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Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands"
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Speedplay has done just completed wind-tunnel testing of clipless pedals. It looks like they used a pretty repeatable protocal. They claim and look like they beat out Look and Shimano pedals. Something to bear in mind is that the 3 hole mounted Speedplay pedals performed marginally better than the other 2 pedals, .242 to .243. However the big time savings came from Speedplay pedals mounted on 4 hole shoes, with drag at .237. My problem with this data is the 4 hole shoes. Does any manufacturer even make 4 bolt shoes? Every shoe I have seen for the last couple years have been 3 hole. Still a very interesting test and I am always glad to see companies put out aero data, flawed or not. Then we can at least discuss it on this forum and get some much smarter people than me to dissect this data and make sense of it all.

http://www.speedplay.com/...=home.slipperypedals

As an aside, I use Speedplay pedals on my road bike as I simply like to click in or out without thinking. I do race on Time RXS Ulteams for my tribike because they are sweet and I can actually trot in the cleats without slipping on my butt in T1 if I am lazy and don't want to do a running mount, or can't, because I am not allowed (many races).





People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf. George Orwell
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [stitchboy] [ In reply to ]
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Blah, Blah-do they provide a fire extinguisher to put out those hot spots?Didn't think so. Next?
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [stitchboy] [ In reply to ]
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Lake is the only stock shoe maker that does four-hole shoes standard. But Rocket7 and every other custom maker will do four hole. Some of the shoes with adapter plates (Carnac?) may have four bolt adapter plates.

"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Rappstar] [ In reply to ]
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Thanks Rappstar, I did not know that Lake made four-hole shoes. I guess I am always looking at other brands like Shimano, Sidi, Specialized, etc.. I may need to do some shoe shopping now! No way can I justify a pair of Rocket 7's as much as I would like to. Just curious as to what shoe and clipless system you use?





People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf. George Orwell
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [stitchboy] [ In reply to ]
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it is absolutely no problem to drill 4 holes into a carbon sole and mount the cleats directly. i have done that with DMT RSX Ultimax and Bontrager Hilo shoes wothout any problems. Just make sure you buy bolts with the correct length.

i love speedplay pedals, both on- and offroad, but the huge time savings seem to me like the zipp crank time savings BS...

:::: Rocco's Studio 69 ::::
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Rocco69] [ In reply to ]
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Are the time savings bogus? I would say I don't really know. It appears Speedplay really tried to isolate the test with as few variables as possible. I think the aero results may fall into the same problem as the Zipp crank. This seems to be a very difficult area to assess as these parts are rotating while being connected to someones legs, which have all kinds of different shapes and efficiency levels. Also some people pedal with toes down, etc..
I would still buy the Zipp crank if it cost about a $1000 dollars less and weighed about 100 grams less. For now I will stick with my "slow" K-Force light (Bonktown $349) and Time pedals.





People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf. George Orwell
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [stitchboy] [ In reply to ]
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No mention in their article of sample size (did they do replicate runs? if so, how many?), of whether they used more than one set of shoes of each type (thereby accounting for differences between shoes) or of the statistical significance of the differences they found. 2/10

Vanity Blog http://triathlonfoolishness.blogspot.com/
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [stitchboy] [ In reply to ]
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In Reply To:
Thanks Rappstar, I did not know that Lake made four-hole shoes. I guess I am always looking at other brands like Shimano, Sidi, Specialized, etc.. I may need to do some shoe shopping now! No way can I justify a pair of Rocket 7's as much as I would like to. Just curious as to what shoe and clipless system you use?
Specialized with speedplay. Lake shoes are very nice, though. I rode Lake's for a while and really liked them as well. I'd not hesitate for a moment to use them again.

"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [stitchboy] [ In reply to ]
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i am curious, is the speedplay cleat fundamentally differently shaped when attached to a 4-hole shoe, vs. a 3-hole shoe? anyone know?

i am a little skeptical of these wind tunnel results. because while speedplay pedals are indeed quite small, the speedplay cleat is really enormous, so it seems to me that any so-called drag savings would basically be zero, or maybe 1-2 sec over a 40km TT. anyone have any thoughts? or am i missing something?





Where would you want to swim ?
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [stitchboy] [ In reply to ]
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Anyone know if the Speedplay pedals and the "other" (why not name 'em?) pedal systems have the same height, and whether any difference in height affected the drag of the mannequin's legs?

