Need those brains again

[Bob]

So if a cross-wind has no or little effect on forward motion does the
banking of a velodrome effect lap times (other than providing adequate
centipetal force)?
And if not then what makes one velodrome faster than another for a
particular event?
I suspect the differences are negligible.

 

[Tom Orr]

"Bob" <[email protected]> wrote in message
news:[email protected]...
> So if a cross-wind has no or little effect on forward motion does the
> banking of a velodrome effect lap times (other than providing adequate
> centipetal force)?

I have no idea.

> And if not then what makes one velodrome faster than another for a
> particular event?

Apparently, height above sea-level.

Tom.

 

[Bryan]

So if a cross-wind has no or little effect on forward motion does the
banking of a velodrome effect lap times (other than providing adequate
centipetal force)?
And if not then what makes one velodrome faster than another for a
particular event?
I suspect the differences are negligible.

It's been a looooong time since I've done angular momentum poblems but from my recolections of the dim and distant past the banking allows the rider to effectively continue in a straight line, and thus their speed is maintained . The angle of the banking will effect how much of a 'straight line' the bend becomes. If all banking is the same angle then this is taken out of the equation.

The most common reason for one track being faster than another is what it's made of and the coating (varnish etc) applied. This can dramatically affect rolling resistance (cf wax on skies). Also is the track open air or enclosed as wind also has a dramatic effect

My question on all this is, since in a previous life I used to be a semi decent swimmer I could never work out why one pool was significantly faster than another, after all water density doesn;t vary *that* much.

Bryan

 

[Jeremy Collins]

On Fri, 20 May 2005 09:29:02 +0100, Bryan
<[email protected]> wrote:


> My question on all this is, since in a previous life I used to be a
> semi decent swimmer I could never work out why one pool was
> significantly faster than another, after all water density doesn;t vary
> *that* much.

P'raps the "faster" pool was built by contractors with cowboyish
tendencies, and was a couple of feet shorter than you thought it
was...?!


--
jc

 

[Richard]

Bryan wrote:
> I could never work out why one pool was
> significantly faster than another, after all water density doesn;t vary
> *that* much.

From what I recall, it is to do with the shape and size of the pool and
the lane separators which both affect the waves. Pools which damp the
waves are "faster".

R.

 

[Tony Raven]

Bryan wrote:
>
> My question on all this is, since in a previous life I used to be a
> semi decent swimmer I could never work out why one pool was
> significantly faster than another, after all water density doesn;t vary
> *that* much.
>

One was probably built on a slope so you were swimming downhill ;-)

--
Tony

"A facility for quotation covers the absence of original thought" Lord
Peter Wimsey (Dorothy L. Sayers)

 

[sean]

<[email protected]> wrote:
> My question on all this is, since in a previous life I used to be a
> semi decent swimmer I could never work out why one pool was
> significantly faster than another, after all water density doesn;t
vary
> *that* much.

P'raps the "faster" pool was built by contractors with cowboyish
tendencies, and was a couple of feet shorter than you thought it
was...?!

This really happened at Leeds 'International' pool !
It was discovered to be a few inches short after it was built.

It is true that deeper pools have more records set in them than
shallower pools though. Something to do with displacement?
Sean.

 

[Bob]

We're getting off the track here brains!

 

[Julesh]

Bob wrote:
> We're getting off the track here brains!
>
>
That's OK. A thread that was of no interest to me at the beginning has
been transformed by U.R.C into a thing of wonder and delight!


Julesh

 

[Alan Braggins]

In article <[email protected]>, sean wrote:
><[email protected]> wrote:
>> My question on all this is, since in a previous life I used to be a
>> semi decent swimmer I could never work out why one pool was
>> significantly faster than another, after all water density doesn;t
>vary
>> *that* much.

(With the exception of salt water pools.)


>It is true that deeper pools have more records set in them than
>shallower pools though. Something to do with displacement?

Waves travel slower in shallow water, so you have to do more work
to climb your own bow wave.

 

[Graham Dean]

> So if a cross-wind has no or little effect on forward motion
But it does - try a little observational science...

>does the banking of a velodrome effect lap times
I doubt it's a major impact - but the length of bend certainly does - try
fighting the track around
calshot...

> And if not then what makes one velodrome faster than another for a
> particular event?
*All* the other variables.

Graham

"Bob" <[email protected]> wrote in message
news:[email protected]...
> So if a cross-wind has no or little effect on forward motion does the
> banking of a velodrome effect lap times (other than providing adequate
> centipetal force)?
> And if not then what makes one velodrome faster than another for a
> particular event?
> I suspect the differences are negligible.
>
>

 

[Phil Clarke]

sean wrote:

> It is true that deeper pools have more records set in them than
> shallower pools though. Something to do with displacement?

you do have to fight more of the turbulence reflecting off the bottom

but is it likely that deeper pools are built at flasher venues? The sort
of venues commonly used for the events that attract top athletes who
break records?

 

[Tony Raven]

sean wrote:
>
> This really happened at Leeds 'International' pool !
> It was discovered to be a few inches short after it was built.
>

And I believe at Dundee where their Olympic pool turned out to be two
tile thicknesses short of the required length when it was finished.

--
Tony

"A facility for quotation covers the absence of original thought" Lord
Peter Wimsey (Dorothy L. Sayers)

 

[Tim Hall]

On Fri, 20 May 2005 17:37:29 +0100, Tony Raven <[email protected]>
wrote:

>two
>tile thicknesses short of the required length

Is that the swimmer equivalent of "two sandwiches short of a picnic"?


Tim

 

[dkahn400]

[email protected] wrote:

> What I heard was they forgot to allow for the touchpads, and it was
the
> thickness of those it was short. The disadvantages of that pool are
its two
> shallow ends, and that it is built diagonally across the building,
making
> keeping a straight course on backstroke difficult.

Would it not be possible to string tapes across the building at about
roof height for the backstrokers to follow? Or would this not help
enough?

--
Dave...

 

[Bob]

Bryan wrote:

[snipped...]

> My question on all this is, since in a previous life I used to be a
> semi decent swimmer I could never work out why one pool was
> significantly faster than another, after all water density doesn;t vary
> *that* much.

In the old days the pools were build with large side walls to contain
the water, like at Robinson poll in Bedford (where I did my first
triathlon yesterday). It makes for a choppier swim due to the waves
reflecting back into the pool, bloody nuscence.

the newer pools have the waves lapping over the edge, so less is
bounced back at the swimmer, hence they are faster to swim in.

Cheers,

--
bob [at] bobarnott [dot] com http://www.bobarnott.com/
------------------------------------------------------------------------
"Crash programs fail because they are based on theory that,
with nine women pregnant, you can get a baby in a month."
-- Wernher von Braun