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TdF and recumbents



 
 
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  #1  
Old July 27th 08, 09:23 AM posted to rec.bicycles.tech
Pat[_13_]
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Posts: 5
Default TdF and recumbents

How would a recumbent handle the Tour?
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  #2  
Old July 27th 08, 10:04 AM posted to rec.bicycles.tech
pm
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Posts: 344
Default TdF and recumbents

On Jul 27, 1:23*am, Pat wrote:
How would a recumbent handle the Tour?


Interesting choice of timing. I'd have gone earlier. Elegantly simple,
but heads for speculation straight away, without the factual veneer of
"Anyone know the last year a steel frame was used by a racing cyclist
in the TdF?" I estimate 20-40 responses.



-pm
  #3  
Old July 27th 08, 12:48 PM posted to rec.bicycles.tech,alt.rec.bicycles.recumbent
Tom Sherman[_2_]
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Posts: 9,890
Default TdF and recumbents

Pat ? wrote:
How would a recumbent handle the Tour?


Anyone that claims to provide a definitive answer is blowing smoke up
your backside, since the information does not exist to provide the
answer. You will find a lot a negative answers based on misinformation
by "experts" who have no experience or knowledge, however.

As a starting point, consider that there are only a few hundred state of
the art performance recumbent bicycles in existence (compared to tens of
thousands (or more) of state of the art upright bicycles), and most
people have never seen one unless they attend a recumbent oriented
racing series (and even there, most of the recumbents will not fit that
definition). Furthermore, of this relative handful of recumbents that
are lightweight (less than 8 kgf) and put the rider in an aerodynamic
position, only a small fraction are ridden by riders who could keep up
in a CAT 2 race on an upright, to say nothing of UCI professional level
riders. So all observations made of recumbents in the real world can
pretty much be thrown out as irrelevant to the original question.

Unless someone can demonstrate that upright riders can develop
significantly more sustained power than recumbent riders [1], there can
be little doubt that a recumbent with a seat-back 20° to 30° from the
horizontal and the pedals 20 to 25 cm higher than the seat will be
faster on the flats than a drop bar road bike or an upright TT bike.
This advantage becomes more significant in windy conditions, due to
lower wind speed within the 1 meter boundary layer between the
atmosphere and the ground. For equally talented and trained riders, the
recumbent lowracer would be faster during a flat to rolling time trial
or on a breakaway on a flat stage.

An upright sprinter can develop significantly more short term power than
a recumbent rider, based on the available information. However, as
anyone who has watched a race knows, sprinting prowess is of little
advantage, unless the sprinters are in the leading peloton near the
finish of the stage. Due to the lower frontal area of a recumbent
lowracer and the inability for an upright to effectively draft the
recumbent, the upright sprinters would not be in a position to use their
advantage in short-term power.

And of course, there are the mountain stages, where conventional wisdom
says that recumbents can not climb. The first thing is to throw out all
personal observations here, since they invariably involve recumbents
that are heavier than a state of the art CFRP lowracer and riders
considerably less able than a UCI professional.

The key is to remember that aerodynamic resistance increases with the
square of the rider's airspeed. Therefore, for average club riders, both
upright and recumbent riders will be going slowly enough that rolling
resistance and mechanical losses in the drive train will dominate, which
favors the upright. However, with a professional level rider putting out
400W on a climb, speeds become high enough that aerodynamics does
matter, even on a relatively steep climb, and an upright rider out of
the saddle is not very aerodynamic. Is the aerodynamic advantage of the
recumbent at very high rider output levels enough to compensate for the
advantages of the upright? I do not know, and more importantly, neither
does anyone else.

[1] The few studies down indicate that this is NOT the case.

--
Tom Sherman - Holstein-Friesland Bovinia
"People who had no mercy will find none." - Anon.
  #4  
Old July 27th 08, 12:49 PM posted to rec.bicycles.tech
Tom Sherman[_2_]
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Posts: 9,890
Default TdF and recumbents

pm wrote:
On Jul 27, 1:23 am, Pat wrote:
How would a recumbent handle the Tour?


Interesting choice of timing. I'd have gone earlier. Elegantly simple,
but heads for speculation straight away, without the factual veneer of
"Anyone know the last year a steel frame was used by a racing cyclist
in the TdF?" I estimate 20-40 responses.



butbutbut, this thread is not cross-posted to RBR.

--
Tom Sherman - Holstein-Friesland Bovinia
"People who had no mercy will find none." - Anon.
  #5  
Old July 27th 08, 02:28 PM posted to rec.bicycles.tech
landotter
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Posts: 6,336
Default TdF and recumbents

On Jul 27, 3:23*am, Pat wrote:
How would a recumbent handle the Tour?


It hinges critically on the square centemetres of the flippy flag that
it uses.
  #6  
Old July 27th 08, 02:42 PM posted to rec.bicycles.tech
Tom Sherman[_2_]
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Posts: 9,890
Default TdF and recumbents

landotter wrote:
On Jul 27, 3:23 am, Pat wrote:
How would a recumbent handle the Tour?


It hinges critically on the square centemetres of the flippy flag that
it uses.


I see a lot more flippy flags on uprights, especially those ridden by
suburban children on the MUPs (along with the mandatory Magic Foam
Bicycle Hat®).

--
Tom Sherman - Holstein-Friesland Bovinia
"People who had no mercy will find none." - Anon.
  #7  
Old July 27th 08, 04:52 PM posted to rec.bicycles.tech
Tim McNamara
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Posts: 6,945
Default TdF and recumbents

Pat writes:

How would a recumbent handle the Tour?


You mean, if the UCI rules permitted the use of recumbents?