Just curious.

----------------------------------
"Go yell at an M&M"
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Rappstar] [ In reply to ]
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If (and big if) someone had some NOS on a few year old Time or Carnac shoes with the TBT sole...they also had four hole. This would give a much lower stack height....

----------------------------------------------------------

What if the Hokey Pokey is what it is all about?
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [GregX] [ In reply to ]
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In Reply To:
i am curious, is the speedplay cleat fundamentally differently shaped when attached to a 4-hole shoe, vs. a 3-hole shoe? anyone know?

i am a little skeptical of these wind tunnel results. because while speedplay pedals are indeed quite small, the speedplay cleat is really enormous, so it seems to me that any so-called drag savings would basically be zero, or maybe 1-2 sec over a 40km TT. anyone have any thoughts? or am i missing something?

my understanding is that with a 4 hole shoe, the cleat mounts directly to the shoe, with a 3 hole shoe, the speedplay cleat needs an adapter which adds about 4-7mm? of height.

http://www.lakecycling.com/...-speedplay-p-69.html



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

Vintage Cervelo: A Resource
Last edited by: jeremyb: Aug 5, 09 12:40
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Rocco69] [ In reply to ]
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In Reply To:
it is absolutely no problem to drill 4 holes into a carbon sole and mount the cleats directly. i have done that with DMT RSX Ultimax and Bontrager Hilo shoes wothout any problems. Just make sure you buy bolts with the correct length.
Into what do the bolts then thread...do you put a T-nut under the footbed or something?
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Andrew Coggan] [ In reply to ]
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Looking at the test it seems fairly clear that the Cd difference is attributable to the 4mm height difference of the mannequin since that is the only real difference between the 3 hole and 4 hole mountings. Their own test suggests that since there was no significant difference between the 3 hole speedplays and the brand X pedals. The 33 second number is also inflated since the percentage difference wouldn't be that high had they included the whole mannequin and included rolling resistance. Note that the mannequin is only using 54 watts at 30MPH. I'd also like to see margin of error on the tests.

That said, I do believe that there would be a small but measurable aero advantage to dropping 4mm in overall height. Anyone have any more info on modifying 3 hole shoes? Would the footbed curve be compatible?
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [ryancampbell] [ In reply to ]
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In Reply To:
Note that the mannequin is only using 54 watts at 30MPH.
Producing, actually.
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Andrew Coggan] [ In reply to ]
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In Reply To:
Producing, actually.[/reply]Ah, OK, but the point still remains that much of the overall Cd was omitted by loping off the top half of the bike and rider and thus the denominator in the Cd comparison would have been larger. I'm not sure what equation they used to get the 33 seconds/hour and if they took this into account.
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [ryancampbell] [ In reply to ]
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In Reply To:
the point still remains that much of the overall Cd was omitted by loping off the top half of the bike and rider and thus the denominator in the Cd comparison would have been larger.

Would it, at least necessarily? There are a lot of people out there with CdAs of <0.25 m^2...
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [ryancampbell] [ In reply to ]
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In Reply To:
In Reply To:
Producing, actually.
Ah, OK, but the point still remains that much of the overall Cd was omitted by loping off the top half of the bike and rider and thus the denominator in the Cd comparison would have been larger. I'm not sure what equation they used to get the 33 seconds/hour and if they took this into account.[/reply]
Ummm...doesn't just the absolute value of the reduction (i.e. .005 m^2 of CdA) matter?

That said what exactly does a "time savings of 33s per hour" mean? I don't quite understand that...does it allow you to reach relativistic speeds or something? ;-)

Using the ROT, that .005 m^2 reduction would result in a time savings of ~0.5s per km, or about 20s over 40K.

http://bikeblather.blogspot.com/
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Andrew Coggan] [ In reply to ]
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Hmmm, good point. Considering the reduced frontal area of the test setup (no shoulders, handlebars, back), that lower body shape must have a terrible Cd compared to a real cyclist to arrive at that CdA. That would also exacerbate the effect of poking that shape up 4mm into the wind.

