Let me check on that.

Although the rim shape does taper back in somewhat at the spokebed, I would definitely not classify it as narrow or pointy there - it's just not a blunt radius. In our shape optimization studies, we found that the balance of depth at 64mm and max width at ~30mm allowed us to better fine tune the trade off between wake recovery when the spoke bed is the trailing edge (wheel front half) and acceptable curvature for when the spoke bed is the leading edge (wheel back half).

One common misconception, I think, is that for some reason the spoke bed needs to be especially blunt or even match the tire radius. An optimized leading edge shape isn't necessarily a large blunt radius. And that's especially the case when that same shape is being co-optimized to be both a leading and trailing edge.

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Chris Yu
Applied Technology
Specialized Bicycle Components
@chrisyuinc

I'll bite and propose a test.....I would like to see the following bikes in the tunnel spec'ed as the highest end build the manufacturer specs them as.

• Specialized Venge ViAS
• Cervelo S5
• Felt AR
• Giant Propel Advanced SL
• Canyon Aeroad

Pick a person in the office that is most middle of the road and set the stack/reach/seat height to his/her measurements.


Invite a neutral representative who knows something about testing bikes in a wind tunnel. My vote is to throw Super Dave under the bus.


Test -15 to 15 at the fastest speed you are comfortable with. (You have pointed this out, but I will point it out further. The faster the speed the easier it will be to tease out small differences and as long as you go well below Mach 1 you should be able to scale numbers effectively :) )

Include 2 round water bottles and say what they are. i.e. size of the purist bottle you use

Anyone want to add/critique this?

(Edited to include water bottle comment)

???? How is SuperDave "neutral", especially when they would be testing a Felt?

(and just to clarify, I am not questioning SD's integrity...just pointing out that he would not be considered "neutral" anymore than Chris Yu would be. FWIW, I would trust the data from either of these guys. All evidence has proven for them both to be straight-shooters)

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Chicago Cubs - 2016 WORLD SERIES Champions!!!!

"If ever the time should come, when vain and aspiring men shall possess the highest seats in government, our country will stand in need of its experienced patriots to prevent its ruin." - Samuel Adams

ETA: Power13 beat me to it




Not saying SD would act in any way other than honorable...but he does have a rooting interest in the middle of that list of bikes. Right now, I don't. Just sayin' ;-)

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Carl Matson

Di2 on them all so cables don't obscure the results.

Maybe 'neutral' isn't the right word. He has the most to lose if the test isn't fair.

I have plenty of experience in tunnels, but no experience with bikes in tunnels. I know how to make small adjustments to cars to make big # differences. I have to assume that anyone who has a reasonable amount of time with bikes in a tunnel can make small changes that would effect the test greatly. Only another person that has that kind of experience can prevent that from happening.

Carl-
If you want to send a super secret prototype that may or may not be revealed on the 30th and show up I would say the more the merrier.

To anyone -> Propose someone who has experience in tunnels with bikes that isn't biased. Maybe Gerard...but that plane ticket would get expensive, and I'm willing to bet he has things going on.

To add....what are you more likely to believe/trust. A test signed off by one manufacturer's representative, or a test signed off by 2 manufacturer's representatives? Ideally you would have a rep from each company listed.....but I can't imagine everyone's schedules lining up.

I believe that the 'highest spec from each manufacturer' would be a Dura-Ace Di2 spec on all of them. Plus it would include Hed Jet Wheels on the Cervelo, and Zipp 404's on the Canyon, Giant and Felt.

The problem with a standardised test is that you get products designed to perform well in standardised tests.

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Developing aero, fit and other fun stuff at Red is Faster

no bike left behind?

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Carl Matson

I thought that was the whole goal of bike racing.....to leave others behind

:-)

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Developing aero, fit and other fun stuff at Red is Faster

Aren't you busy running for president?

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24 Hour World TT Champs-American record holder
Fat Bike Worlds - Race Director
Insta: chris.s.apex

Can I come? I'll bring a bike and a magazine tech editor or two.

-Dave

Maybe Damon could volunteer for this boondoggle.

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Pactimo brand ambassador, ask me about promo codes

Interesting description of the design. Would you care to comment on how Specialized prioritized pure aerodynamics against cross-wind stability? It seems to me that if the aerodynamic properties of the leading and trailing edges of the front wheel had similar drag you wouldn't have neutral handling in a cross wind, but it would probably be difficult to achieve across a range of yaw angles.

You'd be right to question my integrity, Felt signs my paycheck.
I'd love to be involved and I'm very much an #aeroiseverything guy. I'm using the data released to convince some of my teammates to ALWAYS wear our skinsuits, always wear shoe covers, always opt for the Synthe over the ProLight, Buy the AR1 instead of the F1, etc. I would think that someone like Jordan Rapp, who has prior ties to both Felt and Specialzied, is an aero adopter and is not entangled in promoting the 5 brands listed would be a better choice for the ST crowd.

In any case, I'll bring a bike and a tech editor or two if invited.

-SD

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https://www.kickstarter.com/...bike-for-the-new-era

If you get to come to the Win Tunnel for any competitive test I'll drive up! Please bring a BUCKET of Cheddar asparagus soup from Hartwig's and tell Scott there I said thanks!

-SD

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https://www.kickstarter.com/...bike-for-the-new-era

Chris

This might be a little off topic, but you always seem willing to share information and you asked what I might like to see. I also see commented on free speed in a recent article.

For road riding I would like to see information on the following
1) Frame finish , gloss vs matte
2) Bar tape , none vs some vs different types
3) Toe angle of the shift / brake levers In/Out
4) Gloves vs no gloves
5) Skewer angle
6) Water bottle size 20oz vs 28oz

Also a topic that we talked about a few years back , you probably don't remember. The side to side motion of the rider and bike effect on drag. At 50% of my FTP I'm very quite on my bike, as I approach my FTP I swing side to side more.

If you're driving up, pick me up along the way!

And Carl, if you could bring some Michael's Frozen Custard from Madison, that would be great :-)

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http://bikeblather.blogspot.com/

I think we really need to start factoring price into this. Set a budget and try and build the most aero bike under that budget. Use MSRP. I don't think it's fair to compare a $12.5k Venge ViAS to a $10k S5 when that extra $2k can be spent on a lot of other aero improvements.

Like what on the S5? It already comes with a very aero bar and a set of very fast wheels. What are you going to spend on?

About the only changes I'd make to that is TriRig Omega brakes, and trade in the Hed Jet 6+ wheels for "Black" models for even better braking. I'm at a loss for what to spend the rest of the $2K on...oh wait, maybe add a power meter? But, that's not going to make the "demand side" any lower...

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http://bikeblather.blogspot.com/

Cable.

Definitely out of the box thinking. Look out of place and ugly like discs. Brakes are approx. 3% of drag pie of bike vs. 90% body. It is worth it if you are an engineer getting payed by Specialized to sell bikes and market numbers. Brakes would add zero % to Cavendish in grand scheme of things. Aerobar more important.