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the hierarchy of aero
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I would like to get thinner to the wind, and I would like the ST experts to rank the following factors from most aerodynamically impactful to least:

A rider position
B rider body shape
C bike frame
D wheels
E helmet
F shoes
G bottle between bars
H bottle on down tube
I bottle on seat tube
J bottle(s) behind saddle
K fork
L cables
M tires
N bars

(FWIW, I race on a round-tubed road bike with fastforward seatpost, tristryke saddle, old borrowed airstryke bars with profile bottle, flo 60/90 set. And I race in a road helmet with vents taped shut (race-day temps permitting). But please rank them objectively as if you were starting from scratch, not according to my particular setup. thanks.)

_____________________________________
What are you people, on dope?

—Mr. Hand
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Re: the hierarchy of aero [scofflaw] [ In reply to ]
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1.Rider position (depending on how much and what you change)
2.Aero wheels
3.Aero Helmet
4.Aero Frame/Fork

these are the most significant things the others are minor.
body shape takes a long time to change.
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Re: the hierarchy of aero [FKDUPJ] [ In reply to ]
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I would say
Rider position
Aero helmet
Wheels
Frame

My guess is rider position is 70% of the total, so more important than the others combined. Only problem is position requires wind tunnel testing, the others are generally more easy to measure, except for the "best" helmet, but an aero helmet will usually be faster than a road helmet, no matter which one you choose.
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Re: the hierarchy of aero [scofflaw] [ In reply to ]
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also depends what distance you are racing being in a aero as possible position wont make you any faster if you are not comfortable
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Re: the hierarchy of aero [scofflaw] [ In reply to ]
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Funny.....but there seems like an inverse relationship with the $ spent vs. actual benefit. Body positioning and helmets generally trump frames and wheels.
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Re: the hierarchy of aero [scofflaw] [ In reply to ]
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If you're really on a budget, I'd further break the wheels up. The front wheel is much, much more important than the rear.


Steve

"If you ain't first, you're last." Reese Bobby Talladega Nights
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Re: the hierarchy of aero [scofflaw] [ In reply to ]
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Don't forget the field of Facial Aerodynamics. There was a very detailed study done a few years back, the URL escapes me now, but I believe the picture up top represented the better findings.
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Re: the hierarchy of aero [scofflaw] [ In reply to ]
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1. position
2. tires (if you inlucde CRR)
3. the totality of not having a bunch of shit hanging off your frame
4/5: frame/wheels (tie?)
6. helmet
5. cockpit
6. fork
7. cables
8. shoes


scofflaw wrote:
I would like to get thinner to the wind, and I would like the ST experts to rank the following factors from most aerodynamically impactful to least:

A rider position
B rider body shape
C bike frame
D wheels
E helmet
F shoes
G bottle between bars
H bottle on down tube
I bottle on seat tube
J bottle(s) behind saddle
K fork
L cables
M tires
N bars

(FWIW, I race on a round-tubed road bike with fastforward seatpost, tristryke saddle, old borrowed airstryke bars with profile bottle, flo 60/90 set. And I race in a road helmet with vents taped shut (race-day temps permitting). But please rank them objectively as if you were starting from scratch, not according to my particular setup. thanks.)



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
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Re: the hierarchy of aero [scofflaw] [ In reply to ]
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http://www.socalttseries.com/...al-aerodynamics.html

Aerodynamics for Time Trial Racing - Where to invest upgrade dollars when considering new equipment and gear.
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Re: the hierarchy of aero [scofflaw] [ In reply to ]
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I haven't seen anyone mention skin suits, but some of the most dramatic improvements we've seen (other than positioning) were due to changing from shiny short-sleeved kit into long-sleeved, textured skinsuits.

"Skin is slow."
-- Paul Harder, Trek Engineer

AndyF
bike geek
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Re: the hierarchy of aero [AndyF] [ In reply to ]
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What are some brands/models that are pretty legit that you have seen?

I just have a basic champsys. If I went fancy would I break the sound barrier?

AndyF wrote:
I haven't seen anyone mention skin suits, but some of the most dramatic improvements we've seen (other than positioning) were due to changing from shiny short-sleeved kit into long-sleeved, textured skinsuits.

"Skin is slow."
-- Paul Harder, Trek Engineer



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
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Re: the hierarchy of aero [jackmott] [ In reply to ]
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the basic champsys was slower for me than the team run of the mill suit.

the thought was the texture all the way along the flat torso/back was texture in the wrong place
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Re: the hierarchy of aero [jackmott] [ In reply to ]
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jackmott wrote:
What are some brands/models that are pretty legit that you have seen?

I've personally seen good improvements with one of the newer Champ-Sys cycling speed suits, although I'm not sure if it's out yet. And the Pearl-Izumi Octane trisuit tested pretty well, too.

For a more complete list I'll defer to Jim Manton, who has probably seen a lot more tests.

AndyF
bike geek
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Re: the hierarchy of aero [nickag] [ In reply to ]
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Only problem is position requires wind tunnel testing

Not.

Though it is hard to do accurately without a PM. But even then you can look at frontal area and smart practices.



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Re: the hierarchy of aero [AndyF] [ In reply to ]
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"Skin is slow."
-- Paul Harder, Trek Engineer

Hairy skin is probably worse...

