Need those brains again

"Bob" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

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.

Quoted message said:

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

Apparently, height above sea-level.

Tom.

Bob said:

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

Bryan said:

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

Bryan said:

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.

Bryan said:

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)

Quoted message said:

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

Quoted message said:

*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.

We're getting off the track here brains!

Bob said:

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

In article said:

Quoted message said:

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

Quoted message said:

*that* much.

(With the exception of salt water pools.)

Quoted message said:

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.

Quoted message said:

So if a cross-wind has no or little effect on forward motion

But it does - try a little observational science... :-)

Quoted message said:

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...

Quoted message said:

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

*All* the other variables.

Graham

"Bob" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

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.

sean said:

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?

sean said:

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)

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

Quoted message said:

two
tile thicknesses short of the required length

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

Tim

Quoted message said:

What I heard was they forgot to allow for the touchpads, and it was

the

Quoted message said:

thickness of those it was short. The disadvantages of that pool are

its two

Quoted message said:

shallow ends, and that it is built diagonally across the building,

making

Quoted message said:

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...

Bryan wrote:

[snipped...]

Quoted message said:

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."
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