ghetto tape mod to create super extensions

this explains it all !!!!

😂 It probably provides no measurable benefit at all but still haha.

Any estimates on my CdA?

The surface was quite rough overall with quite some bumps in there as well.

Michelin Power Cup 25mm clinchers, Vittoria latex tubes (6.5Bar front, 6.2Bar rear)

It’s true that I would like to think the power is valid but I will check. The reason that I assumed that the power was valid is that I did a couple of short crit races early in the season on a road bike with a quark powermeter and had an np power of 308 and 312 for an hour. So those three datapoints give me confidence that the power during the tt could be a bit high but not a huge misreading.

I did an easy ride on the taxc and the difference between taxc and powermeter was 7 watts. Similar with earlier checks.

The good news is that even if the PM is off as long as it's consistently off you can still learn from it. Whether your true power:cda is 330:0.35 or 240:0.25 doesn't really change your finishing time.

I'd do some Chung method testing and try to lower your Cda with the various things listed in the thread. It's not the absolute CdA that matters here, just that you're finding ways to lower it.

<pink> While I think your result is great, suck it up and produce more watts </pink>

What kind of PM are you running ?

1) Average power = 288W, Normalized power = 293W
2) Average speed = 27.4MPH, 43.78km/h
3) Distance = 26.25Mi, 42km
4) Rider weight = 151lb, 68kg (winter weight yo, 2kg over weight still) Height = 5'7", 170cm
5) Describe bike and wheels = 2015 Trek Speed Concept, cheap Aliexpress 70mm Trispoke, Ron wheels Aeron X disc, Michelin Power Cup 25mm clinchers, Vittoria latex tubes (6.5Bar front, 6.2Bar rear), ghetto tape mod to create super extensions, Rotor Aldhu 54/38 155mm cranks, C-bear ceramic BB, KCNC oversized pulley system, KMC X11SL chain, SRAM PG1170 11-26 cassette. First time using my Nopinz Flow suit. Giro Aerohead. Aero socks.
6) Excuses: None, except for maybe having paced the opening lap a bit too slow. Very happy with the speed for the power I pushed.
7)





1st lap: 281W avg, 285W NP, 43.3kph, 19'31"
2nd lap: 293W avg, 295W NP, 44.4kph, 19'09"
3rd lap: 297W avg, 301W NP, 44.5kph, 19'03"

I'm a believer in High hands or Low hands, not "in-between" hands. Can you get more tilt on your bars so your hands are higher, and more in front of your face?

Take mywindsock CDA numbers with a pinch of salt.
If you are riding the same course for an example a Midweek TT every week you will see similar numbers weekly but ride another course and your numbers will be very different.
You can use to validate changes on the same course but your error margin would be around 0.005 at best.
I haven’t used it myself but have hear good things about Aerotune..

https://www.aerotune.com/

So I tried to do a little aero testing last Sunday (first try at it). Tried my full race setup, just switching from the M Aerohead to the L MET Drone and back to the Aerohead. As per the manual of Aerotune I used a 1km long stretch of road that's mostly smooth and flat, no traffic, to do out and back runs on a day with as little wind as possible. I tried to get up to speed as much as possible, maintaining the same power level throughout the segment but speed still increased partially throughout the segment so likely I need longer stretches of road to test on? The average speeds do resemble my race speeds of this season.

I created a Strava segment for it so I could check MyWindSock as well, which gave me:

Giro Aerohead:
First run out: 338W, 45.4kph, 0.219 CdA
First run back: 338W, 48.6kph, 0.184 CdA

So averages out to 0.2015?

Second run out: 346W, 46kph, 0.213 CdA
Second run back: 348W, 48.6kph, 0.182 CdA

So averages out to 0.1975? A bit counter intuitive to get a lower CdA value if I had to push 10W more for the same speed as on the first run back


MET Drone:
First run out: 346W, 46kph, 0.214 CdA
First run back: 339W, 49.3kph, 0.17 CdA

So averages out to 0.192?

Second run out: 343W, 46kph, 0.213 CdA
Second run back: 347W, 49.3kph, 0.18 CdA

So averages out to 0.1965?

Giro Aerohead:
First run out: 341W, 44.8kph, 0.207 CdA
First run back: 343W, 48.6kph, 0.187 CdA

So averages out to 0.197?

Second run out: 341W, 44.8kph, 0.202 CdA
Second run back: 337W, 49.3kph, 0.188 CdA

So averages out to 0.195? Again here a bit counter intuitive to have a very slightly higher CdA while I got a higher speed at a lower power than during the first run out?

To compare, MyWindSock calculated me to be at 0.195 for an entire 51 minute long TT where I only had to get out of the aerobars for a handful of seconds per 4km out of 40km, while using the Aerohead.

If I take the averages for the 2 runs for each "test", best case I have around 5.3W gain and worst case around 1.8W gain if you use a CdA change of 0.01 = 10W?

With Aerotune I find it a bit tricky, for the correct system weight (81.3kg) I tried to enter a few different CRRs. I ran at 6.4 bar F+R, Aerocoach quotes 0.00254 at 6.3 bar for the Michelin Power Cup Clinchers in 23mm which I use. BRR quotes 0.00288 for the 25mm version at 6.2 bar.

