wind pattern from a rotating wheel (m/c)

Hans Blom · October 31, 2006, 03:51:11 AM

I was wondering if anyone has any knowledge of the effect that the rotation of the front wheel(tire) has on the flow of air around the front tire. I have tried doing some googling of rotating bodies and such but haven't really come up with anything. Just wondering things like if the rotation has an affect on the height of the resulting dead space behind the wheel and the same for the width. Obviously the coarseness of the tread would also have some effect, but how much?? Probably not much here, but you would think a slick tire would have slightly less turbulent air at the surface of the tire, maybe making a smaller area inside your shear line, which could be good or bad depending on the tire size and the bike itself....
Hans

1212FBGS · October 31, 2006, 08:04:01 AM

yes
I have a lot of tunnel data and great pix of a rotating tire being smoked in a tunnel. i still cant figger out how to post pixs on this site yet, if someone can help tell me how then i'll let everyone see 'em

Sumner · October 31, 2006, 08:38:51 AM

Quote from: 1212FBGSyes
I have a lot of tunnel data and great pix of a rotating tire being smoked in a tunnel. i still cant figger out how to post pixs on this site yet, if someone can help tell me how then i'll let everyone see 'em

Kent you have to either:

Upload them from your computer using the "add attachment" option when you post,

or

you have to have them on a site that is on the internet and then you post a link to them on that site such as this:

{IMG}]http://picture address{/IMG}

replace the { with [ in the example about and } with ]. To put in the link go to the picture you want to link to and "right click" on it then go to "properties", next highlight the "address (URL)" with your mouse and right click and copy the address and past it into the above where it says http://picture address.

It sounds complicated, but it is easy once you have done it a couple times.

Another option is to go to "viewer picture post" on the site and do it there.

Or last e-mail them to me or someone else and have them post them. I'm on dial up, so if they are a couple meg's forget me

.

........and yes I would like to see them.

c ya,

Sum

hitz · October 31, 2006, 08:52:23 AM

Quote from: 1212FBGSyes
I have a lot of tunnel data and great pix of a rotating tire being smoked in a tunnel. i still cant figger out how to post pixs on this site yet, if someone can help tell me how then i'll let everyone see 'em

Somebody please help Kent post these pictures. I've been looking all over for a tunnel picture of a rotating tire. I haven't had much luck posting pictures here either.

Kent,
If you still don't have any luck with posting I'd like to PM you with my E-mail address.

Harvey

Hans Blom · October 31, 2006, 12:57:58 PM

I would love to see that , I'll be watching in anticipation! is this work you did yourself or some other data?

JimW · November 02, 2006, 07:20:49 PM

I have heard that the 'pumping losses' can be significant. (you might try googling 'aerodynamic pumping losses'). It was recommended to fit a piece of metal or plastic, angled and contoured to closely fit the tread of the tire to 'shave off' the air that would otherwise just go around and around. Haven't tried it, but intend to.

Thanks,
Jim.

John Noonan · November 02, 2006, 10:11:26 PM

Kent,

Send them to me and I will "host and post" them for you.

Thanks,

J

JackD · November 02, 2006, 11:27:57 PM

The first use I saw of the "PUMPER STOPPER" inside the fender was soft
plastic that would wear away as the tire would expand at speed and take
the proper shape to form a seal.
It was out of sight and not shown to others.
That was in 71 and tested by a still prominent Pro Stock MC team.

Hans Blom · November 14, 2006, 02:34:52 PM

Kent, any luck with the aero info?

Thanks, Hans

Super Kaz · November 20, 2006, 04:10:04 PM

Quote from: JackDThe first use I saw of the "PUMPER STOPPER" inside the fender was soft
plastic that would wear away as the tire would expand at speed and take
the proper shape to form a seal.
It was out of sight and not shown to others.
That was in 71 and tested by a still prominent Pro Stock MC team.

JackD,
I'm gonna have to call George Bryce and ask him about that one

: .As None of the School Bikes had them?I got my NHRA PSM Lic from him last year

!
I'm pretty close to the PSM Chassie God so I'll call him and ask him also!

I've got to go against those Turbo Hayabusa's with my Little V-twin"DOHC",and NEED ALL THE HELP I CAN GET

John Noonan · November 27, 2006, 02:54:00 PM

Quote from: Super Kaz
Quote from: JackDThe first use I saw of the "PUMPER STOPPER" inside the fender was soft
plastic that would wear away as the tire would expand at speed and take
the proper shape to form a seal.
It was out of sight and not shown to others.
That was in 71 and tested by a still prominent Pro Stock MC team.
JackD,
I'm gonna have to call George Bryce and ask him about that one : .As None of the School Bikes had them?I got my NHRA PSM Lic from him last year !
I'm pretty close to the PSM Chassie God so I'll call him and ask him also!
I've got to go against those Turbo Hayabusa's with my Little V-twin"DOHC",and NEED ALL THE HELP I CAN GET

Kaz,

He is not talking about Star racing..

J

JackD · November 27, 2006, 03:43:18 PM

Enough people saw it from 2 other OEM groups that it was not a speed secret or I wouldn't repeat it..
They may have developed other methods since but it did work.
You don't think they would let you go to school on a top of the line bike with all the tricks do you ?

Super Kaz · November 27, 2006, 04:07:37 PM

Quote from: JackDEnough people saw it from 2 other OEM groups that it was not a speed secret or I wouldn't repeat it..
They may have developed other methods since but it did work.
You don't think they would let you go to school on a top of the line bike with all the tricks do you ?

Chip's Bike was there

.It was being Bought by The Big Cheese of S&S

.There were a couple Executives
from S&S Taking the Class with me

.As George wanted them to know what it was Like!

whitworthsocket · December 06, 2006, 05:25:40 AM

Im not sure about the effects of plastic rubbing against rubber.
Is that going to create large amounts of heat anf static electricity?

Are there any documented aero performance gains?

Regards Whitworthsocket

JackD · December 06, 2006, 06:49:30 AM

The material used for the gate is soft polyethylene and only actually touches the tire at the highest speed attained with no friction loss and resultant heat.
The effect is to stop the tire from pumping air between the fender and the tire.
The results will vary with the application and speed.
The effect is measurable on a test stand but hard to measure from run to run on a bike.
If you want to stop the air, there you have it.

News:

wind pattern from a rotating wheel (m/c)

Super Kaz

Super Kaz