I sold my 404's two summers ago to buy a 808 front to go with a Zipp disc I had. I never road faster than when I had my 404's. After owning all of the Zipp and most of the Hed wheels I can honestly say that the 404's were my all time favorites. Don't know why. I really wish I would have kept them. Do yourself a favor and hang onto yours. There is nothing to be gained by switching to other wheels.

Its been a while since I've been to physics class but there seems to be a lot of misuse of the concept of watts on this message board.

If it takes less watts to move a wheel through space there are only two things that I can think of that could have happened
1. its more aerodynamic - the force of wind impeding its movement is less.
2. there is a lower rolling resistance.

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Erik
Strava

thanks a lot i appreciate that. I will hang on to my 404's. i got them on the advice of a guy who is a Kona Qualifier year after year. He is much faster than me, he is sponsored and he rides 404's he said they are his favorite wheels, although he rides the Z4's!!!

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Like T says, "Remember it is all about the Bike because it is all about the Run!"

it worked on me! i ran out and bought BR disc and 50 front!!! thanks, john

Amen to that. The only other thing I would add is bearing friction, but otherwise I agree 100%

Or you can just put the things on with electrical tape. It works just fine.

I leave it to you guys to ponder why I go to most races with an 808 that has CH Aero covers taped on, and leave the Zipp clincher disk and the Carbonsports Lightweight disk at home.


-- jens

Why doesn't a well fitted cover make that disk sound?

this thread seems to have died over the weekend but some questions remain. Alvarov asked an interesting question and a couple of weeks ago I asked about the relative aero performance of various clinchers disks but didn't get any manufacturer replies.

Last week I asked pretty much the same question of Zipp via their tech. inquiry service on the website but have not received a reply to date.

I suppose it is for the versitility depending on the conditions (although I know of very few conditions that would warrant not having a disk, uless it is not allowed; in which case you would not bring it); so now that I think about it, I have no idea why you would do that. Now you have me curious. Why would you not take a disk rear wheel when you have two discs at your disposal????? The ONLY reason that I can come up with in the past two minutes of thinking about it is that it packs easier in the bike case...is this right?

Personally I have a rear zipp 280 rim with ultralight aircraft covering epoxied to the rim and hub flange adapters (which I constructed) which functions as my full time disc. With the rim/ sapim x-ray spokes, hexhead nipples (for truing from the spoke hole) and american classic hubs, it made a lighter disk than was available at the time, at about 1/10th the cost (I got a deal on the pieces).

Stephen J

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I believe my local reality has been violated.
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Happiness = Results / (Expectations)^2

There are a couple of reasons: 1) The 808 has a powertap hub (I've taken the SRM off so I can use various funky cranksets 2) The 808 with covers is faster.

In 0 yaw field tests, the disks all come out pretty close. On real world courses with winds, the 808 with the disk covers has beaten the others every single time. Don't know why that is, because it looks goofy. But it it has been pretty consistent. Most recently, I rode a 54:18 40K with only 252 watts. And that's with my less aero position.


--jens

54:18 40K with 252 watts?

Wow! Man you are one "slippery" dude :)

Any reason you don't go with an even deeper front wheel (i.e. Blackwell 100 or PX 101)? I'm sure you can handle the winds easily.

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Fatigue is biochemical, not biomechanical.
- Andrew Coggan, PhD

thats pretty interesting...

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Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

The BW100 demands a pretty narrow tire, i.e. 20c or better yet, 19c. I don't know, but I would guess the PX is similar. Most of the TTs around here are on roads that are a little too rough for that.


-jens

Ah Ha! I have a theory...Maybe, a spoked wheel gives you a wheel with very CLOSE aerodynamics to a disc, but the real world Crr is lower (given the 'suspension effect' that a spoked wheel gives); as I noticed that you said the 808 was FASTER, not MORE AERO. Another possibility is that since you are riding with power meter with the 808, you are able to ride more efficiently than with the other wheels, thus making you faster as well (I forgot about the power meter in my last post).

Stephen J

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I believe my local reality has been violated.
____________________________________________
Happiness = Results / (Expectations)^2

interesting theory ... I wonder what the road surface on Jens' skunkworks testing facility is like?