For a CRR of 0.0025, the power to maintain 45kph is calculated at 306W-294W-306W
For 0.0026 it is 307W-295W-297W
For 0.0028 it is 309W-297W-297W
For 0.003 it is 311W-299W-299W
For 0.004 (Marcag used this value to calculate the other TT I believe) it is 309W-297W-297W

I'll definitely need to test more and try out a longer stretch of road, but the CRR I estimate influences it a lot so I need to know/figure out what is realistic..

Got some pictures from the race

So I tried to do a little aero testing last Sunday (first try at it). Tried my full race setup, just switching from the M Aerohead to the L MET Drone and back to the Aerohead. As per the manual of Aerotune I used a 1km long stretch of road that's mostly smooth and flat, no traffic, to do out and back runs on a day with as little wind as possible. I tried to get up to speed as much as possible, maintaining the same power level throughout the segment but speed still increased partially throughout the segment so likely I need longer stretches of road to test on? The average speeds do resemble my race speeds of this season.

I created a Strava segment for it so I could check MyWindSock as well, which gave me:

Giro Aerohead:
First run out: 338W, 45.4kph, 0.219 CdA
First run back: 338W, 48.6kph, 0.184 CdA

So averages out to 0.2015?

Second run out: 346W, 46kph, 0.213 CdA
Second run back: 348W, 48.6kph, 0.182 CdA

So averages out to 0.1975? A bit counter intuitive to get a lower CdA value if I had to push 10W more for the same speed as on the first run back


MET Drone:
First run out: 346W, 46kph, 0.214 CdA
First run back: 339W, 49.3kph, 0.17 CdA

So averages out to 0.192?

Second run out: 343W, 46kph, 0.213 CdA
Second run back: 347W, 49.3kph, 0.18 CdA

So averages out to 0.1965?

Giro Aerohead:
First run out: 341W, 44.8kph, 0.207 CdA
First run back: 343W, 48.6kph, 0.187 CdA

So averages out to 0.197?

Second run out: 341W, 44.8kph, 0.202 CdA
Second run back: 337W, 49.3kph, 0.188 CdA

So averages out to 0.195? Again here a bit counter intuitive to have a very slightly higher CdA while I got a higher speed at a lower power than during the first run out?

To compare, MyWindSock calculated me to be at 0.195 for an entire 51 minute long TT where I only had to get out of the aerobars for a handful of seconds per 4km out of 40km, while using the Aerohead.

If I take the averages for the 2 runs for each "test", best case I have around 5.3W gain and worst case around 1.8W gain if you use a CdA change of 0.01 = 10W?

With Aerotune I find it a bit tricky, for the correct system weight (81.3kg) I tried to enter a few different CRRs. I ran at 6.4 bar F+R, Aerocoach quotes 0.00254 at 6.3 bar for the Michelin Power Cup Clinchers in 23mm which I use. BRR quotes 0.00288 for the 25mm version at 6.2 bar.

For a CRR of 0.0025, the power to maintain 45kph is calculated at 306W-294W-306W
For 0.0026 it is 307W-295W-297W
For 0.0028 it is 309W-297W-297W
For 0.003 it is 311W-299W-299W
For 0.004 (Marcag used this value to calculate the other TT I believe) it is 309W-297W-297W

I'll definitely need to test more and try out a longer stretch of road, but the CRR I estimate influences it a lot so I need to know/figure out what is realistic..

I raced here as well, Hanginon sent me a private message since I missed your topic.
These are my stats and some pictures I copied from the 'average power average speed' topic:


Did a 42km TT last Saturday, 13th out of 241 including some pros, elites and the current world hour record holder M45-49 (Filip Speybrouck) who only beat me by 1 second..


1) Average power = 288W, Normalized power = 293W
2) Average speed = 27.4MPH, 43.78km/h
3) Distance = 26.25Mi, 42km
4) Rider weight = 151lb, 68kg (winter weight yo, 2kg over weight still) Height = 5'7", 170cm
5) Describe bike and wheels = 2015 Trek Speed Concept, cheap Aliexpress 70mm Trispoke, Ron wheels Aeron X disc, Michelin Power Cup 25mm clinchers, Vittoria latex tubes (6.5Bar front, 6.2Bar rear), ghetto tape mod to create super extensions, Rotor Aldhu 54/38 155mm cranks, C-bear ceramic BB, KCNC oversized pulley system, KMC X11SL chain, SRAM PG1170 11-26 cassette. First time using my Nopinz Flow suit. Giro Aerohead. Aero socks.
6) Excuses: None, except for maybe having paced the opening lap a bit too slow. Very happy with the speed for the power I pushed.
7)





1st lap: 281W avg, 285W NP, 43.3kph, 19'31"
2nd lap: 293W avg, 295W NP, 44.4kph, 19'09"
3rd lap: 297W avg, 301W NP, 44.5kph, 19'03"


Paced the first lap too easy, but ah well..
I always try to build throughout the race instead of the 'smash and try to hold on' that a lot of people seem to use based on the times I can see.
This was basically double the length of the longest TT I've done and only my 4th ever TT so overall I'm happy with the result.