Dimples?

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Simon BP
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by Simon BP

If dimples are so good on Zipp wheels and cycling clothes, then why dosen't we se any dimpled framesets, handlebartape, seatposts, helmets, aso.. ?

raptor3x
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by raptor3x

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Mottsauce
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by Mottsauce

Because the dimples aren't that great. In golf balls, dimples provide lift, not aero properties; so unless you want to fly away....

If they were so good then Zipp wouldn't cover them up with their giant non-dimpled glossy stickers :roll:

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Simon BP
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by Simon BP

then why even bother putting them on? It looks like crap, and if it doesn't even help, then I can't se the mening of even having them? :S

rustychain
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by rustychain

Dimples are the most important and revolutionary marketing invention of our time




:roll:
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Stolichnaya
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by Stolichnaya

Because dimples distinguish Zipp as different - using different technology. Much of it is marketing hype that a lot of consumers buy into. Seems to have been successful move for Zipp.

raptor3x
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by raptor3x

Mottsauce wrote:Because the dimples aren't that great. In golf balls, dimples provide lift, not aero properties; so unless you want to fly away....

If they were so good then Zipp wouldn't cover them up with their giant non-dimpled glossy stickers :roll:


Dimples do not provide lift, they reduce the pressure drag on a bluff body.

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Mottsauce
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by Mottsauce

raptor3x wrote:Dimples do not provide lift, they reduce the pressure drag on a bluff body.


"The dimples, paradoxically, do increase drag slightly. But they also increase "Magnus lift", that peculiar lifting force experienced by rotating bodies travelling through a medium." http://math.ucr.edu/home/baez/physics/General/golf.html

The source is from 1997, so the physics may have been better explained in the last decade, but this is the impression that I was under. Sorry if I'm out of my league here.

Leloby
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by Leloby

DIMPLES.......AAAARRRGGGGHHHHH!

Not more dimples!

Please!!!!!

I got a pair of Continetal Competitions the other day and I was looking at the dimples (rather - 'pimples') on them thinking....'I wonder if they make any difference...'

I never thought it would happen but that Zipp crowd have altered my bloody brain :evil:

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zebragonzo
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by zebragonzo

Dimples convert laminar flow to turbulent. Turbulent air 'sticks' to surfaces better and delays flow separation thus reducing pressure drag.

Dimples are needed on rotating objects so that an edge will be presented whatever the orientation. A unidirectional object can have the same effect with a single groove perpendicular to the flow.

It's effect on wheels is questionable.

This too:
Stolichnaya wrote:Because dimples distinguish Zipp as different - using different technology. Much of it is marketing hype that a lot of consumers buy into. Seems to have been successful move for Zipp.
Dimples: Laminar flow separates more easily from a surface than turbulent air. Delayed separation reduces drag. A groove perpendicular to the flow triggers laminar to turbulent conversion. A spinning object uses dimples so an edge always faces the flow.

cswi9367
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by cswi9367

one reason other mfrs dont do it is because zipp has a patent on it.

a dimpled wheel vs non dimpled wheel in a wind tunnel does show advantages. zebra mentions why.

it makes sense. perfect sense. object must be in motion to gain advantages of dimpling.

also...zipps stickers do cover the dimples, but they sink into the dimpling, so they do cover them up so there are no dimples in the sticker area. at least mine are that way . i can feel the dimples through the stickers very easily, just as much as where the sticker is not located.

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HammerTime2
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by HammerTime2

Leloby wrote:I got a pair of Continetal Competitions the other day and I was looking at the dimples (rather - 'pimples') on them thinking....'I wonder if they make any difference...'

The Conti Comp pimples serve as a tread wear indicator, although there is plenty of tread left when the pimples are worn off.

gumgardner
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Location: Pittsburgh

by gumgardner

How long before Zipp can move away from the dimples? They have so much invested in this concept. How do they ever break away from it?

Leloby
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Location: UK

by Leloby

It will be their swansong.

Or will they go for 'pimples' next? Those Contis feel fast!

The best use of dimples I have ever seen are on the cheeks of the girl 3 doors down from me. But thats another story.

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jjmstang
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by jjmstang

Leloby wrote:
The best use of dimples I have ever seen are on the cheeks of the girl 3 doors down from me. But thats another story.


I bet she's a fast one too !!!!! :lol:
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