Numerical Benefit of Drafting

Philip W. Moore said:

Can anybody quantify the advantages of drafting in terms of reduced effort
while riding in the pack, whether in line or in an echelon? I was asked
this question by a mountain biker and could not answer it.

The answer, even if you could articulate it, would be totally irrelevant
to your mountain biking acquaintance. If he asks again, tell him the
story about teaching pigs to sing...

Alright then. Can anybody explain how this applies to roadies?

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

Quoted message said:

Philip W. Moore said:

Can anybody quantify the advantages of drafting in terms of reduced

effort

Quoted message said:

Quoted message said:

while riding in the pack, whether in line or in an echelon? I was asked
this question by a mountain biker and could not answer it.

The answer, even if you could articulate it, would be totally irrelevant
to your mountain biking acquaintance. If he asks again, tell him the
story about teaching pigs to sing...

"> Can anybody quantify the advantages of drafting in terms of reduced
effort

Quoted message said:

while riding in the pack, whether in line or in an echelon? I was asked
this question by a mountain biker and could not answer it.

Funny you should ask. Outside magazine recently published a brief article
on the effects of drafting (the recent issue with Gabrielle Reece on the
cover). According to the article, the second rider in line gets a 17%
advantage, the third rider a 38% advantage, and the fourth a 40% advantage
(assuming a race pace). Interestingly, the article claims the lead rider
gets a 3% advantage because the second rider breaks up the drag vortices
behind the lead rider.

After reading the title, I honestly thought this was going to be politically
oriented...

"Philip W. Moore, Jr." <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Can anybody quantify the advantages of drafting in terms of reduced effort
while riding in the pack, whether in line or in an echelon? I was asked
this question by a mountain biker and could not answer it.

"Philip W. Moore, Jr." <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Can anybody quantify the advantages of drafting in terms of reduced effort
while riding in the pack, whether in line or in an echelon? I was asked
this question by a mountain biker and could not answer it.

I've read some numbers before, but I think it's like the numbers I've read
about Lance's chances of surviving his cancer. One interview it was 20%,
the next it was 50%, etc.

Bob C.

Brenton,

Coming from me that might actually be a reasonable thought!

-Philip

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

Quoted message said:

After reading the title, I honestly thought this was going to be

politically

Quoted message said:

oriented...

"Philip W. Moore, Jr." <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Can anybody quantify the advantages of drafting in terms of reduced

effort

Quoted message said:

Quoted message said:

while riding in the pack, whether in line or in an echelon? I was asked
this question by a mountain biker and could not answer it.

Philip W. Moore said:

Can anybody quantify the advantages of drafting in terms of reduced effort
while riding in the pack, whether in line or in an echelon? I was asked
this question by a mountain biker and could not answer it.

I cited some research on this a couple of months ago:

http://groups.google.com/groups?selm=415a17f5%241_2%40omega.dimensional.com

--
Michael Fuhr
http://www.fuhr.org/~mfuhr/

Dumbass -

It depends upon speed, direction of the wind, etc. etc.

The faster the speed, the greater the % savings in the draft.

Riding an echelon in a crosswind gets more protection than riding on
someone's wheel right into the wind. The body (not the bike or wheels)
has the most drag and in an echelon you can get your body right next to
whomever is breaking the wind, thus the drag savings are greater.

So it varies, depending upon the situation. There is no definitive
answer.

K. Gringioni.

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

Quoted message said:

"> Can anybody quantify the advantages of drafting in terms of reduced
effort

Quoted message said:

while riding in the pack, whether in line or in an echelon? I was asked
this question by a mountain biker and could not answer it.

Funny you should ask. Outside magazine recently published a brief article
on the effects of drafting (the recent issue with Gabrielle Reece on the
cover). According to the article, the second rider in line gets a 17%
advantage, the third rider a 38% advantage, and the fourth a 40% advantage
(assuming a race pace). Interestingly, the article claims the lead rider
gets a 3% advantage because the second rider breaks up the drag vortices
behind the lead rider.

The lead rider gains 3% thing has been bounced around for a while. I
think the concensus is that it acts like the tail-cones you see on a
lot of the european tractor/trailers and eases the airflow so that it
does not create low-pressure behind the rider.

-a

"Philip W. Moore, Jr." <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Can anybody quantify the advantages of drafting in terms of reduced effort
while riding in the pack, whether in line or in an echelon? I was asked
this question by a mountain biker and could not answer it.

