The zero wind tunnel option for serious cyclists

graham

"Andre Jute" <fiultra1@yahoo.com> wrote in message
news:fb50243a-97b8-4837-9af4-4ad13976a25b@w4g2000prd.googlegroups.com...
On May 10, 6:03 pm, "graham" <h2gt2g42-n...@yahoo.co.uk> wrote:
> "Andre Jute" <fiult...@yahoo.com> wrote in message
>
> news:85d965f3-356f-453a-a264-0308b7b2414f@k1g2000prb.googlegroups.com...
>
> joseph.santanie...@gmail.com <joseph.santanie...@gmail.com> wrote:
[Snip]

Either way I'm sure we'll advance our knowledge and have a spot of fun
doing it. Nice meeting you, Graham.

So long as it is fun then that's fine by me. There are far too many
"stressful" debates on this news group. You will by now have seen my
previous reply but to answer your query about my methodology it is all set
out in my original reply to Joseph. I have not attempted in the modelling I
have done to seperate out frontal area from drag coefficient but merely to
have derived their product from the formula I offered Joseph. I have toyed
with the idea of using photography to obtain an approximate measure of my
frontal area but never got round to it as the numbers for Cd x A I have
derived from my tests seem to be quite close which is what matters. As I see
it even if I could measure my frontal area how sure could I be of the value
of Cd to multiply it by?

Graham.

Robert Chung

On May 10, 3:51 pm, "graham" <h2gt2g42-n...@yahoo.co.uk> wrote:

> In Joseph's case then the down hill method whilst not delivering "precision"
> will allow him to do comparative tests on his position on the bike

If one were interested in doing comparative tests then precision would
be key. On the other hand, if the interest is in using CdA to get a
reasonable estimate of power, accuracy is more important.

Tom Sherman

Andre Jute wrote:
> [...]
> My guess for cyclists of Cd = 0.50 which bothers you still seems
> reasonable to me, possibly on the low side of a conservative estimate.
> An automobile must be awesomely well developed to reach a Cd of 0.3.

My 1994 Honda Civic Si had a reported Cd of 0.29.

> The human body is simply not an aerodynamic device, and in the
> Aerodynamicists' Club hangs a Wanted Criminal poster for the man who
> designed the safety bicycle.[...]

Careful now, the dark side is calling.

Here is a model of bicycle that reportedly (based on recorded speed and
power meter data) has a Cd of less than 0.08:
<http://www.ent.ohiou.edu/~et181/hpv/lisa_Vetterlein.jpg>. Of course, it
is not usable on anything but a close course in low wind conditions.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

jobst.brandt@stanfordalumni.org

Tom Sherman wrote:

>> [...]
>> My guess for cyclists of Cd = 0.50 which bothers you still seems
>> reasonable to me, possibly on the low side of a conservative
>> estimate. An automobile must be awesomely well developed to reach
>> a Cd of 0.3.

> My 1994 Honda Civic Si had a reported Cd of 0.29.

>> The human body is simply not an aerodynamic device, and in the
>> Aerodynamicists' Club hangs a Wanted Criminal poster for the man
>> who designed the safety bicycle.[...]

> Careful now, the dark side is calling.

> Here is a model of bicycle that reportedly (based on recorded speed
> and power meter data) has a Cd of less than 0.08:

http://www.ent.ohiou.edu/~et181/hpv/lisa_Vetterlein.jpg

> Of course, it is not usable on anything but a close course in low
> wind conditions.

This thread and the one about optimal spoke pattern is depressing to
me. It seems RBT has drifted into the "me too" syndrome of fans of
professional athletes. No one seems interested in enjoying bicycling
for itself but rather looking for ways of achieving world records.

Following that direction, "Bicycling in America" becomes more a way of
life:

http://draco.acs.uci.edu/rbfaq/FAQ/6.1.html

Wind effect has always been interesting in bicycling, but that is not
what this thread is about. To fill that gap for wind effects:

http://www.sheldonbrown.com/brandt/wind.html

Get out and enjoy the beauty of bicycling and forget about beating the
next guy in racing with special and more expensive equipment. There's
much more to bicycling than competition. In fact there's more to life
than the sports page.

