Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Track Cycling: Velodrome Racing and Training Area Looking to enter into the realm of track racing? Want to share your experiences and tactics for riding on a velodrome? The Track Cycling forums is for you! Come in and discuss training/racing, equipment, and current track cycling events.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 05-14-12, 10:25 AM   #1
joshpants
Senior Member
Thread Starter
 
joshpants's Avatar
 
Join Date: Aug 2011
Location: Golden, CO
Bikes:
Posts: 79
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Anyone for physics? (article on banking...)

http://www.theaftermatter.com/2012/0...elodromes.html

Enjoy.

-josh
joshpants is offline   Reply With Quote
Old 05-14-12, 10:58 AM   #2
carleton
Elitist
 
carleton's Avatar
 
Join Date: Jul 2005
Location: Atlanta, GA
Bikes:
Posts: 13,135
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 43 Post(s)
Quote:
This means that a cyclist can only go at about 45.5 km/h around a [flat] corner without losing grip
I always wondered about that.
__________________
Quote:
Originally Posted by gtrob View Post
Roadies can run tempo all year as that's what humans were designed for. If you want to be a cheetah, lay around and lick your paws more.
carleton is offline   Reply With Quote
Old 05-14-12, 01:08 PM   #3
Speedskater
Senior Member
 
Speedskater's Avatar
 
Join Date: Jun 2007
Location: Cleveland
Bikes: Bob Jackson, Trek & Sampson
Posts: 259
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
That calculation only works when:

The radius of a turn on a Olympic velodrome is around 20 meters,

Now Short Track Ice Speedskaters with lots more traction on flat ice can corner way faster!
Speedskater is offline   Reply With Quote
Old 05-14-12, 04:33 PM   #4
bitingduck
Senior Member
 
bitingduck's Avatar
 
Join Date: Jan 2005
Bikes:
Posts: 3,057
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Speedskater View Post
That calculation only works when:

The radius of a turn on a Olympic velodrome is around 20 meters,

Now Short Track Ice Speedskaters with lots more traction on flat ice can corner way faster!
Speedskates have long sharp edges that dig into the ice in one axis and slide nicely across it on the other.

The article leaves out a lot of interesting physics about why the turns generally aren't semicircles, as well as some interesting angular momentum effects.
__________________
Track - the other off-road
http://www.lavelodrome.org
bitingduck is offline   Reply With Quote
Old 05-15-12, 11:07 AM   #5
chas58
Senior Member
 
chas58's Avatar
 
Join Date: Jul 2010
Location: Michigan
Bikes: too many of all kinds
Posts: 1,632
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Quote:
Originally Posted by bitingduck View Post
The article leaves out a lot of interesting physics about why the turns generally aren't semicircles, as well as some interesting angular momentum effects.
So, what are the other interesting bits of physics, and why are velodrome turns not a constant radius?
chas58 is offline   Reply With Quote
Old 05-16-12, 10:43 AM   #6
Dolamite02
Senior Member
 
Dolamite02's Avatar
 
Join Date: Sep 2009
Location: Houston, TX
Bikes: Bianchi Pista, Bianchi via Nirone 7, GT Zaskar 9r Sport
Posts: 960
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by carleton View Post
I always wondered about that.
Note too, that this is only on a wood surface, not concrete.
Dolamite02 is offline   Reply With Quote
Old 05-16-12, 11:21 AM   #7
bitingduck
Senior Member
 
bitingduck's Avatar
 
Join Date: Jan 2005
Bikes:
Posts: 3,057
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by chas58 View Post
So, what are the other interesting bits of physics, and why are velodrome turns not a constant radius?
If you go from the straightaway into a constant radius turn you go instantly from no centripetal acceleration to V^2/R, and it would be instant changes from no "compression" to max compression and then suddenly back. Instead they're a cycloid (or close to it) so the centripetal acceleration comes on slow, hits a max at the middle of the turn, and decreases slowly as you exit.

