Well...what's better, a surface being hit with "messy" air, or a slightly smaller surface being hit with "messy" air?

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http://bikeblather.blogspot.com/

Yeah...they need to graft the top half of Cervelo's "Zabriskie dummy" onto that thing :-)

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http://bikeblather.blogspot.com/

or c) an even smaller, smoother surface being hit with 'messy' air. I'm voting for 'C'.

Aren't the shapes of the spacer and the cleat the same in the areas of interest?...wait, I just checked and the 3 hole adapter is slightly triangular shape while the cleat edge is rectangular. OK, probably a bit of both.

In any case, whatever gains they saw are likely not because of moving the whole torso lower (assuming the seat height was adjusted down by the thickness of the adapters to account for the different pedal stacks).

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http://bikeblather.blogspot.com/

Hello stitchboy and All,

This set up might reduce the drag for Speedplays a bit, and you can run on them (a short distance):

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Cheers, Neal

+1 mph Faster

What set up is that? It looks like a crude version of shoes that the Project 96 team had. I got a look at some up at the Olympic Training Center a few years back - they had shoes that essentially faired in the pedal. Supposedly they had good aerodynamic properties.

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Christopher Kautz
Director of Technology, Product Development, and Education
GURU Sports, a division of Cannondale Sports Unlimited

That looks like them - seems like it would be a fast set up, never saw any data on them.

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Christopher Kautz
Director of Technology, Product Development, and Education
GURU Sports, a division of Cannondale Sports Unlimited

I think I have no choice but to convert to speedplays so that I may use a leg length shim. Shim systems are less than ideal for look/SPD because the shim needs to extend past the front of the cleat to allow the tip of the interface to still be wedged between two areas.

that'S what i did: remove insole, remove 3bolt plate, drill holes, put normal hex bolt nuts on the inside and fill the surrounding area where the original 3bolt steel plate used to be with foam (e.g. taken from a mouse pad). i also had to shim the speedplay cleat, but this is also useful to prevent the pedal from eating its way through the carbon sole. also, if your zero cleat have become too loose, put a thin plastic shim under the cleat and everything feels tight again

i dont know about the alloy nuts though... they are only 3 mm thin, and i dont think the weight savings justify the risks of stripping the threads in a sprint. also, i took the original hex bolt nuts that were in the speedplay 3bolt/4bolt adapter plates. didn't cost anything and is just as save as when using the adapter plate

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:::: Rocco's Studio 69 ::::

seriously, what is this?

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Want: 58cm Cervelo Soloist. PM me if you have one to sell

Vintage Cervelo: A Resource

I think ppl are thinking about this one wrong- maybe the speedplays are faster not becuase they get teh "Whole rider lower" but because the adapter plates themselves create drag- ie you wouldnt ride with a square block on top of your helmet- why ride with one on the bottom of each shoe?

sounds like the best plan would be:
a) wear shoe covers (why doesnt anyone but me wear shoe covers during IM? i can get mine on in about 30 nanoseconds)
b) use putty or something to create a smooth shape around the cleat on the bottom of the shoe

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~~~~~~~~~~~~~~~
-Cartels: Serotta, Zipp 2001, Guru, eh?
-"It was kinda long and then i got really tired"

Those are Carl Sundquist's Project 96 shoes from/for the Atlanta Olympics. He gave them to me and I was able to adapt the cleats to fit on/around a pair of Speedplay pedals so that I could use them (I also improved the elastomer locking system by adding some springs). I used them in one TT, but could never quite get the left shoe angled perfectly, as I ride quite toe-out, esp. on that side. I therefore gave them to Jens in hopes that he would do the field tests that I never got around to doing. He didn't either, though, so after about a year he gave them back to me, I eventually gave them to Greg, and Greg eventually gave them back to Don Lamson, who was happy to be reacquainted with some of his old handiwork. IOW, they are a well-traveled pair of shoes!

Isn't that basically the same thing I said?