Anyway, I do believe that there must be some postitive aero effect of lowering a cyclist on a bike, but I'm very suspicious of SpeedPlay's rational for removing parts of the cyclist and bike to remove "extraneous hardware". I certainly don't consider my heart, lungs, and head to be "extranous" :-) I'd suspect that the numbers just turned out better this way.
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [ryancampbell] [ In reply to ]
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If you use the 3 hole and adapter you still have a lower stack height then the look pedals. If your theory were true then there should be an even change between look, speedplay w/ adapter, and speedplay 4 bolt but there isn't. Also, if you take a box's frontal area, and the lower the box, its frontal area is the same. The only problem would be if they didn't adjust the stem to match the new stack height which could alter the aerodynamics?

*edit there is no stem, they would need to adjust the saddle height to match the stack height otherwise the data is erroneous. Did they do that?

Ride Scoozy Electric Bicycles
http://www.RideScoozy.com
Last edited by: msuguy512: Aug 5, 09 15:21
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [ryancampbell] [ In reply to ]
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In Reply To:
Hmmm, good point. Considering the reduced frontal area of the test setup (no shoulders, handlebars, back), that lower body shape must have a terrible Cd compared to a real cyclist to arrive at that CdA. That would also exacerbate the effect of poking that shape up 4mm into the wind.

Don't forget the wheels used on that setup...not exactly a deep front and a disc ;-)

I'd expect a "full" cyclist on that road setup to have a total CdA closer to .350 m^2 than .250 m^2. The CdA that AC was referring to was a "full aero" TT-type CdA.


In Reply To:

Anyway, I do believe that there must be some postitive aero effect of lowering a cyclist on a bike, but I'm very suspicious of SpeedPlay's rational for removing parts of the cyclist and bike to remove "extraneous hardware". I certainly don't consider my heart, lungs, and head to be "extranous" :-) I'd suspect that the numbers just turned out better this way.

I don't think it's so much about lowering the body relative to the bike or pedals, but more about removing the surface area of the front of the spacer out of the air stream.

It's really about reducing the "A" part of the CdA.

http://bikeblather.blogspot.com/
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Tom A.] [ In reply to ]
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In Reply To:

I don't think it's so much about lowering the body relative to the bike or pedals, but more about removing the surface area of the front of the spacer out of the air stream. It's really about reducing the "A" part of the CdA.

i concur

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

Vintage Cervelo: A Resource
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Andrew Coggan] [ In reply to ]
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I did it to a pair of shoes once. they were Nikes which tend to already be pretty light. I removed the insole and pried up the card board footbed. this allowed me to remove the steel plate that the shimano two hole and look 3 hole cleats bolt to. I drilled 4 holes in carbon sole then used a small triangular file to file the hole into hexagons. I put aluminum mushroom hex head nuts into the holes, put the insole back in and used aluminum screws to put he speedplay cleat on. I had to shim the cleat with some plastic pieces to match the curve of the sole, but between removing the steel plate, eliminating the adapter, and using aluminum hardware it saved quite a bit of weight and lovered me a few mm.

Styrrell

Styrrell
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Tom A.] [ In reply to ]
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In Reply To:
In Reply To:
Hmmm, good point. Considering the reduced frontal area of the test setup (no shoulders, handlebars, back), that lower body shape must have a terrible Cd compared to a real cyclist to arrive at that CdA. That would also exacerbate the effect of poking that shape up 4mm into the wind.

Don't forget the wheels used on that setup...not exactly a deep front and a disc ;-)

I'd expect a "full" cyclist on that road setup to have a total CdA closer to .350 m^2 than .250 m^2. The CdA that AC was referring to was a "full aero" TT-type CdA.


but doesn't a CdA of .234 seem crazy-high for half of a body??? That cut-off torso must have some horrible drag (and is quite freaky-looking)


In Reply To:

Anyway, I do believe that there must be some postitive aero effect of lowering a cyclist on a bike, but I'm very suspicious of SpeedPlay's rational for removing parts of the cyclist and bike to remove "extraneous hardware". I certainly don't consider my heart, lungs, and head to be "extranous" :-) I'd suspect that the numbers just turned out better this way.

I don't think it's so much about lowering the body relative to the bike or pedals, but more about removing the surface area of the front of the spacer out of the air stream.

It's really about reducing the "A" part of the CdA.
are you sure about that?? I remember looking at the flow-sim that Zebragonzo had done, and it sure looked like the bottom of the feet was really messy.
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [stitchboy] [ In reply to ]
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my very quick thoughts are that 'pedals probably matter', which is why I use a different pedal/shoe combo for my road bike and TT bike. I don't think they matter as much as is being claimed here, and I'd be pretty curious to see the repeatability of their results, and some more details on the protocol.