Pretty easy to see why it would be hard for you to describe the
sensation. Considering you are the WORLDS LARGEST FRED, and probably
can't keep up with the local bicycle touring clubs ice cream social
rides, let alone any competitive level training ride. And for the fact
that the longest you ever stayed in any draft was the first lap of the
Dallas Morning News city criterium citizen's category. And the closest
you ever got to an actual working echelon was watching WCP Spring
Classics DVD's while polishing your bike.

cp

Jr. said:

Can anybody quantify the advantages of drafting in terms of reduced effort
while riding in the pack, whether in line or in an echelon? I was asked
this question by a mountain biker and could not answer it.

None for me. No one trusted me enough to let me near their wheel.
OTOH, whenever I got close to the back of the pack, their average
speed went up by several mph.

Really kind of irritating.

Curtis L. Russell
Odenton, MD (USA)
Just someone on two wheels...

[email hidden] (crit pro) wrote in message news:<[email hidden]>...

Quoted message said:

Pretty easy to see why it would be hard for you to describe the
sensation. Considering you are the WORLDS LARGEST FRED, and probably
can't keep up with the local bicycle touring clubs ice cream social
rides, let alone any competitive level training ride. And for the fact
that the longest you ever stayed in any draft was the first lap of the
Dallas Morning News city criterium citizen's category. And the closest
you ever got to an actual working echelon was watching WCP Spring
Classics DVD's while polishing your bike.

You're a blubbering, pompous ass. You're as far removed from being a
legit pro cyclist (a.k.a. on a real Euro team) as the people rag on.
No wonder nobody in the US gives a [censored] about D3 "pros" like yourself.

Next time you go looking for the WORLD'S LARGEST FRED, try your
bathroom mirror.

Zub

Raoul Duke said:

"> Can anybody quantify the advantages of drafting in terms of reduced effort

Quoted message said:

while riding in the pack, whether in line or in an echelon? I was asked
this question by a mountain biker and could not answer it.

Quoted message said:

Funny you should ask. Outside magazine recently published a brief article
on the effects of drafting (the recent issue with Gabrielle Reece on the
cover). According to the article, the second rider in line gets a 17%
advantage, the third rider a 38% advantage, and the fourth a 40% advantage
(assuming a race pace). Interestingly, the article claims the lead rider
gets a 3% advantage because the second rider breaks up the drag vortices
behind the lead rider.

A 30% reduction in power is the number that's usually tossed around here.
I'm pretty sure that there are exercise phys studies behind this. Note
that that's 30% in power, not speed. In the middle of a 100 person
peleton, it should be larger. I don't think anyone has conclusively
demonstrated that the lead rider gets an advantage, and I'm not sure
cyclists can follow close enough to give the lead rider an advantage
(wheels keep the bodies farther apart - unlike race cars).

Like the average RBR denizen, I would probably see more than a 30% advantage
from drafting Gabrielle Reece, though.

Raoul Duke said:

"> Can anybody quantify the advantages of drafting in terms of reduced
effort

Quoted message said:

while riding in the pack, whether in line or in an echelon? I was asked
this question by a mountain biker and could not answer it.

Funny you should ask. Outside magazine recently published a brief article
on the effects of drafting (the recent issue with Gabrielle Reece on the
cover). According to the article, the second rider in line gets a 17%
advantage, the third rider a 38% advantage, and the fourth a 40% advantage
(assuming a race pace). Interestingly, the article claims the lead rider
gets a 3% advantage because the second rider breaks up the drag vortices
behind the lead rider.

It stands to reason the incremental benefit between the second and third rider is not going more than the incremental benefit between the first and second.
Whatever benefit the third rider has is going what the second rider gives him from channelling through an already reduced air-drag plus the benefit from the lead rider at a 6-8 foot distance.

At least one of those numbers is out of whack no mater what speed they are tried, or some differing conditions were present.

Critter P - - - y,

You talk a lot of [censored] for an anonymous D3 Wal-Mart parking lot racer. I
understand the basics of drafting, and was asking for more specific
information and sources.

No, I don't race bikes for a living. Because I could get into law school.
So I am sure that you know quite a bit more about bike racing than I do.

-Philip
"crit pro" <[email hidden]> wrote in message
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Quoted message said:

"Philip W. Moore, Jr." <[email hidden]> wrote in message

news:<[email hidden]>...

