Weight Weenies
* FAQ    * Search    * Trending Topics
* Login   * Register
HOME Listings Blog NEW Galleries NEW FAQ Contact About
It is currently Fri Jul 29, 2016 9:03 am
Recently the board software has been updated and there are some known bugs/failures:
- Avatars are currently not being displayed ✔ FIXED
- Tapatalk connection is currently broken ✔ FIXED
- Avatars cannot be uploaded ✔ FIXED

Please note that we will soon do some changes in WW board template design in case to get a fully mobile/desktop responsiveness board!
If you find more errors please post it here: http://weightweenies.starbike.com/forum/viewtopic.php?f=7&t=139062


All times are UTC+01:00





Post new topic  Reply to topic  [ 46 posts ]  Go to page Previous 1 2 3 4 Next
Author Message
PostPosted: Tue Feb 28, 2012 2:58 am 
Offline

Joined: Wed Dec 27, 2006 6:36 pm
Posts: 107
Valbrona wrote:
justkeepedaling wrote:
0-180? What the hell are you talking about. Are cyclists now riding in reverse?


Yaw is not the direction someone is cycling in, it is the direction of air flow. And if anyone who has ever ridden a bike knows, you can actually get wind direction in a 360 deg. fashion. Vector analysis does not translate to real life cycling very well - cycling speeds are generally quite low and variable, and wind speeds can be comparitively high. Vector analysis works with objects that move at higher speed than your average cyclist.


...maybe for YOU :roll:


Top
   
PostPosted: Tue Feb 28, 2012 3:08 am 
Offline

Joined: Mon May 30, 2005 7:13 am
Posts: 1536
Valbrona wrote:
justkeepedaling wrote:
0-180? What the hell are you talking about. Are cyclists now riding in reverse?


Yaw is not the direction someone is cycling in, it is the direction of air flow. And if anyone who has ever ridden a bike knows, you can actually get wind direction in a 360 deg. fashion. Vector analysis does not translate to real life cycling very well - cycling speeds are generally quite low and variable, and wind speeds can be comparitively high. Vector analysis works with objects that move at higher speed than your average cyclist.


What? Vectors has nothing to do with magnitude. You can calculate yaw whether you are traveling at 1mph or 100mph.

I've seen data which suggests less than 10% of all wind is over 20mph.

Anyway, play with this calendar and then talk to us about 180 degree wind:
http://www.wing-light.de/TechTalk/yaw.htm


Top
   
PostPosted: Tue Feb 28, 2012 3:10 am 
Offline

Joined: Tue Dec 27, 2011 2:19 pm
Posts: 659
Epic-o wrote:
JamieL wrote:

Image



I'm so surprised the Catlike faired so well in that test, I swear it makes my neck hurt in the crosswinds it catches so much air, but in South Texas from April-October it's totally worth it!!! :thumbup: :thumbup: :thumbup:


Top
   
PostPosted: Tue Feb 28, 2012 3:44 am 
Offline

Joined: Sat Dec 22, 2007 4:17 am
Posts: 188
Valbrona wrote:
justkeepedaling wrote:
0-180? What the hell are you talking about. Are cyclists now riding in reverse?


Yaw is not the direction someone is cycling in, it is the direction of air flow. And if anyone who has ever ridden a bike knows, you can actually get wind direction in a 360 deg. fashion. Vector analysis does not translate to real life cycling very well - cycling speeds are generally quite low and variable, and wind speeds can be comparitively high. Vector analysis works with objects that move at higher speed than your average cyclist.

Yes, wind comes from all directions, but when are you ever travelling slower than the wind? The yaw angle you care about is the direction of the air relative to the rider. Unless you aren't pedalling for some reason, that will most likely be between 0-30 deg.


Top
   
PostPosted: Tue Feb 28, 2012 6:34 am 
Offline

Joined: Thu Feb 05, 2009 12:04 am
Posts: 1117
Location: Gold Coast, QLD, Australia
bricky21 wrote:
Murphs wrote:
The Kask helmets are filled in like that, that is not a helmet cover. Sky have been using them for a number of years in the classics etc

Removable covers are illegal however.


Which model? The Sky rider behind looks to be using a standard helmet. I can't find that helmet on the Kask website, but I can't find a helmet cover either. Iirc Cav was wearing a cover in the WC road race on his specialized prevail.


Just because they're wearing one, doesn't mean you can buy one.

There was some murmur that if the UCI had actually seen Cav's helmet cover before the RR started, it would have been disallowed, but they didn't.

_________________
Bike Pure


Top
   
PostPosted: Tue Feb 28, 2012 9:18 am 
Offline

Joined: Tue Apr 12, 2011 8:08 am
Posts: 2290
Location: Pedal Square
Valbrona wrote:
justkeepedaling wrote:
0-180? What the hell are you talking about. Are cyclists now riding in reverse?


Yaw is not the direction someone is cycling in, it is the direction of air flow. And if anyone who has ever ridden a bike knows, you can actually get wind direction in a 360 deg. fashion. Vector analysis does not translate to real life cycling very well - cycling speeds are generally quite low and variable, and wind speeds can be comparitively high. Vector analysis works with objects that move at higher speed than your average cyclist.

