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  #1  
Old January 28th 08, 11:29 PM posted to rec.bicycles.racing
Scott
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Posts: 1,859
Default And if you believe that

I've got a bridge to sell you.

OK, time to call BS.

Articles on the 2nd stage of the Tour of Qatar discuss an average
speed of 35+ MPH for the first hour (not terribly unbelievable), and
later in the race a 5km or so section where Quickstep reportedly
ramped the speed up to 43+ MPH... in CROSSWINDS.

Right.
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  #2  
Old January 29th 08, 01:06 AM posted to rec.bicycles.racing
[email protected]
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Posts: 769
Default And if you believe that

On Jan 28, 6:29*pm, Scott wrote:
I've got a bridge to sell you.

OK, time to call BS.

Articles on the 2nd stage of the Tour of Qatar discuss an average
speed of 35+ MPH for the first hour (not terribly unbelievable), and
later in the race a 5km or so section where Quickstep reportedly
ramped the speed up to 43+ MPH... in CROSSWINDS.

Right.


easier to believe they interchanged mph for kph without converting
  #4  
Old January 29th 08, 03:27 PM posted to rec.bicycles.racing
Scott
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Posts: 1,859
Default And if you believe that

On Jan 28, 6:43*pm, Keith wrote:
On Mon, 28 Jan 2008 17:06:59 -0800 (PST), wrote:
On Jan 28, 6:29*pm, Scott wrote:
I've got a bridge to sell you.


OK, time to call BS.


Articles on the 2nd stage of the Tour of Qatar discuss an average
speed of 35+ MPH for the first hour (not terribly unbelievable), and
later in the race a 5km or so section where Quickstep reportedly
ramped the speed up to 43+ MPH... in CROSSWINDS.


Right.


easier to believe they interchanged mph for kph without converting


+1 , OP is an idiot or a troublemaker


Excuse me, but how exactly does pointing out the absurdity in a claim
of 43+ mph for over 5k at the end of a 150+ km stage fighting through
crosswinds make me either an idiot or a troublemaker?

If they were going downhill (which apparently they don't have in
Qatar), maybe. If they had screaming tailwinds, yes. But, if they
were doing 43+ in a tailwind, it wouldn't have blown the field apart.

If you think the reported speeds were accurate, consider this.
Assuming they were running a top gear of 53x11, they would have to do
over 115 rpm in that gear to even reach that speed. The power output
required to do that is something that only top sprinters can even do,
and no one maintains it for the time required to travel more than 3 or
4 hundred meters, not 5 thousand meters.

Unless, of course, they're all doping. Wait, that's it. No wonder
all but two of the Slipstream riders were over 8 minutes back.
  #5  
Old January 29th 08, 04:11 PM posted to rec.bicycles.racing
TJG
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Posts: 19
Default And if you believe that

On Jan 28, 8:43 pm, Keith wrote:
On Mon, 28 Jan 2008 17:06:59 -0800 (PST), wrote:
On Jan 28, 6:29 pm, Scott wrote:
I've got a bridge to sell you.


OK, time to call BS.


Articles on the 2nd stage of the Tour of Qatar discuss an average
speed of 35+ MPH for the first hour (not terribly unbelievable), and
later in the race a 5km or so section where Quickstep reportedly
ramped the speed up to 43+ MPH... in CROSSWINDS.


Right.


easier to believe they interchanged mph for kph without converting


+1 , OP is an idiot or a troublemaker


Well maybe. But I rather believe that it was correctly reported.
CyclingNews.com said the push came leading up to the 2nd sprint bonus.
That was on the road to Al Khor. If the wind was blowing from the
west, it would have been at their backs on that stretch.
  #6  
Old January 29th 08, 04:16 PM posted to rec.bicycles.racing
TJG
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Posts: 19
Default And if you believe that

On Jan 29, 10:27 am, Scott wrote:
On Jan 28, 6:43 pm, Keith wrote:



On Mon, 28 Jan 2008 17:06:59 -0800 (PST), wrote:
On Jan 28, 6:29 pm, Scott wrote:
I've got a bridge to sell you.


OK, time to call BS.


Articles on the 2nd stage of the Tour of Qatar discuss an average
speed of 35+ MPH for the first hour (not terribly unbelievable), and
later in the race a 5km or so section where Quickstep reportedly
ramped the speed up to 43+ MPH... in CROSSWINDS.


Right.


easier to believe they interchanged mph for kph without converting


+1 , OP is an idiot or a troublemaker


Excuse me, but how exactly does pointing out the absurdity in a claim
of 43+ mph for over 5k at the end of a 150+ km stage fighting through
crosswinds make me either an idiot or a troublemaker?

If they were going downhill (which apparently they don't have in
Qatar), maybe. If they had screaming tailwinds, yes. But, if they
were doing 43+ in a tailwind, it wouldn't have blown the field apart.

If you think the reported speeds were accurate, consider this.
Assuming they were running a top gear of 53x11, they would have to do
over 115 rpm in that gear to even reach that speed. The power output
required to do that is something that only top sprinters can even do,
and no one maintains it for the time required to travel more than 3 or
4 hundred meters, not 5 thousand meters.

Unless, of course, they're all doping. Wait, that's it. No wonder
all but two of the Slipstream riders were over 8 minutes back.


