I disagree, he may in fact have a decent position. note his weight and the amount of climbing in the 11miles(550).

we have a 6.5mi TT where going 26mph on 350w is good for me, on the flat that would be right at 30mph with same watts. climbing kills the w/m2 and crosses over to w/kg.

Better jersey for one.

You have spacers. Fix this problem and it'll help get your helmet in line with everything else.

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The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important.

-Albert J. Nock

When posting the photo I really noticed the parachute effect... err jersey.

Good ideas, once my longer tri is done I may experiment with removing some spacers and flipping the stem (it is "up" for now) -- I figure I could get lower with a small "comfort" sacrifice.

I thought maybe aerolab would give you wind...

But based on your speed I get ~3.5mph effective at bike level. Airports are usually 10m up I think, and <50% at bike level is normal.

Don't how much of a factor the hills were, but on a flat road you are looking at ~.34 CdA.

I'm 6'3" if that makes a difference.

It does... but not enough to justify that much drag.

The course doesn't look that hilly, but there must be something weird if the winner only averaged 24mph. I'd suggest doing field testing if you want to know your CdA.

 
Event - Lake Mills Triathlon - Sprint. Swim cancelled due to weather. TT start, probably started within the first 20 so very little drafting. Less than 200ft in elevation gain.

1) Average watts - 246w - NP 254w
2) Average speed in MPH - 22.5mph
3) Distance - 16 miles
4) Rider weight - 175lbs
5) Describe bike and wheels - Cannondale Slice 5, Zipp 404 front and back, Rudy Wingspan
6) Misc notes, to whine and make excuses for your lack of power and/or lack of aero - Windy day - 15mph with 25mph gusts. Based on the course design, never got the full effects of a tailwind

How do you field test CdA? I've always wondered.

Your position is not as bad as I was expecting. Obviously the jersey is costing you some time, and you can get lower and improve your head position. It may really just be the course though. Could be that the course was long as well. What does your computer say your speed/distance was? My TT this past Sunday was short by about .1-.2 miles. I've had a 40k that was actually closer to 41k before (at a state championship no less). So that's another possibility.

Either way, you can, and should, be getting more out of that power. I've got a couple pounds on you (I'm 195) and I'm 6'2 (so similar height), and I would expect to go closer to 28 mph on 330 watts.

Thanks again for the reply, I really do appreciate the feedback.

My computer came in pretty close (the course claims to be 11 miles but I had 10.93).

I will look at improving adjusting a bit and see if I can get some more data -- there are 5 more opportunities to do this TT and I can always do some experimental sessions with different setups. I'd be really excited for anything close to 26 mph or higher, here's to hoping!

Lake Mills Sprint Triathlon

1) 252 watts (PowerTap)
2) 23.8 mph
3) 16 miles
4) 154 lbs.
5) Trek Speed Concept 7, Reynolds 46, Aerojacket cover, Rudy Wingspan
6) 13th fastest bike split (out of 500). As eazyc10 mentioned the swim was cancelled because of poor conditions. I started a good 10 minutes after the first person and was shivering in line as I was wet from warmup, 54 degrees, with strong winds. The course was pretty congested and I got held up a few times with people three wide.

A Chung test is the best along with a ~zero wind day.

But if you want to find your CdA to a ballpark accuracy you just need to match up your performance to a model that uses the equations of motion. You need to input all the other variables like wind, weight, Crr, drivetrain losses, road grade, etc. Analytic Cycling has been around a long time. I see they have some here that might work, but I haven't tried them: http://www.cyclingpowerlab.com/CdAEstimation2.aspx

I was thinking that too. He is a former professional cyclist so I would think someone at that level would go faster but you never know what state a person's fitness is in.

   
I guess I will play. This is from my last sprint crystal river sprint, florida.