For example:

http://www.paloaltobicycles.com/alps_photos.html

Jobst Brandt

joseph.santaniello@gmail.com

On May 11, 5:41*am, jobst.bra...@stanfordalumni.org wrote:

> This thread and the one about optimal spoke pattern is depressing to
> me. *It seems RBT has drifted into the "me too" syndrome of fans of
> professional athletes. *No one seems interested in enjoying bicycling
> for itself but rather looking for ways of achieving world records.

I quite enjoy cycling just for the hell of it. That's why I do dumb
things like ride track bikes around on hilly roads. It's fun. But
racing is fun too, and in my case would be quite a bit more fun if I
didn't get dropped from every road race, or finish last in every time
trial. To acheive this I could either move someplace where there are
slower racers, or I can eliminate waste from my equipment and train to
become stronger. I chose the latter two. And that gives an enjoyment
in itself.

> Get out and enjoy the beauty of bicycling and forget about beating the
> next guy in racing with special and more expensive equipment. *There's
> much more to bicycling than competition. *In fact there's more to life
> than the sports page.

It doesn't have to be expensive. That TT bike in my pics has a $139
frame and used Sora equipment. Hardly expensive!

But I agree there is more than competition. For me competition is just
one facet. And as such, I cannot fathom why some of the folks I ride
with spend hours and hours at health clubs in the winter riding
stationary bikes.

> For example:
>
> http://www.paloaltobicycles.com/alps_photos.html

Beautiful.

Joseph

Rik O'Shea

On 10 May, 17:59, Tim McNamara <tim...@bitstream.net> wrote:

>
> Not so much in terms of "publishing." You've posted a Web page is all;
> that's different than publishing in the scientific sense of the word.

"Posted" maybe more accurate in this context but there does seem to
be quite a few books published by Mr Jute (who I assume is the
original poster). I dont think there are too many posters to this
forum who can claim the same.
http://www.amazon.com/exec/obidos/s...or=Andre%20Jute

Andre Jute

On May 11, 4:05*am, Tom Sherman <sunsetss0...@REMOVETHISyahoo.com>
wrote:
> Andre Jute wrote:
> > [...]
> > My guess for cyclists of Cd = 0.50 which bothers you still seems
> > reasonable to me, possibly on the low side of a conservative estimate.
> > An automobile must be awesomely well developed to reach a Cd of 0.3.
>
> My 1994 Honda Civic Si had a reported Cd of 0.29.

I'll take your word for it, Tom. Now name ten more cars that ever saw
a showroom with a Cd of 0.3 or under.

> > The human body is simply not an aerodynamic device, and in the
> > Aerodynamicists' Club hangs a Wanted Criminal poster for the man who
> > designed the safety bicycle.[...]
>
> Careful now, the dark side is calling.
>
> Here is a model of bicycle that reportedly (based on recorded speed and
> power meter data) has a Cd of less than 0.08:
> <http://www.ent.ohiou.edu/~et181/hpv/lisa_Vetterlein.jpg>.

Now we know what happened to Ma Sherman's molds for the State Fair
prizewinning handed monster jellies.

>Of course, it
> is not usable on anything but a close course in low wind conditions.

The shortage of defined edges looks like a textbook case of
aerodynamic instability. I wouldn't mind having a go in it, though,
even better, to have it for a week or a month to run some tests in a
quiet valley I know with a lane in the bottom.

Andre Jute
http://members.lycos.co.uk/fiultra/...%20CYCLING.html

Clive George

"Andre Jute" <fiultra1@yahoo.com> wrote in message
news:b6b31009-2087-4f84-bdfb-e293367bb670@w1g2000prd.googlegroups.com...

>I'll take your word for it, Tom. Now name ten more cars that ever saw
>a showroom with a Cd of 0.3 or under.

Far too easy...

