:
---snip---

"With the crank forward more

Quoted message said:

than a conventional bike and the bars placed low, just above the knees,
you can pull yourself down into the pedals. Using this technique it is
easy to apply more than your weight to the pedals, which is all
standing on the pedals will provide

---/snip---

Funny...when I'm climbing, sprinting (ha!), or otherwise accelerating,
I seem to be "pull[ing] myself down into the pedals" quite effectively.
Look at any road biker's forearms during these actions if you have any
questions. I'd guess that far more than the rider's weight is being
applied to the pedals (but admittedly, do not have the math to back it
up).

SYJ

SYlly Jenkins said:

Quoted message said:

"With the crank forward more than a conventional bike and the bars
placed low, just above the knees, you can pull yourself down into
the pedals. Using this technique it is easy to apply more than your
weight to the pedals, which is all standing on the pedals will
provide

Quoted message said:

Funny... when I'm climbing, sprinting (ha!), or otherwise
accelerating, I seem to be "pull[ing] myself down into the pedals"
quite effectively. Look at any road biker's forearms during these
actions if you have any questions. I'd guess that far more than the
rider's weight is being applied to the pedals (but admittedly, do
not have the math to back it up).

It may "seem" that way to you but in fact you are not pulling up on
the bars when sprinting but rather up on one side and down on the
other to counter some of the leg forces on the bicycle. When
climbing, body weight is behind the pedals and by pulling back on the
bars brings body weight that otherwise rests on the saddle to bear on
the pedals.

I think you'll find that not much "work" is being done by the arms but
that they serve a holding or stabilizing effect for pedaling. Work
after all is force times distance and the arms don't move any distance
with force. You'll notice that when pedaling standing on a hill, the
arms only change position at the top/bottom of the pedal stroke with
no substantial force and no pedaling torque is taking place.

Jobst Brandt

I guess I should have said center of gravity well behind the front
wheel, because that's what I meant. But you knew that.

Dans le message de news:[email hidden],
[email hidden] <[email hidden]> a
réfléchi, et puis a déclaré :

Quoted message said:

SYlly Jenkins said:

Quoted message said:

"With the crank forward more than a conventional bike and the bars
placed low, just above the knees, you can pull yourself down into
the pedals. Using this technique it is easy to apply more than your
weight to the pedals, which is all standing on the pedals will
provide

Quoted message said:

Funny... when I'm climbing, sprinting (ha!), or otherwise
accelerating, I seem to be "pull[ing] myself down into the pedals"
quite effectively. Look at any road biker's forearms during these
actions if you have any questions. I'd guess that far more than the
rider's weight is being applied to the pedals (but admittedly, do
not have the math to back it up).

It may "seem" that way to you but in fact you are not pulling up on
the bars when sprinting but rather up on one side and down on the
other to counter some of the leg forces on the bicycle. When
climbing, body weight is behind the pedals and by pulling back on the
bars brings body weight that otherwise rests on the saddle to bear on
the pedals.

I think you'll find that not much "work" is being done by the arms but
that they serve a holding or stabilizing effect for pedaling. Work
after all is force times distance and the arms don't move any distance
with force. You'll notice that when pedaling standing on a hill, the
arms only change position at the top/bottom of the pedal stroke with
no substantial force and no pedaling torque is taking place.

Jobst Brandt

MYTH AND FALSEHOOD, KIND SIR.

Interesting bikes. I guess they make more sense than comfort bikes, but
it bugs the hell out of me any time someone says road bikes are
uncomfortable. If you build your fitness and get a good fit, they are
as comfortable anything else. I just don't have any problems on my road
bike after or during a ride.

Matt O'Toole said:

Wired has an article this week on "crank forward" bikes -- ones with the
seat low and behind the saddle so the rider can reach the ground with
their feet:

http://www.wired.com/news/technology/0,70174-0.html?tw=wn_index_30

Matt O.

In article <[email hidden]>, Sandy

Quoted message said:

Quoted message said:

It may "seem" that way to you but in fact you are not pulling up on
the bars when sprinting but rather up on one side and down on the
other to counter some of the leg forces on the bicycle. When
climbing, body weight is behind the pedals and by pulling back on the
bars brings body weight that otherwise rests on the saddle to bear on
the pedals.

I think you'll find that not much "work" is being done by the arms but
that they serve a holding or stabilizing effect for pedaling.

Judging by the anatomies of track cyclists[1] the degree of strength
required of the arms to 'stabilize' the rider is commensurate with the
power in the legs. So even though it may said that the arms don't
contribute much, clearly they can limit the amount of pedalling power
otherwise available in the legs.

