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Re: The bike that slowtwitch built [chadman_98126] [ In reply to ]
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So are those wheels actually faster now?
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Re: The bike that slowtwitch built [jjstains] [ In reply to ]
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Really cool brake. Have check the HED third brake lever?

Formely stef32
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Re: The bike that slowtwitch built [jjstains] [ In reply to ]
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jjstains wrote:
So are those wheels actually faster now?

TBD. on paper they're the same layout, configuration, sizing, etc. as the dimples now on Zipp wheels (circa 2005 and later?), but ultimately testing it is the only truth.
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Re: The bike that slowtwitch built [jjstains] [ In reply to ]
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Interesting question. They're probably slower than they were under 5 degrees yaw, but faster than they were >5degrees yaw. You'd have to test to find out.

I did get my hands on some riblet film a while back and tried applying it to my fork, but it wouldn't stick. I'm not sure if it was too old and the adhesive lost some of its agressiveness, or if the leading edge curvature had a radius that was too small, but it peeled back at the leading edge and I ended up removing it.

Riblet film is tricky...my understanding is you have to get the riblets in exactly the right orientation or else you're literally wasting time, not to mention you'd have to match the riblet size to your flow Reynolds # and I have no idea which size riblets were on the film I had.

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Re: The bike that slowtwitch built [ZackCapets] [ In reply to ]
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ZackCapets wrote:
Interesting question. They're probably slower than they were under 5 degrees yaw, but faster than they were >5 degrees yaw. You'd have to test to find out.


even at under 5 degrees they may be faster -- it depends what kind of flow separation there is and what their performance profile is - but ultimately that'll only come out with testing.

every reason to believe they're at least performant with 2005-2007 Zipps with a similar dimpled profile, but someone with better domain expertise can chime in.
Last edited by: chadman_98126: May 16, 13 13:10
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Re: The bike that slowtwitch built [ZackCapets] [ In reply to ]
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Hello -

I think everyone is forgetting a few things.
If the lambda is less than the 12 degrees of yaw at 40KM it doesn't matter if you are running a 650 or 700. Even though you considered the NACA 20 I think it's more important to realize that the flux capacitor needs to be running at lamda -12 degrees to hit the apex of the flying foam airfoil. If you reverse the HTA you will be better off. Makes sense, right?
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Re: The bike that slowtwitch built [chadman_98126] [ In reply to ]
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chadman_98126 wrote:
ZackCapets wrote:
Interesting question. They're probably slower than they were under 5 degrees yaw, but faster than they were >5 degrees yaw. You'd have to test to find out.


even at under 5 degrees they may be faster -- it depends what kind of flow separation there is and what their performance profile is - but ultimately that'll only come out with testing.

every reason to believe they're at least performant with 2005-2007 Zipps with a similar dimpled profile, but someone with better domain expertise can chime in.

Agreed with your first statement about testing. It's a very complex problem given that the surface in question is rotating. Some sort of circumferential riblets might be the ticket, if such a thing could be created.

As for comparability, the H3 is one of the best wheels out there at 0deg when matched with a semi-narrow tire from what I've read, but at yaw it seems deep wheels with less "spoke area" test better.

To the "flux capacitor" guy, I went to school for Aero Eng. and have been a student of the sport of tri for many moons now so I give myself free license to nerd-out on occasion.

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Re: The bike that slowtwitch built [ZackCapets] [ In reply to ]
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ZackCapets wrote:


To the "flux capacitor" guy, I went to school for Aero Eng. and have been a student of the sport of tri for many moons now so I give myself free license to nerd-out on occasion.


+1 :-)

and I only play one on TV.


(did do aero though, and occasionally put it into practice: http://clarianpower.com/wind.html)
Last edited by: chadman_98126: May 16, 13 14:14
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Re: The bike that slowtwitch built [chadman_98126] [ In reply to ]
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Im not hating....I just wish i knew what you were talking about!
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Re: The bike that slowtwitch built [maverick04] [ In reply to ]
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maverick04 wrote:
Im not hating....I just wish i knew what you were talking about!

that's why they invented the question mark. ;-)
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Re: The bike that slowtwitch built [damon_rinard] [ In reply to ]
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Kind of OT, but since the topic of cylinder aerodynamics and surface treatments was brought up...

I'm usually wearing leg warmers for my TT's (partly because I'm always cold, partly because it IS always cold were I live) and I'm wondering why no one has made any aerodynamic leg warmers. Either super-smooth and/or with some trip wires or the like. There should be some gains to be made with those two big cylinders (OK, my legs aren't that big, but still) sticking out in the more or less free air stream.

From a quick napkin calculation I get something around ~1000g of drag from the legs, så just a few percent drag reduction would be meaningful. Of course, with trip wires (which I knew Smart Aero Technology looked into on their long socks) it could be tricky with the leg angle changing both between riders and within a pedal circle.

Also, I guess the pro's would never wear them because the cycling culture forbids you to ever wear anything but bare legs in a race, but for those of us who doesn't care so much about the culture and more about speed it would be nice.
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