Zipp what are you doing

[pdlpsher1]

https://www.youtube.com/watch?v=9I3pnXWpDvI

[RimClencher]

The real question no one is asking: How many watts does this save at 40 knots with 5 degree cross-current?

[wingguy]

The real question no one is asking: How many watts does this save at 40 knots with 5 degree cross-current?

Um, no-one's asking it because Zipp have already said what their watt saving claims are.

[Bondurant]

Whoosh!

[Multebear]

The real question no one is asking: How many watts does this save at 40 knots with 5 degree cross-current?

Um, no-one's asking it because Zipp have already said what their watt saving claims are.

I think you missed the point...

[wingguy]

The real question no one is asking: How many watts does this save at 40 knots with 5 degree cross-current?

Um, no-one's asking it because Zipp have already said what their watt saving claims are.

I think you missed the point...

Hah! Yeah now I see it. Sorry, I'm not nautical

[cyclespeed]

Am I alone in thinking that Zipp have thrown away the smooth, almost zero rotational drag of a normal rim, and replaced it with a rim that has big chunky steps in it that must present more resistance to ROTATIONAL drag?

Call me crazy but I'm pretty sure Zipp will have tested it while it was moving. They kinda employ a lot of people to think about this stuff, y'know?

Why then shoot yourself in the foot by making a rim that must be less aero efficient in a spinning situation?

Because they haven't because it isn't

You really believe everything that Zipp tells you and swallow it up? Did you buy one of those Pinarello wavy forks? Do you think they're going to highlight any possible negative aspects to this new design?

And given that they do not even mention spinning efficiency, how do you know what their position is?

[wingguy]

You really believe everything that Zipp tells you and swallow it up? Did you buy one of those Pinarello wavy forks?

Haaahaha dude is that all you've got? That sucks as a PA, let alone as a serious response.

And given that they do not even mention spinning efficiency, how do you know what their position is?

I would say that they don't give a flying *f##k* what the 'spinning efficiency' is, since unless you're looking to break some new Zwift records on your rollers the stationary 'spinning efficiency' of the rim has absolutely sweet *f##k* all to do with the aero efficiency of a rim that is moving forwards through the air

Further, since the stated benefit of the rim design would only happen while the rim is actually turning then again, yeah - I'm pretty sure that they figured out how the rim compared while it was actually turning.

[cyclespeed]

Why do you always become so aggressive so quickly? I think you need to address that. You managed to get a recent thread shut down because of it. Try and stay calm.

So answer me this;

if they don't give a flying 'expletive' what the spinning efficiency is, then why go to the cost and complication of using bladed spokes? Why not just fit chunky round ones? After all, bladed spokes increase the side area that side winds can act upon, right? So why use them?

[wingguy]

Why do you always become so aggressive so quickly?

Same reason you decided to get so passive-aggressive in your last reply, probably. Ask yourself why you felt the need to do that, then apply the answer.

if they don't give a flying 'expletive' what the spinning efficiency is, then why go to the cost and complication of using bladed spokes? Why not just fit chunky round ones? After all, bladed spokes increase the side area that side winds can act upon, right? So why use them?

Because spokes are moving through the air on a moving wheel.

Now just for a moment, drop your pre-conceived notions and actually picture they way that a stationary but spinning rim encounters airflow and they way that a moving rim encounters airflow. Can you do that and then, with a straight face, tell me that there is the slightest similarity between the two cases?

[cyclespeed]

Same reason you decided to get so passive-aggressive in your last reply, probably. Ask yourself why you felt the need to do that, then apply the answer.

Well as least it's just passive-aggressive as opposed to plain old 'aggressive'.

Because spokes are moving through the air on a moving wheel.

Now just for a moment, drop your pre-conceived notions and actually picture they way that a stationary but spinning rim encounters airflow and they way that a moving rim encounters airflow. Can you do that and then, with a straight face, tell me that there is the slightest similarity between the two cases?

Of course the dynamics are different between a stationary spinning wheel and a moving one, it becomes much more complicated.

But that does not change the fact that the spinning elements of the wheel, notably the rim and the spokes need to spin through the air efficiently, regardless of whether that air is turbulent or laminar or coming past at 0, 20 or 40km/h. Otherwise, once again, why bother using bladed spokes?

[spartan]

inconvenient truth about the new zipp. they work but......the competition does it better and for a lower cost.

german tour mag international issue 8 did some aero testing on the new wheelset. they included a new metric crosswind stability.

Code: Select all

                   zipp404 firecrest    zipp303     mavic cxr60       bora50   reynolds58aero
aero                 222 watts           225w         222             224.7              225
crosswind            3                    2.3          2.0            2.0               1.0

sooo what can we conclude elliptal rims have a definite advantage in cross wind stability

mavic is the best for aero(matches zipp404) and good stability in crosswind. the reynolds is brilliant scoring a 1.0 for a 58mm rim width. the new zipp 454 is supposed to have crosswind stability of a zipp 303. all that marketing bs and they are still not as good reynolds wheel.

*ps they did not bother testing lightweight/corima wheels.

[wingguy]

Well as least it's just passive-aggressive as opposed to plain old 'aggressive'.

Just? Did you notice that although you intentionally insulted me, I didn't insult you, I just happened to use the word *f##k*?

If you think you're standing on the moral high ground there I'd say you were very much mistaken.

But that does not change the fact that the spinning elements of the wheel, notably the rim and the spokes need to spin through the air efficiently

Yes, it does. It really, really does. If you are just spinning the wheel then the inner diameter of the rim (in fact, any of the rim at all) contributes nothing but surface drag to slowing the wheel down. Unlike the spokes, the rim effectively has zero cross-sectional area - it is not in the wind. When the wheel is moving forward then the inner diameter of the rim is suddenly a large part of the cross sectional area of the wheel sitting there in the air flow.

It's absolutely, positively, completely different.

Otherwise, once again, why bother using bladed spokes?

Not because they're more aero when the wheel is spinning, but because they're more aero when it's moving. They still do affect a spinning wheel, because they (unlike a smooth rim) are presenting cross-sectional area to the airflow in that situation, in a somewhat similar way to when they are actually moving.

[Nefarious86]

Surely a spin down test could resolve this argument

[steventran]

Aero is uglything


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