I think there are better options out there than Speedplays when it comes to aerodynamics.

I kind of amazed that a pedal company can come up with a pedaling dummy, and bicycle companies can't/haven't? It seems that this would be the holy grail of wind tunnel testing frames/equipment.
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [roady] [ In reply to ]
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In Reply To:
In Reply To:
In Reply To:
Hmmm, good point. Considering the reduced frontal area of the test setup (no shoulders, handlebars, back), that lower body shape must have a terrible Cd compared to a real cyclist to arrive at that CdA. That would also exacerbate the effect of poking that shape up 4mm into the wind.

Don't forget the wheels used on that setup...not exactly a deep front and a disc ;-)

I'd expect a "full" cyclist on that road setup to have a total CdA closer to .350 m^2 than .250 m^2. The CdA that AC was referring to was a "full aero" TT-type CdA.


but doesn't a CdA of .234 seem crazy-high for half of a body??? That cut-off torso must have some horrible drag (and is quite freaky-looking)


In Reply To:

Anyway, I do believe that there must be some postitive aero effect of lowering a cyclist on a bike, but I'm very suspicious of SpeedPlay's rational for removing parts of the cyclist and bike to remove "extraneous hardware". I certainly don't consider my heart, lungs, and head to be "extranous" :-) I'd suspect that the numbers just turned out better this way.

I don't think it's so much about lowering the body relative to the bike or pedals, but more about removing the surface area of the front of the spacer out of the air stream.

It's really about reducing the "A" part of the CdA.
are you sure about that?? I remember looking at the flow-sim that Zebragonzo had done, and it sure looked like the bottom of the feet was really messy.

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

http://bikeblather.blogspot.com/
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [roady] [ In reply to ]
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In Reply To:
I kind of amazed that a pedal company can come up with a pedaling dummy, and bicycle companies can't/haven't? It seems that this would be the holy grail of wind tunnel testing frames/equipment.

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

http://bikeblather.blogspot.com/
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Tom A.] [ In reply to ]
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In Reply To:
In Reply To:
In Reply To:
In Reply To:
Hmmm, good point. Considering the reduced frontal area of the test setup (no shoulders, handlebars, back), that lower body shape must have a terrible Cd compared to a real cyclist to arrive at that CdA. That would also exacerbate the effect of poking that shape up 4mm into the wind.

Don't forget the wheels used on that setup...not exactly a deep front and a disc ;-)

I'd expect a "full" cyclist on that road setup to have a total CdA closer to .350 m^2 than .250 m^2. The CdA that AC was referring to was a "full aero" TT-type CdA.


but doesn't a CdA of .234 seem crazy-high for half of a body??? That cut-off torso must have some horrible drag (and is quite freaky-looking)


In Reply To:

Anyway, I do believe that there must be some postitive aero effect of lowering a cyclist on a bike, but I'm very suspicious of SpeedPlay's rational for removing parts of the cyclist and bike to remove "extraneous hardware". I certainly don't consider my heart, lungs, and head to be "extranous" :-) I'd suspect that the numbers just turned out better this way.

I don't think it's so much about lowering the body relative to the bike or pedals, but more about removing the surface area of the front of the spacer out of the air stream.

It's really about reducing the "A" part of the CdA.
are you sure about that?? I remember looking at the flow-sim that Zebragonzo had done, and it sure looked like the bottom of the feet was really messy.

Well...what's better, a surface being hit with "messy" air, or a slightly smaller surface being hit with "messy" air?
or c) an even smaller, smoother surface being hit with 'messy' air. I'm voting for 'C'.
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [roady] [ In reply to ]
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In Reply To:
In Reply To:
Well...what's better, a surface being hit with "messy" air, or a slightly smaller surface being hit with "messy" air?
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).

http://bikeblather.blogspot.com/
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [stitchboy] [ In reply to ]
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Hello stitchboy and All,

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



Cheers, Neal

+1 mph Faster
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [nealhe] [ In reply to ]
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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.


Christopher Kautz
Director of Technology, Product Development, and Education
GURU Sports, a division of Cannondale Sports Unlimited
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [ckautz] [ In reply to ]
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In Reply To:
What set up is that? It looks like a crude version of shoes that the Project 96 team had.