Another thing that's fun is conservation of angular momentum-- it helps in the paceline transitions in the corners (in addition to the elevation change effects).
__________________
Track - the other off-road
http://www.lavelodrome.org
bitingduck is offline   Reply With Quote
Old 06-11-12, 07:32 PM   #8
San Rensho 
Senior Member
 
Join Date: Oct 2005
Bikes:
Posts: 5,547
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Quote:
Originally Posted by carleton View Post
I always wondered about that.
But you are going to strike a pedal way before 45 kph.
__________________
Il faut de l'audace, encore de l'audace, toujours de l'audace

1980 3Rensho-- 1975 Raleigh Sprite 3spd
1990s Raleigh M20 MTB--2007 Windsor Hour (track)
1988 Ducati 750 F1
San Rensho is offline   Reply With Quote
Old 07-04-12, 09:19 AM   #9
KrautFed
cars are fun
 
Join Date: Jul 2006
Location: Baton Rouge, LA
Bikes:
Posts: 235
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It is a good start to the basics. The coefficient of friction is a variable on a bicycle. The author's first equation assumes that turning a bicycle is flat. Turning a bicycle on flat ground requires a lean which changes force vectors and friction. He/She doesn't come back to this until the end of the article where a correction is added.

I think there should have been material on the basics of superelevation.
KrautFed is offline   Reply With Quote
Old 07-04-12, 09:28 AM   #10
taras0000
Senior Member
 
taras0000's Avatar
 
Join Date: Dec 2004
Location: Edmonton, AB
Bikes:
Posts: 849
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Quote:
Originally Posted by bitingduck View Post
If you go from the straightaway into a constant radius turn you go instantly from no centripetal acceleration to V^2/R, and it would be instant changes from no "compression" to max compression and then suddenly back. Instead they're a cycloid (or close to it) so the centripetal acceleration comes on slow, hits a max at the middle of the turn, and decreases slowly as you exit.

Another thing that's fun is conservation of angular momentum-- it helps in the paceline transitions in the corners (in addition to the elevation change effects).
Is it a cycloid? I always thought it was some form of Euler curve. I've never thought if a cycloid in being used for a banking. They both make sense to me in some respects, but not being a rocket surgeon, I wouldn't know which is best.
taras0000 is offline   Reply With Quote
Old 07-04-12, 11:45 AM   #11
taras0000
Senior Member
 
taras0000's Avatar
 
Join Date: Dec 2004
Location: Edmonton, AB
Bikes:
Posts: 849
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Also found this if anyone is interested

http://en.wikipedia.org/wiki/Track_transition_curve
taras0000 is offline   Reply With Quote
Old 07-04-12, 07:06 PM   #12
David Broon 
Sqrl
 
Join Date: Mar 2012
Bikes:
Posts: 553
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I'm a simplistic kind of guy. The kind who rides bikes in a circle. Fast.



Somebody want to explain to us ordinary mortals what's going on?
__________________
Quote:
Originally Posted by carleton View Post
Doing one-legged squats while holding chickens in each hand will make someone strong...that doesn't mean it's the best way to train for track racing.
Quote:
Originally Posted by Nagrom_ View Post
That would be spectacular. A trail of blood and sealant.
David Broon is offline   Reply With Quote
Old 07-05-12, 04:44 PM   #13
KrautFed
cars are fun
 
Join Date: Jul 2006
Location: Baton Rouge, LA
Bikes:
Posts: 235
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by David Broon View Post
I'm a simplistic kind of guy. The kind who rides bikes in a circle. Fast.



Somebody want to explain to us ordinary mortals what's going on?
To turn fast, you must lean. To go (X) amount of speed, you must lean (C) amount of degrees. (C) amount of degrees is already farther than a bike can lean (A). So to get to the (C) degree angle needed, the track must me leaned as well (B). Therefore (A)+(B) = (C) and we can turn while going (X) amount of speed.
KrautFed is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 03:13 AM.