myiW Current Conditions and Forecasts Community Forums Buy and Sell Services
 
Hi guest · myAccount · Log in
 SearchSearch   ProfileProfile   Log in to check your private messagesLog in to check your private messages   RegisterRegister 
What is tailwalking and what is wheelies?
Goto page 1, 2, 3, 4  Next
 
Post new topic   Reply to topic    iWindsurf Community Forum Index -> Windsurfing Discussion
View previous topic :: View next topic  
Author Message
sl55



Joined: 03 Aug 2007
Posts: 112

PostPosted: Thu Jul 28, 2011 12:15 pm    Post subject: What is tailwalking and what is wheelies? Reply with quote

What exactly is "tailwalking" and what's when they say the board is "doing wheelies"? Not sure if I spelled it right.
Any pics, vids?
Back to top
View user's profile Send private message
gk109



Joined: 22 May 2007
Posts: 94

PostPosted: Thu Jul 28, 2011 1:23 pm    Post subject: Reply with quote

when you get overpowered a couple things happen; the sail gets hard to control, you cant sheet in all the way and basically cant keep it locked in. when that happens you start to lose control of your board as well. The board will then start to rail up on the winward side because your fin is creating to much lift for you to keep the board flat. when it really gets bad the nose of the board comes out of the water a good bit and it begins to pretty much ride only on the tail. the board then gets very unstable from side to side and kind of "walks" back and forth. then you inevetibly catapult. you can do this on purpose and I guess thats what you could call a wheelie.
Back to top
View user's profile Send private message AIM Address
techno900



Joined: 28 Mar 2001
Posts: 3914

PostPosted: Thu Jul 28, 2011 1:31 pm    Post subject: Reply with quote

Here is a video that demonstrates some tail walking with formula boards. The best stuff is in the second half of the video.

http://www.youtube.com/watch?v=VEzjyPeOANo&feature=related

Tailwalking can occur with any board if there is enough speed. It can happen at relatively low speed on formula boards because of they are 100 cm wide and have 70 cm fins. Lots of lift from the big fin, plus wind under the board and it can take off. You have to keep a lot of downward force on the boom/mast/mast foot to keep the nose down.

I think it tends to happen most often when going fast on a full or beam reach and then turning the board into the wind (60 degrees off the wind) so that the apparent wind (wind speed + board speed) is increased significantly and quickly. It's common to "sheet out" and add more weight to the back foot when turning higher into the wind, this increases the likelihood of tail walking because of the reduced pressure on the mast foot.

Wheelies can occur as a result of tailwalking, but you can do them at slower speeds by transferring most of your weight to the back foot while lifting the front foot (in the strap) as well as pulling up on the boom and leaning back. This can lift the nose of the board off the water as much as a meter while sinking the tail at the same time. It can be used to slow your forward motion without turning or bailing off the board if you are approaching an obstacle. It's best to practice this AWAY from the shoreline or any other obstacle that may be in the way. Never do it while approaching people, if you goof up, you may kill someone.
Back to top
View user's profile Send private message
rigitrite



Joined: 19 Sep 2007
Posts: 514
Location: Kansas City

PostPosted: Thu Jul 28, 2011 9:42 pm    Post subject: Reply with quote

sorry guys, fins don't create lift: they're completely symetric. Please review Bernoulli's principle for an explanation of lift. I will agree that it feels like there's underwater lift being created, but lts an illusion.
Tail walking is definitely a result of a powered-up condition, but it's a combination of...6-8 separate forces (just a quick count off the top of my head). When the total of all resolved forces in the "up" direction exceeds the forces in the "down" direction, the board will start to rise up on the fin. When you dump the power in the sail the largest of the forces is greatly reduced and gravity pulls you back down. An explanation of how to resolve forces is beyond this discussion unless you've taken statics and dynamics. [/i]

_________________
Kansas City
Back to top
View user's profile Send private message
keycocker



Joined: 10 Jul 2005
Posts: 3598

PostPosted: Thu Jul 28, 2011 10:40 pm    Post subject: Reply with quote

You can tail walk on a small board with a excessively large fin. It tries to rail up on one side if you don't hold it very flat.This effect was useful to me in contests back in the late 70 early 8os in freestyle to score points by rail riding at speed.
You from KC rigitrite? I have sold gear there for twenty years.I gather the equipment from my place in Maui and from North Sports to consolidate to send to my store in Belize.
Back to top
View user's profile Send private message
DanWeiss