I have a textured Voler suit... but it doesn't seem to be any lower drag than my old and smooth ones. I'd happily spend $300 on a new suit if I thought it would reduce my CdA by 5% or better.

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Re: the hierarchy of aero [scofflaw] [ In reply to ]
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  1. Position
  2. Clothing
  3. Helmet or Wheels
  4. Helmet or Wheels
  5. Clean front end (i.e.cables)
  6. Proper hydration setup
  7. Frame
Castelli Body Paint II seems to be very consistently fast. Champion Systems is coming out with a VERY good skin suit. For tri, you're giving up minutes if you're not using a Pearl Izumi Tri Octane. Seriously, that suit is amazing.

Jim Manton / ERO Sports
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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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Jim@EROsports wrote:
  1. Position
  2. Clothing
  3. Helmet or Wheels
  4. Helmet or Wheels
  5. Clean front end (i.e.cables)
  6. Proper hydration setup
  7. Frame
Castelli Body Paint II seems to be very consistently fast. Champion Systems is coming out with a VERY good skin suit. For tri, you're giving up minutes if you're not using a Pearl Izumi Tri Octane. Seriously, that suit is amazing.

Always listen to the best bike fitter on the planet! Jim set me up in a perfect tt position, one I've been able to ride in for rides as long as 138 miles with very minimal time out of the extensions.

Now I need to work on the motor...
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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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Can you point out key differences between the Pearl Tri Octane suit and a skin suit? It looks like they are close to one in the same.

24 Hour World TT Champs-American record holder
Fat Bike Worlds - Race Director
Insta: chris.s.apex
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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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Jim@EROsports wrote:
Castelli Body Paint II seems to be very consistently fast. Champion Systems is coming out with a VERY good skin suit. For tri, you're giving up minutes if you're not using a Pearl Izumi Tri Octane. Seriously, that suit is amazing.

Have you tested the LG Course TT skinsuit?
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Re: the hierarchy of aero [Tri Slow Poke] [ In reply to ]
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Tri Slow Poke wrote:
Funny.....but there seems like an inverse relationship with the $ spent vs. actual benefit. Body positioning and helmets generally trump frames and wheels.

Maybe... better positioning isn't necessarily free, depending on where you start and what sort of equipment choices may facilitate positioning improvements. It *could* be as simple as moving your saddle forward and/or flipping the stem/spacers; or, it could lead to new saddle, bars/stem, even a new frame, etc. I was kind of at the limit of where I could get with my old converted road frame & bent forward seatpost, for example, so buying a TT/Tri-specific frame accomplished both position gains as well as reduced drag of the frame itself.
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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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Jim@EROsports wrote:
For tri, you're giving up minutes if you're not using a Pearl Izumi Tri Octane. Seriously, that suit is amazing.
Minutes? For what distance?



http://www.frostyjunction.com/
https://twitter.com/FrostyJunction
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Re: the hierarchy of aero [scofflaw] [ In reply to ]
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One thing you might do -- particularly for those on a budget -- is separate front and rear wheel. As I understand it, a front aero wheel gives you a much bigger improvement than a rear.
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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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Jim@EROsports wrote:
  1. Position
  2. Clothing
  3. Helmet or Wheels
  4. Helmet or Wheels
  5. Clean front end (i.e.cables)
  6. Proper hydration setup
  7. Frame
Castelli Body Paint II seems to be very consistently fast. Champion Systems is coming out with a VERY good skin suit. For tri, you're giving up minutes if you're not using a Pearl Izumi Tri Octane. Seriously, that suit is amazing.
Jim has more experience testing than everyone else here combined, so you have your answer.

I would add that number 1 is by far the most important. I can get 80% of the entire benefit from just position (as long as clothing is decent tight fitting cycling uniform type stuff). So if you want to save money just do lots of aero testing and refine your position. Once there buy a good skin suit and helmet and, to be honest, you've got most of what you're going to get right there.
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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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Castelli Body Paint II seems to be very consistently fast.

Thanks Jim! Can you give an idea of the drag reduction compared to...?

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Re: the hierarchy of aero [FrostyJ] [ In reply to ]
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FrostyJ wrote:
Jim@EROsports wrote:
For tri, you're giving up minutes if you're not using a Pearl Izumi Tri Octane. Seriously, that suit is amazing.
Minutes? For what distance?

And also always curious as compared to what? Like is it minutes over cargo shorts and and a hoodie or minutes over the last skin suit?

Not saying the info isn't valid but that often seems to be glanced over.

Like the link above to some TT testing saying that there was something like 2-4 minutes to be found with aero wheels over 32 spoke box rim wheels, but really how many people are jumping from that to aero wheels and not something that is 20-24 spokes and already slightly aero? Heck the 10 year old (ok I replaced the rear) wheels I use off my trek 1500 weren't 32 spoke box wheels.

It's kind of like if Ford said the new GT500 makes 4X the power of the old mustang.. but they didn't mean the 12' GT500 they meant a base 4 cylinder fox body.


Again not saying someone is misrepresenting things just sometimes it is hard to decipher if the new shiny takes minutes off last weeks now old shiny or the 10 year old never was shiny.
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