Audi 100 was 0.3 in 1982.
Vauxhall/Opel Calibra
Honda Insight
Porsche Boxster
BMW 8-series
Honda CRX
Hyundai Sonata
Toyota Camry
Saab 9-3
Lotus Elite
Lexus LS400 and LS430
Audi A2
S-class Mercedes

Andre Jute

On May 11, 8:17*am, "joseph.santanie...@gmail.com"
<joseph.santanie...@gmail.com> wrote:
> On May 11, 5:41*am, jobst.bra...@stanfordalumni.org wrote:
>
> > This thread and the one about optimal spoke pattern is depressing to
> > me. *It seems RBT has drifted into the "me too" syndrome of fans of
> > professional athletes. *No one seems interested in enjoying bicycling
> > for itself but rather looking for ways of achieving world records.
>
> I quite enjoy cycling just for the hell of it. That's why I do dumb
> things like ride track bikes around on hilly roads. It's fun. But
> racing is fun too, and in my case would be quite a bit more fun if I
> didn't get dropped from every road race, or finish last in every time
> trial. To acheive this I could either move someplace where there are
> slower racers, or I can eliminate waste from my equipment and train to
> become stronger. I chose the latter two. And that gives an enjoyment
> in itself.
>
> > Get out and enjoy the beauty of bicycling and forget about beating the
> > next guy in racing with special and more expensive equipment. *There's
> > much more to bicycling than competition. *In fact there's more to life
> > than the sports page.
>
> It doesn't have to be expensive. That TT bike in my pics has a $139
> frame and used Sora equipment. Hardly expensive!
>
> But I agree there is more than competition. For me competition is just
> one facet. And as such, I cannot fathom why some of the folks I ride
> with spend hours and hours at health clubs in the winter riding
> stationary bikes.
>
> > For example:
>
> >http://www.paloaltobicycles.com/alps_photos.html
>
> Beautiful.
>
> Joseph

Bit hypocritical of Jobst to decry our modest efforts after he himself
reducted a famous article for go-faster merchants. See:
http://www.sheldonbrown.com/brandt/wind.html

Thing is, though, I agree with him. I took up cycling for my heatlth
and discovered I enjoy it for its own sake, and now consider a day
wasted on which I cannot cycle for some reason.

Andre Jute
Often wrong, never insincere

joseph.santaniello@gmail.com

On May 12, 4:43*pm, Andre Jute <fiult...@yahoo.com> wrote:

> I like the Compton idea of a large warehouse... Makes me wonder if one
> could liberate some traffic cones and diversion signs and claim a
> tunnel through a mountain or under a river for cycling tests for a few
> hours early one morning before the authorities get their brains in
> gear...

I have considered this. But around here at least, there is often a
stiff breeze in the tunnels. It may be constant however.

This one ought to do:

http://en.wikipedia.org/wiki/Image:TRS_070405_016.jpg

It's 7.2km long under a narrow section of Oslo Fjord. The gradient is
7% on each side.

There is so little traffic there, I'll bet you could dispense with the
cones.

Talk about a foolish endeavour. The tunnel cost an astronomical amount
of money, and was built to alleviate some of the heavy traffic that
goes through Oslo (and to service a new airport which never happened
because they decided to build it someplace else!). But it is so steep
that trucks use more fuel taking the tunnel shotrcut than taking the
long route through Oslo (according to my father in law who is in the
transport business here).

Joseph

Rik O'Shea

On 12 May, 18:14, "joseph.santanie...@gmail.com"
<joseph.santanie...@gmail.com> wrote:
> On May 12, 4:43 pm, Andre Jute <fiult...@yahoo.com> wrote:
>
> > I like the Compton idea of a large warehouse... Makes me wonder if one
> > could liberate some traffic cones and diversion signs and claim a
> > tunnel through a mountain or under a river for cycling tests for a few
> > hours early one morning before the authorities get their brains in
> > gear...
>
> I have considered this. But around here at least, there is often a
> stiff breeze in the tunnels. It may be constant however.
>
> This one ought to do:
>
> http://en.wikipedia.org/wiki/Image:TRS_070405_016.jpg
>
> It's 7.2km long under a narrow section of Oslo Fjord. The gradient is
> 7% on each side.
>
> There is so little traffic there, I'll bet you could dispense with the
> cones.
>
> Talk about a foolish endeavour. The tunnel cost an astronomical amount
> of money, and was built to alleviate some of the heavy traffic that
> goes through Oslo (and to service a new airport which never happened
> because they decided to build it someplace else!). But it is so steep
> that trucks use more fuel taking the tunnel shotrcut than taking the
> long route through Oslo (according to my father in law who is in the
> transport business here).
>
> Joseph


