This is a great way to determine an optimal TT position without the heavy cost of a wind tunnel. Wheels, helmets and power meters will be supplied in order to provide the highest level of feedback and equipment selection.
http://www.source-e.net/public-content/TT-Test-Tune
Note you do not need a certification to ride on the velodrome for this clinic, all are welcome and all proceeds go back to support the Alkek velodrome.
Now that sounds like fun! I have to ask, though: to people get a rain-check if there is too much wind that day? 
(A bit more seriously: if possible, it might be worth putting a recording anemometer in the middle of the infield, so that people have at least some idea just how hard and from what direction the wind was during their runs. That may prevent them from putting too much stock in data that they perhaps shouldn’t, and making inappropriate - and perhaps expensive - decisions based on it.)
No rain check (40% threat of rain at all times at Alkek, that’s Houston for you!). With this being a fundraiser for Alkek, if it rains…well the track needs funds to patch holes. We’ll be there either way.
Great point on the anemometer we have one to set up that should help us interpret the data even more accurately.
If you could synchronize timers on the device recording wind speed and direction and the power meters
then you could normalize everything =)
Now that sounds like fun! I have to ask,
though: to people get a rain-check if there is too much wind that day?
(A bit more seriously: if possible, it might be worth putting a recording anemometer in the middle of the infield, so that people have at least some idea just how hard and from what direction the wind was during their runs. That may prevent them from putting too much stock in data that they perhaps shouldn’t, and making inappropriate - and perhaps expensive - decisions based on it.)
this is in houston?
lolol
I gotta get out there
No rain check (40% threat of rain at all times at Alkek, that’s Houston for you!). With this being a fundraiser for Alkek, if it rains…well the track needs funds to patch holes. We’ll be there either way.
Great point on the anemometer we have one to set up that should help us interpret the data even more accurately.
$15 seems like a great deal. I wish this was a week or two later so I’d have my new P3 built up. Doesn’t make much sense to do position testing on a bike I’m getting rid of.
With this being a fundraiser for Alkek
I missed that part - good on ya!
We’ll have others as the spring/summer progresses, hope you can join us for one. Enjoy that new P3.
We’ll have others as the spring/summer progresses, hope you can join us for one. Enjoy that new P3.
you have any power meters for 650 bikes?
If you could synchronize timers on the device recording wind speed and direction and the power meters
then you could normalize everything =)
Well, at least in theory. However, having spent plenty of time in the infield of tracks like Alkek, I think the only way you could really get accurate wind-on-rider measurements is if you had anemometers every 10 m or so along the pole line. Moreover, even if you had data for the actual wind speed and direction experienced by the rider, it would still be difficult to compare runs where these things differed markedly, because CdA itself can vary as a function of yaw angle.
Sorry, all of the PT’s are 700’s.
If you could synchronize timers on the device recording wind speed and direction and the power meters
then you could normalize everything =)
Well, at least in theory. However, having spent plenty of time in the infield of tracks like Alkek, I think the only way you could really get accurate wind-on-rider measurements is if you had anemometers every 10 m or so along the pole line. Moreover, even if you had data for the actual wind speed and direction experienced by the rider, it would still be difficult to compare runs where these things differed markedly, because CdA itself can vary as a function of yaw angle.
That’s where some good old kinematic simulations come into play. Fortunately since I’m in Houston I’ve got plenty of flat loops that are also plenty breezy to validate my techniques/reduction methods and sims against. Alkek can be a little tricky IMO because of the line of trees on the south side of the track. Having raced out there I’ve felt the winds behaving somewhat differently at either end. Near the pole line at the track you do experience a fair amount of wind on breezy days.
The benefit of testing out there would be to look at lap times and also knowing how to interpret the speed variations.
We’ll have others as the spring/summer progresses, hope you can join us for one. Enjoy that new P3.
Just make sure you post a little more advanced notice and I will definitely make the drive over from Austin. I’d love to be able to test some helmet, wheel, and even bottle setups in a controlled environment.
We’ll have others as the spring/summer progresses, hope you can join us for one.
Great, since I will be skiing this Sunday. Post here again when you put on another event like this. I am definitely interested.
That’s where some good old kinematic simulations come into play.
That is precisely what I was suggesting, but again, that doesn’t enable you to confidently compare across trials where wind speed/direction vary markedly because CdA itself often varies as a function of yaw angle.
AC,
I’d definitely be interested in taking part in the next session they do of this to try some different bottle setups, helmets, and maybe some position changes. I don’t want to end up with a bunch of incorrect conclusions, though. I wouldn’t know where to start on the math even if there were anemometers in multiple locations around the track. In order for the testing to be useful, is there a protocol you would recommend? Multiple passes for each configuration, for example, to minimize wind variations? Something else?
Since I’m looking for relative performance of setups, actual CdA isn’t as important as the delta between the runs.
AC,
I’d definitely be interested in taking part in the next session they do of this to try some different bottle setups, helmets, and maybe some position changes. I don’t want to end up with a bunch of incorrect conclusions, though. I wouldn’t know where to start on the math even if there were anemometers in multiple locations around the track. In order for the testing to be useful, is there a protocol you would recommend? Multiple passes for each configuration, for example, to minimize wind variations? Something else?
Since I’m looking for relative performance of setups, actual CdA isn’t as important as the delta between the runs.
If total mass, wheels, tires, tire pressure, and surface are essentially constant, then multiple 1-2 km efforts at the highest speed you can reproducibly achieve might be the best approach in this case (cf. Table 5 of this article http://velo-fit.com/articles/coggan-power.pdf for an example of this approach). Just make sure that you avoid the common trackie habit of dropping down the banking right at the start of each effort to get rolling…either come down early, or “give it some stick” to get up to speed far enough in advance for power and speed to be at steady-state.
As for wind, not much can be done about if after the fact, but if you can lay your hands on the anemometer data you might at least be able to figure out which efforts to trust and which ones are questionable.