You mean these?

http://wattagetraining.com/boatShoes.jpg



g


greg
www.wattagetraining.com
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [gregclimbs] [ In reply to ]
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That looks like them - seems like it would be a fast set up, never saw any data on them.


Christopher Kautz
Director of Technology, Product Development, and Education
GURU Sports, a division of Cannondale Sports Unlimited
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Tom A.] [ In reply to ]
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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.
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [styrrell] [ In reply to ]
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In Reply To:
I did it to a pair of shoes once. they were Nikes which tend to already be pretty light. I removed the insole and pried up the card board footbed. this allowed me to remove the steel plate that the shimano two hole and look 3 hole cleats bolt to. I drilled 4 holes in carbon sole then used a small triangular file to file the hole into hexagons. I put aluminum mushroom hex head nuts into the holes, put the insole back in and used aluminum screws to put he speedplay cleat on. I had to shim the cleat with some plastic pieces to match the curve of the sole, but between removing the steel plate, eliminating the adapter, and using aluminum hardware it saved quite a bit of weight and lovered me a few mm.

Styrrell

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

:::: Rocco's Studio 69 ::::
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [nealhe] [ In reply to ]
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In Reply To:
Hello stitchboy and All,

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

seriously, what is this?

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

Vintage Cervelo: A Resource
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Tom A.] [ In reply to ]
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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

~~~~~~~~~~~~~~~
-Cartels: Serotta, Zipp 2001, Guru, eh?
-"It was kinda long and then i got really tired"
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [ckautz] [ In reply to ]
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In Reply To:
That looks like them - seems like it would be a fast set up, never saw any data on them.

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!
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [clyde_s_dale] [ In reply to ]
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In Reply To:
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?

Isn't that basically the same thing I said?


In Reply To:
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

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

http://bikeblather.blogspot.com/
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Tom A.] [ In reply to ]
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In Reply To:
whatever gains they saw are likely not because of moving the whole torso lower

Of this I am not so sure.
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Andrew Coggan] [ In reply to ]
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In Reply To:
In Reply To:
whatever gains they saw are likely not because of moving the whole torso lower

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 :-)

http://bikeblather.blogspot.com/
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Andrew Coggan] [ In reply to ]
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<long travelling story> ....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!

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


greg
www.wattagetraining.com
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Tom A.] [ In reply to ]
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Based on what?

Wind tunnel and field tests.
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Andrew Coggan] [ In reply to ]
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Based on what?

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?

http://bikeblather.blogspot.com/
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Tom A.] [ In reply to ]
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Based on what?

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?
see your email
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Tom A.] [ In reply to ]
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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

--
Mark Cote
MITAerobike
Specialized Bicycle Components
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [MITaerobike] [ In reply to ]
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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.

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


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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.

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.


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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),...

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


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...this could decrease total system CdA by that same 0.045% or ~0.010 m^2 (of 0.24 m^2 system CdA).

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


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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?

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?


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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).

Thanks for your perspective! Good stuff.

http://bikeblather.blogspot.com/
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Tom A.] [ In reply to ]
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Tom. A ... 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.
yeah but look at how far back and low the dummy is sitting :-) :-)
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Tom A.] [ In reply to ]
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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.
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [rmur] [ In reply to ]
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Tom. A ... 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.
yeah but look at how far back and low the dummy is sitting :-) :-)

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?

http://bikeblather.blogspot.com/
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [rmur] [ In reply to ]
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Tom. A ... 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.
yeah but look at how far back and low the dummy is sitting :-) :-)

In fact, check out this pic of a fairly forward position...there's still apparently a fair bit of pedal exposed all around the stroke, no? ;-) (BTW, those are Time RXS pedals)



http://bikeblather.blogspot.com/
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Tom A.] [ In reply to ]
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check out this pic of a fairly forward position...there's still apparently a fair bit of pedal exposed all around the stroke, no? ;-) (BTW, those are Time RXS pedals)


A lot of rear derailleur, too (albeit partially due to the camera angle).
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Andrew Coggan] [ In reply to ]
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check out this pic of a fairly forward position...there's still apparently a fair bit of pedal exposed all around the stroke, no? ;-) (BTW, those are Time RXS pedals)

A lot of rear derailleur, too (albeit partially due to the camera angle).

But...it's a nice and SMOOTH old Shimano 600 model...no gaps or sharp angles on that thing :-)

http://bikeblather.blogspot.com/
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Tom A.] [ In reply to ]
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well I suppose - depends on a lot of things like cleat postion too ... but I do think the dummy is more or less 'sitting up' vs. a typical TT position.

Anyhow good marketing by Speedplay to generate lots of visits to their site! I suspect the real savings are mucho lesso ... no booties for example. IMHO there ARE cheaper ways!
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [nealhe] [ In reply to ]
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Strikes me that this is the key takeaway from all this- not that we shoudl all somehow mount speedplays with no adaptor plates to our shoes (very hard to do) but instead, we should smooth out our shoees sot he cleats dont stick out.

What did you use on this pic to aero-out the cleats?

Clyde