I used the Dublin port tunnel just before it was opened to traffic for
a very successful set of CdA field tests (it was just about to be used
for a 10 k running race).
Its perfectly flat, at sea level, over 4 km long and there is zero
wind in it!

http://en.wikipedia.org/wiki/ImagePT_inside.jpg

joseph.santaniello@gmail.com

On May 12, 3:58*pm, "Clive George" <cl...@xxxx-x.fsnet.co.uk> wrote:
> "Andre Jute" <fiult...@yahoo.com> wrote in message
>
> news:b6b31009-2087-4f84-bdfb-e293367bb670@w1g2000prd.googlegroups.com...
>
> >I'll take your word for it, Tom. Now name ten more cars that ever saw
> >a showroom with a Cd of 0.3 or under.
>
> Far too easy...
>
> Audi 100 was 0.3 in 1982.
> Vauxhall/Opel Calibra
> Honda Insight
> Porsche Boxster
> BMW 8-series
> Honda CRX
> Hyundai Sonata
> Toyota Camry
> Saab 9-3
> Lotus Elite
> Lexus LS400 and LS430
> Audi A2
> S-class Mercedes

I kind of like the Smart Roadster (if it didn't have the crap
gearbox). It has 0.266.

If I get a new car it will probably be a Fiat Grande Punto which only
has 0.31, or an Alfa Romeo MiTo. Wouldn't want a car with a better CdA
than me!

Joseph

Robert Chung

On May 12, 10:23 am, "Rik O'Shea" <rikos...@yahoo.com> wrote:

> I used the Dublin port tunnel just before it was opened to traffic for
> a very successful set of CdA field tests (it was just about to be used
> for a 10 k running race).
> Its perfectly flat, at sea level, over 4 km long and there is zero
> wind in it!

Could you describe your test protocol and how you could tell that they
were very successful?

joseph.santaniello@gmail.com

On May 12, 7:23*pm, "Rik O'Shea" <rikos...@yahoo.com> wrote:
> On 12 May, 18:14, "joseph.santanie...@gmail.com"
>
>
>
> <joseph.santanie...@gmail.com> wrote:
> > On May 12, 4:43 pm, Andre Jute <fiult...@yahoo.com> wrote:
>
> > > I like the Compton idea of a large warehouse... Makes me wonder if one
> > > could liberate some traffic cones and diversion signs and claim a
> > > tunnel through a mountain or under a river for cycling tests for a few
> > > hours early one morning before the authorities get their brains in
> > > gear...
>
> > I have considered this. But around here at least, there is often a
> > stiff breeze in the tunnels. It may be constant however.
>
> > This one ought to do:
>
> >http://en.wikipedia.org/wiki/Image:TRS_070405_016.jpg
>
> > It's 7.2km long under a narrow section of Oslo Fjord. The gradient is
> > 7% on each side.
>
> > There is so little traffic there, I'll bet you could dispense with the
> > cones.
>
> > Talk about a foolish endeavour. The tunnel cost an astronomical amount
> > of money, and was built to alleviate some of the heavy traffic that
> > goes through Oslo (and to service a new airport which never happened
> > because they decided to build it someplace else!). But it is so steep
> > that trucks use more fuel taking the tunnel shotrcut than taking the
> > long route through Oslo (according to my father in law who is in the
> > transport business here).
>
> > Joseph
>
> I used the Dublin port tunnel just before it was opened to traffic for
> a very successful set of CdA field tests (it was just about to be used
> for a 10 k running race).
> Its perfectly flat, at sea level, over 4 km long and there is zero
> wind in it!
>
> http://en.wikipedia.org/wiki/ImagePT_inside.jpg

What did you test?

Joseph