I'm not sure how relevant the 180° yaw case is though -- anyway you would probably like to have a high drag in that case, so you catch more air and sail off the front of the group! :beerchug:

_________________
Bikes: Raw Ti, 650b flatbar CX


Top
   
PostPosted: Tue Feb 28, 2012 12:38 pm 
Offline

Joined: Tue Nov 20, 2007 7:18 pm
Posts: 608
Valbrona wrote:
Vector analysis works with objects that move at higher speed than your average cyclist.


:roll: :roll:

_________________
http://cds-0.blogspot.com


Top
   
PostPosted: Tue Feb 28, 2012 1:04 pm 
Offline
User avatar

Joined: Mon Nov 02, 2009 8:38 pm
Posts: 293
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

_________________
Blog: http://thesetbackpost.com/


Top
   
PostPosted: Tue Feb 28, 2012 2:22 pm 
Offline

Joined: Mon May 24, 2010 4:18 am
Posts: 396
Location: Australia
Have had my prevail for a year now - would not rate it very well for two reasons:
Build quality is very very ordinary compared to my met strad. Moldings are very poor with days hanging off. Stickers are peeling. Typical made in china effort cleverly disguised with a made in Macau sticker - never again!
2. Chin straps vibrate when over 30kmh. Have tried tightening as per instructions but they loosen promptly and start buzzing again.

Just my thoughts. Some love it and swear by it and I respect that.
Peace
I


Top
   
PostPosted: Wed Feb 29, 2012 8:55 pm 
Offline
User avatar

Joined: Thu May 04, 2006 4:43 pm
Posts: 5334
Location: Wherever there's a mountain beckoning to be climbed
It may not be as common as [0,30], but [90,180] yaw is possible on a bike. For example, strong predominantly tail wind up a steep climb. And yes, vector analysis applies regardless of speed, as long as you know how to apply it.


Top
   
PostPosted: Wed Feb 29, 2012 10:11 pm 
Offline

Joined: Sat Dec 17, 2011 4:38 pm
Posts: 329
Location: Netherlands
I think the closed helmets are not for aerodynamics, but to keep the wind (thus cold) out!

_________________
Pascal

2012 Colnago C59 MTBK Camapgnolo Hyperon Ultra 2 and Campi SR11
2014 Merida Big 99 CF team fully
2015 Pinarello F8 Sky Campagnolo Bora Utra 2 and Campi SR11 EPS


Top
   
PostPosted: Wed Feb 29, 2012 10:20 pm 
Offline

Joined: Wed Dec 27, 2006 6:36 pm
Posts: 107
rodebaron51 wrote:
I think the closed helmets are not for aerodynamics, but to keep the wind (thus cold) out!


They do both.


Top
   
PostPosted: Thu Mar 01, 2012 8:31 pm 
Offline

Joined: Wed Jun 10, 2009 2:16 pm
Posts: 364
Location: Austin, Texas
Vector analysis works just fine and dandy for objects as slow as cyclist - even one as slow as myself.

http://s321476941.online.de/hedgermany/ ... ulator.asp


Top
   
PostPosted: Thu Mar 01, 2012 8:40 pm 
Offline

Joined: Thu Nov 17, 2011 8:26 pm
Posts: 265
Location: Norway
Valbrona wrote:
justkeepedaling wrote:
0-180? What the hell are you talking about. Are cyclists now riding in reverse?


Yaw is not the direction someone is cycling in, it is the direction of air flow. And if anyone who has ever ridden a bike knows, you can actually get wind direction in a 360 deg. fashion. Vector analysis does not translate to real life cycling very well - cycling speeds are generally quite low and variable, and wind speeds can be comparitively high. Vector analysis works with objects that move at higher speed than your average cyclist.


What the hell are you talking about? 360 degrees almost only applies when the rider is standing still. You don't have to ride very fast before airflow relative to the rider never exceeds 20 degrees of yaw.


Top
   
PostPosted: Thu Mar 01, 2012 9:13 pm 
Offline
User avatar

Joined: Sun May 10, 2009 3:31 pm
Posts: 445
Location: Russia, Moscow
hna, 'never' is a rather strong word, isn't it? Try playing with the Apparent Wind Calculator from the link above (it's buggy in km/h, so leave it in mph) - you'll see that it's entirely possible to have sidewind of more than 20 degrees.


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

   Similar Topics   Author   Replies   Views   Last post 
There are no new unread posts for this topic. Attachment(s) rudy project aero road helmet

in Road

ophiravina

2

708

Thu May 12, 2016 9:43 am

peted76 View the latest post

There are no new unread posts for this topic. Seatpost setback and aerodynamics

[ Go to page: 1 2 ]

in Road

TomColnago

19

651

Fri Jul 22, 2016 7:44 pm

kgt View the latest post

There are no new unread posts for this topic. which helmet

[ Go to page: 1 2 ]

in Road

blondie

21

1492

Tue May 17, 2016 12:20 pm

racingcondor View the latest post

There are no new unread posts for this topic. Helmet Upgrade

[ Go to page: 1 2 ]

in Road

R350

21

1979

Sat Jul 09, 2016 7:59 pm

eaglejackson View the latest post

There are no new unread posts for this topic. Attachment(s) Abus Aero Helmet

in Road

cccycle

2

842

Sat Aug 15, 2015 10:20 am

cccycle View the latest post


All times are UTC+01:00


Who is online

Users browsing this forum: Bing [Bot], Google [Bot] and 26 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:  
Powered by phpBB® Forum Software © phpBB Limited