No...we don't "know"...but the suspicions are VERY strong. Combine the anecdotal account of bigadam's "friend" with the fact that in the first pic you can see the far right edge of the Zipp logo on the wheel...and things start adding up pretty quickly :-)


I have no idea...Joshatzipp...paging Joshatzipp...;-)

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http://bikeblather.blogspot.com/

Isn't Bontrager doing something similar in conjuction with Hed, a bulge at the rim? I believe Hed is doing something similar with their new superlite disc but with a lenticular shape after the bulge.

The sub-9 disc in the picture on Pezcyclingnews.com is definitely what I saw at IML. If you look closely at the pez picture, you can see that the wedge shaped carbon "plates" curve at the bottom just before they meet the hub. On the current model, the "plates" are straight and overlap a little where they mate with the hub. This difference was exactly the same as the one in Louisville.

I was told that the new wheel wasn't available yet. It was definitely a finished product, though.

Richard Armstrong

are you sure the base bar isn't available? I have seen guys with them on their bike. Maybe just big tri shops pre ordered them all?

Dan
http://www.aiatriathlon.com

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http://www.aiatriathlon.com

I was at SBR in NYC on Sunday and they said it was not available. Was not able to get to my favorite shop (R&A), so I not sure if that was true. Plus I have not seen anything online yet.

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Pasadena Tri Club

The zipp base bar is absolutely available in my area, as well as online.

Bob

I just checked both R&A and Nytro's websites, they both have the Vuka aerobar but neither has the new Vuka base bar yet.

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Pasadena Tri Club

All3 Sports.c om marks them as "In stock and ready to ship." Plus, if you called your local shop, they can probably order it from Zipp.

Bob

What, you're saying that CdA can vary as a function of yaw angle? Fancy that...

;-)

Yes, that's true...but what I was actually getting at was that the variation in CdA with yaw could be different with certain equipment depending on whether you're yawing up away from zero, or back down towards it.

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http://bikeblather.blogspot.com/

As Chet Kyle emphasized in an article in Cycling Science >15 y ago. The question, then, is why some people (e.g., Jobst Brandt) refuse to acknowledge this well-established fact.

(Note that I snipped your comments about how the approach to a particular yaw angle may matter to better make my point. :-))

wow, I go to eurobike and we haven't even shown this thing yet and you guys are all over it! the disc does combine a honeycomb core center with hollow perimeter hoop...no spokes. the shape is the same one we developed in feb at the SD wind tunnel and it does in fact create -80 grams of drag at 15 degrees yaw using the 30-0 test protocole tom talked about. the negative drag window extends from 11-18 degrees and has 30-40 grams lower drag than any flat or lens disc between 0 and 20 degrees. using the 0-30 tunnel protocol it looks even better but experience tells us that protocol yields overly optimistc data.

we also tried doing it with lens center as well as a modified lens with our tire blending geometry and the results were very good wheel only but suffered in a bike..we think from the disc skin being too close to the seatstays.
other than being sick fast the other benefit is comfort and handling, it has almost identical vertical compliance to the 808 which is to say vey good. one of oue testers said it best when he told me that it was the most comfortable IM wheel he's ever been on and at the same time handled like a crit wheel in the corners...needles to saay we are quite excited!

we have a press coference tomorrow were we are releasing 8 other new products...some of which will be equally exciting!!
stay tuned!
[i]

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http://www.SILCA.cc
Check out my podcast, inside stories from more than 20 years of product and tech innovation from inside the Pro Peloton and Pro Triathlon worlds!
http://www.marginalgainspodcast.cc

Hmm, it just dawned on me that I have wind tunnel data addressing this very question!! I'll have to go back and take another look at what happened at higher yaw angles...my interests have been strictly at the low end.

Ummm....curmudgeonliness?? (is that a word?) :-)

Actually, for Jobst, on his steel road bike with 36 spoke wheels, perhaps the simple assumption of a cylinder is appropriate. For a good TT or Tri setup, not so much...

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http://bikeblather.blogspot.com/

:) I wondered if you would chime in on this.

Well, I'm glad you tested that too. It sounds like it did a little better, at least as a standalone, eh? (I think that's what Hed found). I'm going to go out on a limb here and say that, at least on my bike, a lens with a bump is measurably faster than a flat disk with a bump.

I'll also venture the CHAero lens (or "cone") is superior to conventional lens disks, since it has some conical shape on the drive side, which the others don't (or at least they have relatively little).


-jens

Okay, here you go: changes in drag* from 0 deg of yaw going out to 2.5, 5, and 10 deg, then back again for the same rider on the same bike in the same position but using a flat disk and a "bump" disk (but also different front wheels):

"bump" disk:

23
-31
-175
-50
-19

flat disk:

-19
-71
-51
-15
40

So, the "bump" disk shows a nice reduction in drag as a function of yaw angle, which is maintained even on the return trip, i.e., from 10 to 0 deg of yaw. When using the flat disk, however, there is less of a reduction in drag as a function of yaw angle, and this benefit is clearly greater when going from 0 to 10 deg of yaw compared to the opposite. (IOW, with the flat disk wheelset it appears that once flow is detached it is unable to re-attach.) These results are consistent with Zipp's claims that adding a bulge just below the brake track makes a wheel less likely to "stall".

*Data in grams, body axis model.

Us ST spies/speculators are pretty good, huh? :-)




Interesting. Was this a shape closer to a complete lens shape...or was it similar to an 808 with a cover? I'm a little confused on your description. Thanks.

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http://bikeblather.blogspot.com/

we tried both the 808 with cover type shape as well as a more 808 morphed into lens type disc like what hed is doing and the concept we ended up with was faster either of these, both in the bike and wheel only. in fact the design we ended up with set the all time record for drag at that tunnel as mentioned in the triathlete article...so no, the other concepts were good, but not better than the one we took to production. my point was really that the other designs were also good, but this one was best in both testing types.

and the reason the 808 with covee is faster than the clinchee disc is because of the 808 tire blending shape of the 808 tuby and not because of the conical nature of the cover...or at least that's what we learned in our last 40 hours in the SD tunnel

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http://www.SILCA.cc
Check out my podcast, inside stories from more than 20 years of product and tech innovation from inside the Pro Peloton and Pro Triathlon worlds!
http://www.marginalgainspodcast.cc

Ah good, you cut straight to the point. As you guessed, that is what I tested (808 tubular + cover) vs. clincher disk. Now I'm going to have to buy your !#!$#!#! tubular 'bump' disk just to make sure... ;-)


-jens

p.s. I met Cees in person last week. His name is actually pronounced "Case," as in "Case Beer" A very nice guy. Judging from who has chosen to work with him, he knows a lot.

Josh, I may be missing something, but surely to minimise the instability you want the wall to fall away from the flow as slowly as possible? Thus surely instead of having a bulge, an inverse conical disc (narrowest at the hub) would be best?

Josh: So, will there be a Zed Tech version of this disk as well?

Bob

So we saying that tubulars are faster than clinchers from an aero perspective??... Is this of greater magnitude than clinchers supposed better RR??... this'll run and run .

Jens,

Where did you get your 808 cover?

Depends -- what tire, on what wheel? Some tubular tires are so slow that, if you mount them on the most aero wheel in existence, they are slower than spoked training wheels with good clinchers. The Crr losses can easily out-trump the aero gains.

We find Crr differences among very popular tires in the 5-10 watt per tire range -- more than the drag differences between various brands/models of high-end aero wheels. Tire selection is more important than the choice of, say, a Hed3 versus an 808.

Even the best tubulars are too slow (high Crr) if they're not glued on properly.