I know this has been discussed to death, but wanted to share my own results from yesterday - maybe others wants to chime in/share/critique:
**Test Protocol / Input: **
Rider & Setup Details:
Rider weight: 75 kgRider FTP: 340w Goal Watts for Test: 255wOverall setup all race-day: MET Drone helmet, trisuit, disc-wheel, Argon 18 E119, Vittoria G2.0 tubulars.
Test Course & Protocol:
5.2 km out and 5.2 km dead flat (By the Barcelona Airport, if anybody is curious)Total elevation for the test course is 5m. The course was ridden 4 times out and 4 times home. Loop 1 & 3 was ridden with a 1.5L empty water bottle in the front of the trisuit. Loop 2 & 4 without the bottle. The Outbound interval, was started after a 5 min break in Z1, pedaled up to 40 km/h at 255w, before starting the interval. The Homebound interval was started already up to speed and at 255w. This explains the slightly higher Avg HR on the home interval. See segment map belowWind: very low. Was stated as 5-6 km/h on local weather app, and mostly a side wind. Temperature: 22-25 degrees celciusOverall the whole test ride was 106 km and took 3h06m, which explains a slight HR creep upwards, over the test period.
Test Methodology Critics:
Slightly short course for the test.Only 4 test runs is not enough to show any real significance
Initial conclusions:
Fairly happy with the output around 43 km/h at 255w. Initially no benefits for me, using a plastic bottle down the front of the tri-suit. In both cases, the output was slower with the bottle. Happy to share more details to anybody interested. TIA
5.2 km out and 5.2 km dead flat (By the Barcelona Airport, if anybody is curious)Total elevation for the test course is 5m. The course was ridden 4 times out and 4 times home. Loop 1 & 3 was ridden with a 1.5L empty water bottle in the front of the trisuit. Loop 2 & 4 without the bottle. The Outbound interval, was started after a 5 min break in Z1, pedaled up to 40 km/h at 255w, before starting the interval. The Homebound interval was started already up to speed and at 255w. This explains the slightly higher Avg HR on the home interval. See segment map belowWind: very low. Was stated as 5-6 km/h on local weather app, and mostly a side wind. Temperature: 22-25 degrees celciusOverall the whole test ride was 106 km and took 3h06m, which explains a slight HR creep upwards, over the test period.
Test Methodology Critics:
Slightly short course for the test.Only 4 test runs is not enough to show any real significance
Initial conclusions:
Fairly happy with the output around 43 km/h at 255w. Initially no benefits for me, using a plastic bottle down the front of the tri-suit. In both cases, the output was slower with the bottle. Happy to share more details to anybody interested. TIA
Out: from Castelldefels towards the Airport (to Filipinas), then a small loop on the Taxi loop,
then Home: back to Filipinas and on C-31 to Castelldefels (as far as you can go on C-31, before it become Autopista)
Do you see the map I posted in the original post?
T
5.2 km out and 5.2 km dead flat (By the Barcelona Airport, if anybody is curious)
Did you ride on the highway, or is there something I am missing? I am always on the lookout for aero test locations…
I would be be careful to draw conclusions that a bottle is slower for you. You went faster for every try, if you would have done another one with bottle it might have been faster again.
Something changed throughout your test, maybe wind and temperature changed enough to make a difference!
For a 5.2km test at aprox 43km/h (less than 8 minutes…), the accuracy of the measure I guess is not good enough to extract any conclusions. Usually the aero benefits for a 180km TT are around 3 to 5 minutes. So for your test I guess you would see a difference in between 3 to 6 seconds. I don’t know the equipment used to measure the distance and the time, but if GPS and your eye-hand neuromotor coordination were to be used, the test I would say is not good. But it is a good start…
Fair points! I would say the total test track is 10.4 km and close to 18-19 min in total, out and home. I find it hard to see how adding much more distance to the test will change the outcome avg velocity. It really is hard to find any segments with undisturbed possibilities of staying in aero, and steady-state watts for much longer amounts of time.
I saw the Sanders Aero testing, and the course they use is much shorter, I believe
The data is taken from a Garmin 540 unit and intervals are started and stopped going under walking bridges.
Thanks for chiming in!
For a 5.2km test at aprox 43km/h (less than 8 minutes…), the accuracy of the measure I guess is not good enough to extract any conclusions. Usually the aero benefits for a 180km TT are around 3 to 5 minutes. So for your test I guess you would see a difference in between 3 to 6 seconds. I don’t know the equipment used to measure the distance and the time, but if GPS and your eye-hand neuromotor coordination were to be used, the test I would say is not good. But it is a good start…
I think there might be some issues with the protocol
The C-31 has traffic at speeds around 100km/h, and even though you’re riding in the shoulder it’s not very wide thus it can potentially interfere with the results
You might want to try A/B/B/A runs instead of A/B/A/B
Furthermore, you have to brake to make the turn at both ends so you can’t easily use the virtual elevation method in goldencheetah (as far as i know)
If you could find a shorter circuit that you can ride “indefinitely” without braking (all right turns or roundabout maybe?) doing several laps with no traffic, I think it’d be better
.
1). Testing was done early saturday, so not really any traffic and cars tend to pass in the left lane. Either way, if the cars interfere, its both WITH and WITHOUT the bottle. So not really giving any difference in results.
The Runs are A/B then B/A.
As in:
Course Out: CDF (the surf shop) to Rotunda Filipinas exit
Course Home: Airport (actually starting the lap at El Row or the firecracker factory) then back to CDF (a bit further than the old Riviera)
See the map!
As per pt. 2 - there are no turns on the course out and home. Dead straight.
Yes a round course would be optimal, but not even on Montmelo you can be 100% in Aero all the way round, at least not at 255w avg
Thanks again
Hi Mulen,
I think there might be some issues with the protocol
The C-31 has traffic at speeds around 100km/h, and even though you’re riding in the shoulder it’s not very wide thus it can potentially interfere with the results
You might want to try A/B/B/A runs instead of A/B/A/B
Furthermore, you have to brake to make the turn at both ends so you can’t easily use the virtual elevation method in goldencheetah (as far as i know)
If you could find a shorter circuit that you can ride “indefinitely” without braking (all right turns or roundabout maybe?) doing several laps with no traffic, I think it’d be better
I think there might be some issues with the protocol
The C-31 has traffic at speeds around 100km/h, and even though you’re riding in the shoulder it’s not very wide thus it can potentially interfere with the results
You might want to try A/B/B/A runs instead of A/B/A/B
Furthermore, you have to brake to make the turn at both ends so you can’t easily use the virtual elevation method in goldencheetah (as far as i know)
If you could find a shorter circuit that you can ride “indefinitely” without braking (all right turns or roundabout maybe?) doing several laps with no traffic, I think it’d be better
actually as has been pointed out in the virtual elevation thread, the braking can be used for confirmation and can be cut out of the data, the bigger problem for virtual elevation is traffic and thus variable wind impact. If a person wants to do this sort of minor CdA type evaluation it is best in a sheltered area with an elevation change, and little or very consistent light wind. Read the article done by Dr. R Chung who is often on this forum and who invented the virtual elevation methods or the Chung method. or this article by Josh at Silca: https://silca.cc/blogs/silca/chunging-with-robert-chung. If you search R Chung you should find an outline Dr. Chung wrote on the method.
The protocol used is flawed on numerous levels and there are people far more expert than I who can point them out.