It blew it apart because they were going at a blistering pace form the
get-go. The ones off the back were at their limit already and said so.
Only the ones with enough in reserve could take avantage of the
tailwind. Strategy.
  #7  
Old January 29th 08, 11:14 PM posted to rec.bicycles.racing
John Forrest Tomlinson
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Posts: 6,564
Default And if you believe that

On Tue, 29 Jan 2008 07:27:09 -0800 (PST), Scott
wrote:

If they had screaming tailwinds, yes. But, if they
were doing 43+ in a tailwind, it wouldn't have blown the field apart.


Racing in strong tailswinds are brutal - much more condusive to fields
exploding than still air or headwinds

  #8  
Old January 29th 08, 11:33 PM posted to rec.bicycles.racing
Scott
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Posts: 1,859
Default And if you believe that

On Jan 29, 4:14*pm, John Forrest Tomlinson
wrote:
On Tue, 29 Jan 2008 07:27:09 -0800 (PST), Scott

wrote:
If they had screaming tailwinds, yes. *But, if they
were doing 43+ in a tailwind, it wouldn't have blown the field apart.


Racing in strong tailswinds are brutal - much more condusive to fields
exploding than still air or headwinds


Why do you conclude that?
  #9  
Old January 30th 08, 12:01 AM posted to rec.bicycles.racing
John Forrest Tomlinson
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Posts: 6,564
Default And if you believe that

On Tue, 29 Jan 2008 15:33:25 -0800 (PST), Scott
wrote:

On Jan 29, 4:14*pm, John Forrest Tomlinson
wrote:
On Tue, 29 Jan 2008 07:27:09 -0800 (PST), Scott

wrote:
If they had screaming tailwinds, yes. *But, if they
were doing 43+ in a tailwind, it wouldn't have blown the field apart.


Racing in strong tailswinds are brutal - much more condusive to fields
exploding than still air or headwinds


Why do you conclude that?


Experience.

  #10  
Old January 30th 08, 01:04 AM posted to rec.bicycles.racing
Ryan Cousineau
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Posts: 2,383
Default And if you believe that

In article
,
Scott wrote:

On Jan 29, 4:14*pm, John Forrest Tomlinson
wrote:
On Tue, 29 Jan 2008 07:27:09 -0800 (PST), Scott

wrote:
If they had screaming tailwinds, yes. *But, if they
were doing 43+ in a tailwind, it wouldn't have blown the field apart.


Racing in strong tailswinds are brutal - much more condusive to fields
exploding than still air or headwinds


Why do you conclude that?


Either because he's done it, or because he has a brain. Since it's JT, I
suspect the right answer is both.

Tailwinds reduce the advantage of a peloton versus a solo rider, and
confound the peloton in subtler ways. The lead riders are effectively
"sheltered" from the benefits of the tailwind, thus making the relative
efforts of the lead rider and the pack even more disparate than usual.
The effect is that a rider who jumps off the front of the pack can do so
with less effort than usual, while the rider who stays at the lead of
the pack has to put out more (relative) effort than usual.

There's also some daffy bunching-up effects, since the guys at the very
back of the pack are doing even less work than usual, and getting popped
off the back of the pack is slightly less consequential than usual, and
less likely since the ramp-up in drag is less than usual.

It may be easier to understand by examining the effect of a headwind:
the higher wind-speed means that the draft is more effective
(paceline/peloton drafting advantage rises rapidly with increasing
cyclist speeds, and a headwind effectively increases the "airspeed," to
borrow a flying term). The peloton compensates with shorter pulls at the
front (or, alternatively, the lead riders are just burning more matches;
either way, spending time in the lead is especially costly), and the
cost of trying an escape is higher, because the power-increase required
to solo off is greater.

I punched in some numbers into this (admittedly crude) calculator:

http://www.exploratorium.edu/cycling/aerodynamics1.html

Start with a 150 pound cyclist (obviously a rouleur type) and 0 slope.

25 mph, 0 wind, 184 Watts required
27 mph, 0 wind, 258 Watts required.

Now, some wind:

24 mph, 10 mph wind, 462 Watts required. Wow.
26 mph, 10 mph wind, 548 Watts required.

And of course, you probably can still get to 24 mph in a heavy headwind,
because the guys at the front take short (hard) pulls, and rest in the
pack, where the draft largely shelters you from the headwind. In other
words, your at-the-front efforts are very high, but you still have
nearly the same (minimal) power needs while you're resting in the draft.
So the pack doesn't slow down a lot, but more people contribute to the
work, or you might get a little less rest, but it feels great.

Humans are good at sprint-rest cycles like this. Lots of pro riders can
do 1-minute 500-Watt efforts every ten minutes for hours at a time. But
Willett notes that 376 Watts for an hour is good enough for a gold-medal
Olympic TT.

Compare to a solo attacker in a headwind, who must take on a
all of the burden of this sprint-level effort, and doesn't get to rest.
In other words, they're doing that solo TT. So let's go straight out and
assume that they're putting out 376 Watts. In a 10 mph headwind, that
equates to a solo speed of about 21-22 mph.

Any guesses as to how good a 10-man paceline would have to be to
maintain 23 mph (~37 km/h) in a 10 mph headwind? I don't have a
calculator for it, but this sounds like a Cat 3 effort. And they could
catch David Millar trying to solo away from them.

Okay, so the Cat 3's are clearly doping, (cf Millar Line), and even
TT-specialist Millar probably has enough sprint (or at least 10-minute
power) to take the victory, but a serious solo effort will never work in
these conditions.

So that's for a head wind. A tail wind has roughly the opposite effect.

--
Ryan Cousineau http://www.wiredcola.com/
"My scenarios may give the impression I could be an excellent crook.
Not true - I am a talented lawyer." - Sandy in rec.bicycles.racing
 




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