~~~~~~~~~~~~~~~
-Cartels: Serotta, Zipp 2001, Guru, eh?
-"It was kinda long and then i got really tired"
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [MITaerobike] [ In reply to ]
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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?
Is that a paper or cloth napkin? .045% of .24 is .0001, not .01.
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [tigermilk] [ In reply to ]
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Yup! Sorry missed a couple of decimal places there! Sorry! Yeah, 0.0001 or 0.0002 m^2 seems more realistic by my estimation and there's no way you can measure that in a wind tunnel.

So either the shape change has a huge effect on the drag or the wind tunnel measurement precision to take this type of a measurement was a bit off.

Thanks for catching my mistake, tiger.

Mark

--
Mark Cote
MITAerobike
Specialized Bicycle Components
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [MITaerobike] [ In reply to ]
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0.0001 or 0.0002 m^2 seems more realistic by my estimation and there's no way you can measure that in a wind tunnel.

What's the precision of various wind tunnels? Is this generally advertised?
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [RChung] [ In reply to ]
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0.0001 or 0.0002 m^2 seems more realistic by my estimation and there's no way you can measure that in a wind tunnel.

What's the precision of various wind tunnels? Is this generally advertised?
Texas A&M tunnel - http://lswt.tamu.edu/info.htm

.01 lb resolution, so likely no joy. CdA of .0001 at 30 mph is what, .01 N on it's own. So on the order of .002x lbf. Could of course have some better force balances, but still, .01 N is no way 33 seconds.
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [tigermilk] [ In reply to ]
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0.0001 or 0.0002 m^2 seems more realistic by my estimation and there's no way you can measure that in a wind tunnel.

What's the precision of various wind tunnels? Is this generally advertised?
Texas A&M tunnel - http://lswt.tamu.edu/info.htm

.01 lb resolution, so likely no joy. CdA of .0001 at 30 mph is what, .01 N on it's own. So on the order of .002x lbf. Could of course have some better force balances, but still, .01 N is no way 33 seconds.

Thanks. I agree, that seems inconsistent with 33 seconds.
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [clyde_s_dale] [ In reply to ]
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Strikes me that this is the key takeaway from all this- not that we shoudl all somehow mount speedplays with no adaptor plates to our shoes (very hard to do) but instead, we should smooth out our shoees sot he cleats dont stick out.

What did you use on this pic to aero-out the cleats?

Clyde
You mean like these shoes on which I'll be doing some field testing in a velodrome:



See here:
http://www.bont.com/...pages/bontcrono.html

_________________________________________________________________________________
Training Plans -- Power Meter Hire -- SRM Sales Australia -- cyclecoach.com -- My Blog -- Sydney Turbo Studio
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [Alex Simmons] [ In reply to ]
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Strikes me that this is the key takeaway from all this- not that we shoudl all somehow mount speedplays with no adaptor plates to our shoes (very hard to do) but instead, we should smooth out our shoees sot he cleats dont stick out.

What did you use on this pic to aero-out the cleats?

Clyde
You mean like these shoes on which I'll be doing some field testing in a velodrome:



See here:
http://www.bont.com/...pages/bontcrono.html


They look cool, but this claim "After all, your feet are the fastest moving part of a bike." I would say the spokes or tires are moving faster.

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

Vintage Cervelo: A Resource
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Re: Speedplay claims huge wind drag reduction... 33 seconds per hour over "leading brands" [stitchboy] [ In reply to ]
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Digging up an old thread here, which I found searching for info on Speedplay's claimed aero gain over other pedals when used with 4 hole shoes.

As it has been a few years now, I was wondering if anyone has tried to replicate Speedplay's results with their own field testing, and if so whether they were able to measure any difference?
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