That's basically what nealhe accomplished above. IIRC, he used some sort of moldable rubber compound....

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http://bikeblather.blogspot.com/

Of this I am not so sure.

Based on what? I'm thinking that IF they lowered the seat commensurately with the reduction in stack height, then any drag gains found are due to having less "stuff" exposed at the pedal and less seatpost sticking out of the frame (again, less "stuff" exposed).

However, if you can show me that raising or lowering a body in space by 4-7mm relative to the ground by itself (i.e. let's pretend it's "levitating" with no frame at all) can produce such reductions, I'm all ears :-)

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http://bikeblather.blogspot.com/

That they are... And I had every intention of testing them. But the crank in one of the interiors of the soles had me second guessing the value of testing vs destroying a piece of history.

FWIW, Don told me that they did in fact test them in the tunnel. And that if his memory serves they were slightly faster than std shoes with covers.

g

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greg
www.wattagetraining.com

Wind tunnel and field tests.

So...the "exposure" of no other part of the bike was changed in these tests and just the body was moved up and down?

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http://bikeblather.blogspot.com/

see your email

Is anyone from Speedplay on this thread/does anyone know someone who was involved in the test? First off, kudos to whoever designed and built the mannequin -- that's a hard job and the movement looks very lifelike. This is an engineering feat in itself, so very nice work.

Further more, it looks like the experiment and test protocal was set up very well. I must admit, I'm having a hard time understanding how the difference of the pedal system could be attributed to a 0.005 change in CdA. When pedaling, the cleat and pedals are in the wake of the toe of the shoe and only at the top of the pedal stroke does the pedal system present it's frontal area.

Back of the napkin calcs: So if a frontal area decrease of even two rectangles of 5mm x 50mm is possible by switching pedal systems, we have a frontal area decrease of 0.00025 m^2 or 0.045% of the frontal area of a 0.55 m^2 frontal area cyclist. Assuming Cd does not change as the pedal systems are seeing generally turbuent air at low speeds in the wake of the shoe (past flow separation of the shoe), this could decrease total system CdA by that same 0.045% or ~0.010 m^2 (of 0.24 m^2 system CdA).

Okay -- so in theory, if you held a shoe in tangential 30 mph flow, you could realize this frontal area decrease and thus the significant drag savings. The thing I don't know yet is if the pedal and cleat system actually sees this kind of a situation enough to garner this aerodynamic savings. Any flow visualization to share?

I ask these questions because I've studied this problem before and have seen the potential of the savings with shoes like the Project 96 shoes. I haven't ever been able to measure any dynamic test with this type of precision, and thus all of my shoe tests have ended without a definitive answer as to what was best (from wind tunnel data anyway).

Very interesting stuff,

Mark

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Mark Cote
MITAerobike
Specialized Bicycle Components

I agree...they did a good job...in fact, so good that (as I have commented elsewhere) I find the video of the pedaling lower torso strangely disturbing =:-0



Hmmm...I don't know...looking at the pedaling video, it appears to me that the pedal and cleats are exposed through the majority of the downstroke and it's only during the upstroke that they're "shielded" by the shoe/foot.



Hey...doesn't that point to a potential area of "shape improvement" for TT shoe designs?...hmmmm.....



Well...if the area is only presented 1/2 the time (as described above) that all falls into place, no?



The other thing we don't know is if the seat heights were adjusted to account for the differences in pedal/cleat stack heights (and thus keeping the orientations of the leg shapes the same to the air flow). Changing "leg extension" might have an effect, don't you think?



Thanks for your perspective! Good stuff.

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http://bikeblather.blogspot.com/

   
yeah but look at how far back and low the dummy is sitting :-) :-)

Is this at 0 yaw or a combination of angles? Seems like at 10 or 15 degrees it would be less because that air would then hit the frame.

Sure...but isn't proper seat height, even with a rotated forward position, generally indicated with the shoe/pedal interface basically parallel to the ground?

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http://bikeblather.blogspot.com/