Most wind tunnel data is fundamentally flawed. Wind, because it lacks
the density of other substances, is frequently controlled by extrinsic
factors. A riders movement, for instance disrupts wind, as does low
hanging trees, the refraction of the sun's raise, and (it's now
indisputable after years of debate), the tides. Obviously, less wind
resistance will equal faster bike times because, despite the chaotic
nature of wind, over a long course the laws of probability all but
guarantee the chaos will balance into some semblance of normalcy. The
problem is, in wind tunnel testing, the controlled circumstances often
eliminate a lot of these normalizing factors, so select extrinsic
factors have the potential to control a test's outcome (for instance a
high tide).

As a result, I've been working with pro teams in a hydro tunnel.
water flows past riders and the frames in the same manner as wind but
its greater density gives it higher consistency and more reliable test
data. Our hydro tests are race proven and have yielded some
surprising results. First, Zipp wheels, at anything over 5 degrees of
yaw, drop resistance at all times except in direct sunlight, at high
noon, when the Pacific is at its lowest monthly tide. In most typical
morning race starts, when tides are most often high and the sun's rays
are less direct, Easton wheels present the optimum race conditions.
Most participants can expect to save 5-10% on their bike leg.

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team website: http://snappletriteam.com/

team blog: http://snappletriteam.com/?page_id=10

How do you correct for all the scuba gear on the riders? When we were testing various horses for water polo I can tell you the scuba gear was a major problem...

Wait!

How are you extrapolating water resistance results to determine what time of day air will flow past the bike best? How would the tides affect the localized wind resistance presented to a bike?

Is this a clever joke? haha

ok..yes that a joke...lol

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Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

The most difficult aspect of working with professional riders in the hydro tunnel was getting the comfortable with the process. There were doubts as to the validity of the process, but as I think I made clear in my earlier post our results cannot be disputed.

This isn't meant to be rude so please don't misinterpet but your question regarding scuba gear shows a clear lack of understanding of the process and how a hydrotunnel really works. Also, I think horses and water polo sounds like some sort of attempt at levity and I am trying to engage in serious scientific research into what we will make us all faster and it would be appreciated if we could all stay on the straight and narrow in this thread.

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team website: http://snappletriteam.com/

team blog: http://snappletriteam.com/?page_id=10

"First, Zipp wheels, at anything over 5 degrees of
yaw, drop resistance at all times except in direct sunlight, at high
noon, when the Pacific is at its lowest monthly tide. In most typical
morning race starts, when tides are most often high and the sun's rays
are less direct, Easton wheels present the optimum race conditions.
Most participants can expect to save 5-10% on their bike leg."

This is why I always ride my Zipp wheels while holding a carbon dimpled umbrella.

I can see that this group needs a lot of educating.

We do not need to input controls regarding the time of day into the hydrotunnel in order for it to yield reliable results. Wind is the just the flow of air and it is influenced by a number of factors -- some of which I discussed above. Wind levels will change from day to day and from place to place, but those levels (and this is the important part) are impacted by a number of different factors. These factors do not exist in a vaccuum -- hence differing wind speeds from differing directions.

The problem with wind tunnel testing is that manufactured wind is moving at static levels in static directions. As we all know from experience on the bike, the wind never flows at a constant speed in a constant direction. I may be more in tune with the wind than others given my vast experience, but even a wind that feels steady from a directional point will have minor shifts in its heading.

The hydrotunnel takes all of these factors into account and generates results that are reflective of real world riding. Riding in a tunnel with a 30mph wind in your face has nothing to do with what we will see out on the course.

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team website: http://snappletriteam.com/

team blog: http://snappletriteam.com/?page_id=10

you haven't even mentioned relativistic effects. Clearly a major source of error ....

And the earth's surface doesn't even present an inertial reference system so even Newton would be displeased.

You know the rules around here, it there are no pictures, it did not happened.

I was hoping to avoid dropping names, but here's Lance celebrating 7 consecutive TdF victories:



Here's Lance in the Hydro Tunnel:





Let me know what more is needed.

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team website: http://snappletriteam.com/

team blog: http://snappletriteam.com/?page_id=10

....mother of god

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Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter