HOT: Active* forum members generally gain 5% discount at starbike.com store!
Weight Weenies
* FAQ    * Search    * Trending Topics
* Login   * Register
HOME Listings Articles FAQ Contact About




Post new topic Reply to topic  [ 46 posts ] 
Go to page Previous  1, 2, 3, 4  Next
Author Message
PostPosted: Thu Mar 01, 2012 9:28 pm 
Offline
User avatar

Joined: Thu May 04, 2006 4:43 pm
Posts: 5068
Location: Wherever there's a mountain beckoning to be climbed
As I stated above, strong predominantly tail wind up a steep climb can put you at or near 180. There is continuum of possibilities from 180 all the way to zero.


Top
 Profile  
 
 Post subject: Road Helmet Aerodynamics
PostPosted: Thu Mar 01, 2012 9:31 pm 
Offline

Joined: Wed Jun 10, 2009 2:16 pm
Posts: 348
Location: Austin, Texas
180 degree angle of 'attack' is possible, but you have to stop and use some common sense to how that applies to aero design. If I'm riding 15 mph with a 30 mph tailwind, that is indeed a 15 mph 'wind' at 180 degrees.

But you would never want to consider such a silly scenario in a testing protocol, let alone try to consider in an aero design. Such extreme design conditions won't lend to a faster product and can thus be ignored.


Top
 Profile  
 
 Post subject: Road Helmet Aerodynamics
Posted: Thu Mar 01, 2012 9:31 pm 


Top
  
 
PostPosted: Thu Mar 01, 2012 10:00 pm 
Offline

Joined: Thu Jan 03, 2008 6:14 am
Posts: 1136
Location: by Crystal Springs (Sawyer Creek Trail)
Not only that, but you'd want the frontal area as high as possible. If the actual yaw really is 180 degrees, aero doesn't matter. You're going slow enough that weight would matter more with climbing, or you'd actually want the opposite of typical aero concepts. Just sit up onto the tops and get pushed along. Has NOTHING to do with low drag aerodynamics. In fact, it's such a small percentage of occurance that it can be considered negligible.


Top
 Profile  
 
PostPosted: Thu Mar 01, 2012 10:20 pm 
Offline
User avatar

Joined: Thu May 04, 2006 4:43 pm
Posts: 5068
Location: Wherever there's a mountain beckoning to be climbed
People, I was correcting technically erroneous statements made on this thread. I was not stating the optimal way of optimizing for aero.


Top
 Profile  
 
PostPosted: Fri Mar 02, 2012 1:47 am 
Offline

Joined: Thu Jan 03, 2008 6:14 am
Posts: 1136
Location: by Crystal Springs (Sawyer Creek Trail)
Well, obviously most comments are trying to refer to optimized aerodynamics. Stuff that makes you faster rather than pretty much negligible technicalities that have complete opposite results.


Top
 Profile  
 
PostPosted: Sat Mar 03, 2012 10:37 pm 
Offline

Joined: Thu May 25, 2006 8:20 am
Posts: 243
Location: Zolder, Belgium.
MajorMantra wrote:
Roeboe wrote:
I think the main reason is for keeping the head wind and water free, since you lose most energy (heat) trough your head.


Myth!:

http://www.guardian.co.uk/science/2008/ ... nbehaviour" onclick="window.open(this.href);return false;


Well, if you leave you head uncovered, it is the only exposed body part so you will lose more heat there.


Top
 Profile  
 
PostPosted: Sat Mar 03, 2012 10:54 pm 
Offline
User avatar

Joined: Mon Nov 02, 2009 8:38 pm
Posts: 291
Roeboe wrote:
MajorMantra wrote:
Roeboe wrote:
I think the main reason is for keeping the head wind and water free, since you lose most energy (heat) trough your head.


Myth!:

http://www.guardian.co.uk/science/2008/ ... nbehaviour" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;


Well, if you leave you head uncovered, it is the only exposed body part so you will lose more heat there.


Exactly. But it is often stated that you lose a disproportionate amount of heat through your head which never been shown to be the case.

_________________
Blog: http://thesetbackpost.com/


Top
 Profile  
 
PostPosted: Sun Mar 04, 2012 2:39 am 
Offline

Joined: Fri Oct 28, 2011 3:25 am
Posts: 750
Location: United Kingdom of Great Britain and Northern Ireland
Epic-o wrote:
Image


The Dandy only wore this helmet because it was more fashionable.

And lets not forget that most road racing is done in the slipstream/dirty air of the guys in front. There is no smooth air flow like you might get in a wind tunnel.


Top
 Profile  
 
PostPosted: Sun Mar 04, 2012 5:01 am 
Offline

Joined: Mon May 30, 2005 7:13 am
Posts: 1510
Valbrona, how can you continue to post about aerodynamics when we completely discredited your ideas about 360 degrees of yaw?


Top
 Profile  
 
PostPosted: Sun Mar 04, 2012 5:18 am 
Offline

Joined: Thu Jan 03, 2008 6:14 am
Posts: 1136
Location: by Crystal Springs (Sawyer Creek Trail)
Oh, I see! Breakaways never succeed and sprints end in a single file line every time!


Top
 Profile  
 
PostPosted: Sun Mar 04, 2012 5:50 am 
Offline

Joined: Thu Feb 09, 2012 2:55 am
Posts: 16
I want one that pops open a properly positioned sail when it senses a tailwind of any "yaw." Would that be legal?


Top
 Profile  
 
PostPosted: Sun Mar 04, 2012 7:16 am 
Offline

Joined: Tue Oct 14, 2008 7:39 am
Posts: 367
Location: Melbourne
The Bontrager claim the Oracle wind tunnel tests show it beats the comp, especially at angles of yaw.

Enticing, especially as the Previal test data was only at 0 deg, but what is "the comp"?

It has been said before but it never ceases to amaze that this isn't an area of focus or battle - spend $3K+ on a slightly new wheel shape but not worry about the drag on that massive blob that hits the wind...if I were making road helmets I would develop it in the tunnel and make a massive fuss about it.


Top
 Profile  
 
PostPosted: Sun Mar 04, 2012 5:40 pm 
Offline
User avatar

Joined: Mon Nov 02, 2009 8:38 pm
Posts: 291
SQ wrote:
It has been said before but it never ceases to amaze that this isn't an area of focus or battle - spend $3K+ on a slightly new wheel shape but not worry about the drag on that massive blob that hits the wind.


Maybe it's because, up until now at least, aero helmets have been really dorky whereas aero wheels look sweet. :)

_________________
Blog: http://thesetbackpost.com/


Top
 Profile  
 
PostPosted: Wed Apr 18, 2012 7:28 pm 
Offline
Formerly known as wassertreter

Joined: Tue Apr 12, 2011 8:08 am
Posts: 1855
Location: Pedal Square
Does anyone know which Helmet Rodriguez wore when winning La Fleche? It almost looked like a TT hemet from the side, with the prolonged tail. Is this the Radius model?

_________________
Bikes: Raw Ti, 650b flatbar CX


Top
 Profile  
 
PostPosted: Thu Apr 19, 2012 1:48 pm 
Offline

Joined: Thu Feb 03, 2011 2:28 pm
Posts: 371
I'm also interested in the OP's question. I'm looking for a helmet for a very long, and hence very slow speed, TT i.e. one that will be most aero through a wide range of relatively high yaw angles.

I was thinking that something like the Giro that Miller wore in the final stage of the Tour last year (I don't care about being thought a "dandy") or the Kasks that Sky use would be ideal.
Image

I've not found any news about what happened to the Giro proto, and the Kasks won't be available until after the Olympics due to an exclusivity deal with Team GB (http://forum.slowtwitch.com/gforum.cgi?post=3455724).

The closest I can find is the Casco Warp track helmet:
Image

Does anyone have any other ideas?


Top
 Profile  
 
Posted: Thu Apr 19, 2012 1:48 pm 


Top
  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 46 posts ] 
Go to page Previous  1, 2, 3, 4  Next


Who is online

Users browsing this forum: Exabot [Bot], Google [Bot], Google Adsense [Bot], MSN [Bot] and 59 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

   Similar Topics   Author   Replies   Views   Last post 
There are no new unread posts for this topic. NEW KASK Road Helmet at TdF

in Road

passione

13

2047

Wed Jul 16, 2014 5:41 pm

djconnel View the latest post

There are no new unread posts for this topic. Road or MTB helmet version : any differences ?

in Road

LouisN

3

350

Fri Feb 07, 2014 3:53 pm

project3 View the latest post

There are no new unread posts for this topic. Aero road helmet comparison test

in Road

jaketim114

2

1529

Mon Sep 09, 2013 3:23 am

prendrefeu View the latest post

There are no new unread posts for this topic. Best Ventilated Helmet

[ Go to page: 1, 2 ]

in Road

Rick

22

1655

Wed Jun 18, 2014 8:37 am

micky View the latest post

There are no new unread posts for this topic. painting helmet?

in Road

Zak

4

524

Wed May 07, 2014 9:25 pm

mile2424 View the latest post


It is currently Fri Aug 01, 2014 9:50 am

All times are UTC + 1 hour




Advertising   –  FAQ   –  Contact   –  Convert   –  About

© Weight Weenies 2000-2013
hosted by starbike.com


How to get rid of these ads? Just register!


Powered by phpBB