Quoted message said:

Quoted message said:

Can anybody quantify the advantages of drafting in terms of reduced

effort

Quoted message said:

Quoted message said:

while riding in the pack, whether in line or in an echelon? I was asked
this question by a mountain biker and could not answer it.

Pretty easy to see why it would be hard for you to describe the
sensation. Considering you are the WORLDS LARGEST FRED, and probably
can't keep up with the local bicycle touring clubs ice cream social
rides, let alone any competitive level training ride. And for the fact
that the longest you ever stayed in any draft was the first lap of the
Dallas Morning News city criterium citizen's category. And the closest
you ever got to an actual working echelon was watching WCP Spring
Classics DVD's while polishing your bike.

cp

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

Quoted message said:

Raoul Duke said:

"> Can anybody quantify the advantages of drafting in terms of reduced
effort

Quoted message said:

while riding in the pack, whether in line or in an echelon? I was

asked

Quoted message said:

this question by a mountain biker and could not answer it.

Funny you should ask. Outside magazine recently published a brief
article
on the effects of drafting (the recent issue with Gabrielle Reece on
the
cover). According to the article, the second rider in line gets a 17%
advantage, the third rider a 38% advantage, and the fourth a 40%
advantage
(assuming a race pace). Interestingly, the article claims the lead
rider
gets a 3% advantage because the second rider breaks up the drag
vortices
behind the lead rider.

It stands to reason the incremental benefit between the second and
third rider is not going more than the incremental benefit between the
first and second.
Whatever benefit the third rider has is going what the second rider
gives him from channelling through an already reduced air-drag plus the
benefit from the lead rider at a 6-8 foot distance.

At least one of those numbers is out of whack no mater what speed they
are tried, or some differing conditions were present.

It stands to reason that changing a few inputs by about 0.001% won't change
weather predictions from sunny to snowing, too. But it can. You're dealing
with a messy complicated system; common sense won't work well.

In any case, I'd imagine they simply stuck powertaps on four bikes, had them
ride in line for a while in all 24 combinations, and averaged, on a still
day on flat ground (or in a velodrome). Easy enough to set that up, and not
too error prone.

Peter

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

Quoted message said:

Raoul Duke said:

"> Can anybody quantify the advantages of drafting in terms of reduced
effort

Quoted message said:

while riding in the pack, whether in line or in an echelon? I was

asked

Quoted message said:

this question by a mountain biker and could not answer it.

Funny you should ask. Outside magazine recently published a brief
article
on the effects of drafting (the recent issue with Gabrielle Reece on
the
cover). According to the article, the second rider in line gets a 17%
advantage, the third rider a 38% advantage, and the fourth a 40%
advantage
(assuming a race pace). Interestingly, the article claims the lead
rider
gets a 3% advantage because the second rider breaks up the drag
vortices
behind the lead rider.

It stands to reason the incremental benefit between the second and
third rider is not going more than the incremental benefit between the
first and second.
Whatever benefit the third rider has is going what the second rider
gives him from channelling through an already reduced air-drag plus the
benefit from the lead rider at a 6-8 foot distance.

At least one of those numbers is out of whack no mater what speed they
are tried, or some differing conditions were present.

It stands to reason that changing a few inputs by about 0.001% won't change
weather predictions from sunny to snowing, too. But it can. You're dealing
with a messy complicated system; common sense won't work well.

In any case, I'd imagine they simply stuck powertaps on four bikes, had them
ride in line for a while in all 24 combinations, and averaged, on a still
day on flat ground (or in a velodrome). Easy enough to set that up, and not
too error prone.

Peter

meb said:

It stands to reason the incremental benefit between the second and
third rider is not going more than the incremental benefit between the
first and second.
Whatever benefit the third rider has is going what the second rider
gives him from channelling through an already reduced air-drag plus the
benefit from the lead rider at a 6-8 foot distance.

At least one of those numbers is out of whack no mater what speed they
are tried, or some differing conditions were present.

I'm pretty sure those numbers were from a peleton, and not a paceline.
I bet Outside jumbled it up.

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

Quoted message said:

A 30% reduction in power is the number that's usually tossed around here.
I'm pretty sure that there are exercise phys studies behind this.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=2318782

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10589873

And there may very well be others of which I am not aware.

Andy Coggan