1) 182w (Quarq), 184bpm, 107rpm
2) 22.1
3) 15.14mi out and back, flat
4) 142lbs
5) 2011 Cervelo P2, Giro advantage 2, Sram Quarq, Flo 60/90, one bottle between bars
6) 10mph crosswind.
7)

You can do a bunch of rolldowns down a hill and do a ton of math. Or if you can find a route where you never have to hit the brakes and know your exact start and finish elevation and there's no wind, you can use Golden Cheetah's aerolab. It takes the power you put out, assumes you never hit the brakes, and produces a "virtual elevation" map. All you have to do is adjust your estimated and known parameters until the elevation profile matches the actual course profile.

I made an android app last year that automated the process (a voice told you when to start rolling, when to go back to the top of the hill, etc), but I found it was impossible to get the right combination of conditions. You needed good GPS reception (aka as much sky visible as possible) combined with no wind (aka as sheltered as possible). Those two requirements conflicted pretty badly. I had one or two good runs with it, but the rest were too windy or had too much car traffic.

Technically, you don't need to know your exact CDA anyway - you just need to know if a given configuration is faster or slower. You can do that fairly accurately with a stopwatch and a steepish well-sheltered hill.

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STAC Zero Trainer - Zero noise, zero tire contact, zero moving parts. Suffer in Silence starting fall 2016

Putah Creek 40K TT (6-5-13)

1) AP253W/NP255W
2) 25.9MPH (57:59)
3) 40K
4) 155 lbs.
5) Cervelo P2 w/ H3 front/DT Swiss w/ PT and wheel cover rear.
6) Whine: rear latex tube blew out 20 minutes before start. All I had was a butyl spare. It's a double out and back course (so there are three 180 degree turns) Undoubetdly this all cost me at least 5 minutes ;-).
7) Optional: a picture (or link to a picture) of you in your aero position. May be able to post one later.

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Mike Sparks


I have competed well, I have finished the race, I have kept the faith.

First TT of the year, sadly met with ho-hum results.

1.) 243
2.) 24.66
3.) 8 mi TT
4.) 152lbs
5.) Planet X Stealth, H3, Disc Cover
6.) First time on the TT bike since last September, new course (so one or two times I sat up and braked when I shouldn't have) and it was rainy. 522 ft gain

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My Blog - http://leegoocrap.blogspot.com

Hey st'ers,
So im fairly new to power, and, not that it really matters, but id like to know if my quarq is reading low. Ive raced with it two times and both time have manually calibrated it before the race.
Im 6'2" and weighed 173# for wildflower and 170# for Honu. Also attached pic from honu that I havnt been able to buy yet as im still in Maui.

1) wildflower olympic: very windy day, 2300 ft elevation according to strava
24.6 miles; 1:12:58 split (20.2mph avg); avg power including zeros 245w

2) Honu Ironman 70.3: pretty damn windy as well
55.66 miles, 2:35:26 split (21.5mph avg); avg power NOT including zeros 212w

Thanks for the help

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"If you can talk, go harder!"

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1) 228 AP
2) 26.0 mph (57:25)
3) Sattley 40k TT
4) 163lb, 5'11"
5) Shiv Tri, Flo 60 front, Hed Jet PT Disc rear, 23mm GP4000s w/latex, GA2 helmet, Bodypaint skinsuit, PI shoe covers
6) Can't make any excuses about the weather, absolutely perfect. '4900 ft elevation effects the watts though, sound like it would be ~250w sea level equivalent.
7) Same equipment and position:

AZ Cotton Classic TT - 6/9/13 - flat 40k - Hot (90+)

Average Watts: 270
Average Speed: 26.3 mph (56:46)
Rider weight: 88.5kg
Setup: Cervelo P2 (no bottle holders), Flo 90 front (GP4000s), Mavic Open Pro w/disc cover (Open Corsa CX), Michelin latex tubes, LG skinsuit, Giro A2 w/visor, Pearl Izumi shoe covers.

I really hope its not reading low.

??

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"If you can talk, go harder!"

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If I assume a Crr of .0045, CdA is .235. If Crr is .0040, CdA is .241.

Those are good numbers, but you might do better if you were a little lower in the front.

Thanks for taking the time to compute that, fun trivia to know.

That is about as low as I can comfortably get on 170 cranks. Have never tried any shorter.

Any way you could compute my estimated CdA based on my post above?