They'd like have some advantage on flat breakaways and time trials,
but the disadvantages in sprinting and climbing would scupper them
compared to regular bikes.

Another factor is that recumbents are heavier than regular bikes,
although there are now some 20-22 lb recumbents (e.gg., Bacchetta)
that can be bought by Joe Everedge. That would go a long way towards
improving climbing. My friend Don's titanium Bacchetta seems to work
pretty good on climbs.
  #8  
Old July 27th 08, 05:02 PM posted to rec.bicycles.tech,alt.rec.bicycles.recumbent
[email protected][_2_]
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Posts: 1,594
Default TdF and recumbents

On Jul 27, 5:48*am, Tom Sherman
wrote:
Pat ? wrote:
How would a recumbent handle the Tour?


Anyone that claims to provide a definitive answer is blowing smoke up
your backside, since the information does not exist to provide the
answer. You will find a lot a negative answers based on misinformation
by "experts" who have no experience or knowledge, however.

As a starting point, consider that there are only a few hundred state of
the art performance recumbent bicycles in existence (compared to tens of
thousands (or more) of state of the art upright bicycles), and most
people have never seen one unless they attend a recumbent oriented
racing series (and even there, most of the recumbents will not fit that
definition). Furthermore, of this relative handful of recumbents that
are lightweight (less than 8 kgf) and put the rider in an aerodynamic
position, only a small fraction are ridden by riders who could keep up
in a CAT 2 race on an upright, to say nothing of UCI professional level
riders. So all observations made of recumbents in the real world can
pretty much be thrown out as irrelevant to the original question.

Unless someone can demonstrate that upright riders can develop
significantly more sustained power than recumbent riders [1], there can
be little doubt that a recumbent with a seat-back 20° to 30° from the
horizontal and the pedals 20 to 25 cm higher than the seat will be
faster on the flats than a drop bar road bike or an upright TT bike.
This advantage becomes more significant in windy conditions, due to
lower wind speed within the 1 meter boundary layer between the
atmosphere and the ground. For equally talented and trained riders, the
recumbent lowracer would be faster during a flat to rolling time trial
or on a breakaway on a flat stage.

An upright sprinter can develop significantly more short term power than
a recumbent rider, based on the available information. However, as
anyone who has watched a race knows, sprinting prowess is of little
advantage, unless the sprinters are in the leading peloton near the
finish of the stage. Due to the lower frontal area of a recumbent
lowracer and the inability for an upright to effectively draft the
recumbent, the upright sprinters would not be in a position to use their
advantage in short-term power.

And of course, there are the mountain stages, where conventional wisdom
says that recumbents can not climb. The first thing is to throw out all
personal observations here, since they invariably involve recumbents
that are heavier than a state of the art CFRP lowracer and riders
considerably less able than a UCI professional.

The key is to remember that aerodynamic resistance increases with the
square of the rider's airspeed. Therefore, for average club riders, both
upright and recumbent riders will be going slowly enough that rolling
resistance and mechanical losses in the drive train will dominate, which
favors the upright. However, with a professional level rider putting out
400W on a climb, speeds become high enough that aerodynamics does
matter, even on a relatively steep climb, and an upright rider out of
the saddle is not very aerodynamic. Is the aerodynamic advantage of the
recumbent at very high rider output levels enough to compensate for the
advantages of the upright? I do not know, and more importantly, neither
does anyone else.

[1] The few studies down indicate that this is NOT the case.

--
Tom Sherman - Holstein-Friesland Bovinia
"People who had no mercy will find none." - Anon.


There are a couple of guys that ride recumbents and show up to up to
our weekend rides occasionally. One of them would never be able to
keep up with our group and the other could on regular bikes. With
recumbents they keep up with the group without problems. One of them
takes pulls at 25+ mile per hour without braking a sweat. On flats,
recumbents transform average cyclists into animals. The lower the
recumbents the faster these guys become. One has a very low racing
recumbents and he built an aero contraption in the back. He goes
really fast in that apparatus and because he is very low, it is hard
to draft him. He makes a great training partner. It's sort of like
motor pacing. On hills, he slows down quite a bit though. It is not
just the weight. His racing recumbent is not that heavy.

Andres
  #9  
Old July 27th 08, 05:27 PM posted to rec.bicycles.tech
Hank
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Posts: 887
Default TdF and recumbents

On Jul 27, 8:52*am, Tim McNamara wrote:
Pat writes:
How would a recumbent handle the Tour?


You mean, if the UCI rules permitted the use of recumbents?

They'd like have some advantage on flat breakaways and time trials,
but the disadvantages in sprinting and climbing would scupper them
compared to regular bikes.

Another factor is that recumbents are heavier than regular bikes,
although there are now some 20-22 lb recumbents (e.gg., Bacchetta)
that can be bought by Joe Everedge. *That would go a long way towards
improving climbing. *My friend Don's titanium Bacchetta seems to work
pretty good on climbs.


I'm wondering how well they'd handle switchbacks, since all lowracers
are LWB, right? Plus, having the rider closer to the ground reduces
lean clearance.

I think they'd be great for TTs and probably flat road stages. In the
mountains, both climbing and descending (unless the descent is a
straightaway), not so much.

And every time Tom uses the phrase "foam hat" I want to punch him in
the neck. Not that I'm pro- or anti-helmet, it's just a jackass thing
to call it.
  #10  
Old July 27th 08, 05:39 PM posted to rec.bicycles.tech
John Forrest Tomlinson
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Posts: 6,564
Default TdF and recumbents

On Sun, 27 Jul 2008 09:23:07 +0100, Pat
wrote:

How would a recumbent handle the Tour?


Pineapples.
 




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