Strictly on a subjective level, from scrutinizing my own pedalling
habits, the percentage of the energy the arms contribute compared to
the legs, seems variable and contingent on pedalling style. For
instance, either in or out of the saddle, if my trailing leg doesn't
pull on the upstroke, the arms must provide the extra leverage -
occasionally they burn as they've undergone a set of biceps curls. In
these cases the amount of energy required of the arms acting in
counterpoint to the legs sure *feels* significant. No quantitative
measurments available though.

Quoted message said:

Quoted message said:

Work
after all is force times distance and the arms don't move any distance
with force. You'll notice that when pedaling standing on a hill, the
arms only change position at the top/bottom of the pedal stroke with
no substantial force and no pedaling torque is taking place.

Jobst Brandt

Quoted message said:

MYTH AND FALSEHOOD, KIND SIR.

In part or total? Please elaborate.

Luke

1. Pic of Marty Nothstein (in a road race?!)
http://www.jsmcelvery.com/photos/2004/road/nyc/nyc04nothstein1.jpg

Lucas Iragusa said:

Quoted message said:

It may "seem" that way to you but in fact you are not pulling up on
the bars when sprinting but rather up on one side and down on the
other to counter some of the leg forces on the bicycle. When
climbing, body weight is behind the pedals and by pulling back on
the bars brings body weight that otherwise rests on the saddle to
bear on the pedals.

Quoted message said:

Quoted message said:

I think you'll find that not much "work" is being done by the arms
but that they serve a holding or stabilizing effect for pedaling.

Quoted message said:

Judging by the anatomies of track cyclists[1] the degree of strength
required of the arms to 'stabilize' the rider is commensurate with
the power in the legs. So even though it may said that the arms
don't contribute much, clearly they can limit the amount of pedaling
power otherwise available in the legs.

Not so, the arms are pushing the top of the frame to the side,
opposing the pedal imbalance that is the pedal force times the lateral
distance from the centerline of tire contact. The arms in contrast
have the leverage of the hand-to-pedal distance which is many times
greater besides which the force is relatively static, so no "work" is
being performed.

Quoted message said:

Strictly on a subjective level, from scrutinizing my own pedaling
habits, the percentage of the energy the arms contribute compared to
the legs, seems variable and contingent on pedaling style. For
instance, either in or out of the saddle, if my trailing leg doesn't
pull on the upstroke, the arms must provide the extra leverage -
occasionally they burn as they've undergone a set of biceps curls.
In these cases the amount of energy required of the arms acting in
counterpoint to the legs sure *feels* significant. No quantitative
measurements available though.

You use the term "energy" which doesn't describe what is being done.
If you look at the arms of some of the great climbers, you will not
that they are trivially skinny with not much muscle, even though some
ride an entire hill climb out of the saddle. See Charley Gaul, Lucien
van Impe, Frederico Bahamontes, and not to forget Jean Robic skinny as
they come except for the legs.

http://www.memoire-du-cyclisme.net/palmares/robic_jean.php

Quoted message said:

Quoted message said:

Work after all is force times distance and the arms don't move any
distance with force. You'll notice that when pedaling standing on
a hill, the arms only change position at the top/bottom of the
pedal stroke with no substantial force and no pedaling torque is
taking place.

Jobst Brandt

Dans le message de news:[email hidden],
Luke <[email hidden]> a réfléchi, et puis a déclaré :

Quoted message said:

In article <[email hidden]>, Sandy
<[email hidden]> wrote:

Quoted message said:

Quoted message said:

Quoted message said:

Work
after all is force times distance and the arms don't move any
distance with force. You'll notice that when pedaling standing on
a hill, the arms only change position at the top/bottom of the
pedal stroke with no substantial force and no pedaling torque is
taking place.

Jobst Brandt

Quoted message said:

MYTH AND FALSEHOOD, KIND SIR.

In part or total? Please elaborate.

To take in the simplest global perception : if we measure leg force by
positing that the force is generated entirely between hip and foot, then
when the hip is liberated from its anchor, the force exerted is throughout
the body, from hand to foot. I imagine someone may have measured this, and
maybe someone can cite to such a study.

But to suggest that the "stabilizing" force is negligible (another favored
RBT term), then I challenge the proponent of that theory to ride uphill with
significant leg force, bereft of the seated position (en danseuse, as we say
over here), and do it no hands. If that can be done, I will make voluminous
public apologies right here. On the other hand, I am sure that the
well-equipped scientists here can cobble up some sort of measurement device
to gauge the pressures exerted by hands on bars during either a sprint or a
strong attack in the mountains.

I won't evade an apology in the event that I am shown not to have made a
fair accusation. Thanks.
--
Bonne route !

Sandy
Verneuil-sur-Seine FR