Joined: 24 Jun 2008
Posts: 2290
Location: Connecticut, USA

PostPosted: Thu Jul 28, 2011 11:40 pm    Post subject: Reply with quote

rigitrite wrote:
sorry guys, fins don't create lift: they're completely symetric. Please review Bernoulli's principle for an explanation of lift. I will agree that it feels like there's underwater lift being created, but lts an illusion.
Tail walking is definitely a result of a powered-up condition, but it's a combination of...6-8 separate forces (just a quick count off the top of my head). When the total of all resolved forces in the "up" direction exceeds the forces in the "down" direction, the board will start to rise up on the fin. When you dump the power in the sail the largest of the forces is greatly reduced and gravity pulls you back down. An explanation of how to resolve forces is beyond this discussion unless you've taken statics and dynamics. [/i]


Mmmm, not so much in the first two sentences, I think. Bernoulli may be correct or may be wrong, but he never said that only asymmetrical foils can create lift as far as I know. In other words, angle of attack does play a significant role in creating lift regardless of the shape of a foil.

A symmetrical foil does not need the lift from a hull to generate torque. All it needs is for fluid to flow past it and to be angled something other than in parallel to the flow.

_________________
Support Your Sport. Join US Windsurfing!
www.USWindsurfing.org
Back to top
View user's profile Send private message
techno900



Joined: 28 Mar 2001
Posts: 3914

PostPosted: Fri Jul 29, 2011 9:23 am    Post subject: Reply with quote

We have been through the physics lesson before, but the basic point is that big fins and speed will cause tail walking.

a fin too large given the width of the board and the speed will try to surface causing the board to rotate on it's axis, a phenomenon easily achieved with a longboard with a dagger board at speed, but still achievable with almost any board/fin combination with enough speed. Is it lift? Maybe or maybe not, but you will tail walk if you are going fast enough.

Rigitrite wrote:
Quote:
When you dump the power in the sail the largest of the forces is greatly reduced and gravity pulls you back down.

Correct in theory, but not in reality. When you dump power in the sail, by sheeting out, you also reduce the downward force on the mast foot and if you are heading up, the momentum of the board and the increase in apparent wind, plus the reduced downward force on the board = tailwalking. Sheeting out does work if sailing off the wind or a beam reach, but it can be a mistake if heading up an on a large board.
Back to top
View user's profile Send private message
isobars



Joined: 12 Dec 1999
Posts: 20132

PostPosted: Fri Jul 29, 2011 9:28 am    Post subject: Reply with quote

To most of us, tailwalking and wheelies are synonymous references to one's board nose or front bicycle wheel pawing uncontrollably at the sky. Regardless of the physics involved in the WSing scenario, it results primarily from too much power to control. I can see how the tailwalking term would also apply to uncontrollable rail-to-rail-to-rail-to-rail-to-rail oscillations, but that seems peculiar to superwide modern race boards with fins too long for the conditions, whereas the "wheelie" version of tailwalking can happen even with tiny 20 cm fins on tiny little sinkers when gusts get completely out of hand. I've never experienced the rail-slapping oscillations, as I've never sailed them picnic table thangs, but I've wheelied out of control plenty of times when gusts overwhelmed me and the smaller gear I was on. It's like planing; you'll know it when you feel it.

Mike \m/
Back to top
View user's profile Send private message
coachg



Joined: 10 Sep 2000
Posts: 3065

PostPosted: Fri Jul 29, 2011 9:30 am    Post subject: Reply with quote

I always thought tail walking was caused by too large a fin.

Really powered up with too small a fin-spinout. Really powered up with the right fin-go scary fast. Really powered up with too large a fin-tail walk.

At least that is my experience.
Coachg
Back to top
View user's profile Send private message
d0uglass



Joined: 28 May 2004
Posts: 1278
Location: Bonita Springs, Florida

PostPosted: Fri Jul 29, 2011 9:35 am    Post subject: Reply with quote

I'm with Dan Weiss- Fins can create lift even though they're not asymmetrically foiled like an airplane wing. They just have to be at an angle to the water flow. Imagine dipping one into the water off the side of a fast moving boat. Any little tilt or twist to the fin would have it wanting to veer and leap in another direction.

When a windsurf board is tilted to leeward and the nose is riding high, the fin is angled somewhat like the wing of an airplane taking off, so it's definitely lifting vertically somewhat as well as resisting horizontally.
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    iWindsurf Community Forum Index -> Windsurfing Discussion All times are GMT - 5 Hours
Goto page 1, 2, 3, 4  Next
Page 1 of 4

 
Jump to:  
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 vote in polls in this forum
You can attach files in this forum
You can download files in this forum

myiW | Weather | Community | Membership | Support | Log in
like us on facebook
© Copyright 1999-2007 WeatherFlow, Inc Contact Us Ad Marketplace

Powered by phpBB © 2001, 2005 phpBB Group