My First Ride with AeroPod

[Graham]

I used Aeropod for the first time on Sunday. Pairing to my power meter and speed sensor first was straight enough thanks to the video and calibration also was OK with no issues. I have attached the ibr files. I ended up with 2 files from the ride which I have attached, I have also merged the GPS data from my Garmin into the files. If you could answer and confirm a few setting please and give my data a look at as I think I have an anomaly at arround 36mins to 40mins in the larger data file.

I was testing my TT helmets on an out and back route using my TT

1, In setting up the device I used "out front" as mounting type I have the supplied TT mount, is this correct?
2, I have a SRM power meter, in the settings there are several SRM PM as I'm not sure which I have I left it as other, will this affect things?
3, The total ride length was 25.66 miles (1 hour 12 mins 42 secs) 1 file on my Garmin but this does not tie up with the data files I have from the AeroPod looks like the begining of the calibration is not recorded.This makes it not align with my ride notes as I used the Garmin distances and time. Is this normal to miss the beginning.
4, My power data would not show for 30 secs or more after I started to ride again, my stops were short as only changing my helmet. The last couple of runs I pressed the button on AeroPod it flashed green but did not seem to change the way power display the other 4 data fields show live data straight away.
5, I rode the calibration using a Areo road helmet and continued till 7.54 miles in my Garmin file
Changed to the Kask Bambino and rode till 12.07 miles
Changed to the Giro Selector and rode till 16.64 miles
Changed to the Rudy Projects and rode till 21.20 miles
Changed to the Kask Bambino and rode till 25.66 miles
The wind was according to "My Windsock" was a 10 mph cross wind so I guess this has some what hampered the aero testing, what your opinion from the data?
6, The anomaly with my DFPM data and AeroPod power at 36 mins in.
7, I have available a PowerTap G3 hub or Garmin Vector pedals , do you think I would be better using one of these? I would prefer to stick with the SRM but if it is an issue I will swop it out?
8 I have the option the option to test on the local closed road cycle circuit with a good surface and I can get on there on my own its 0.8 miles in length but has 7 bends I can stay in the aero position on my TT all the way round but have to stop pedalling on 2 corners. Can be susceptible to the wind though as close to the coast. Would this be OK for aero testing including a calibration ride?
9, I tried to upload the gpx file as well but the forum would not allow it?

Thanks in advance and I look forward to more testing if the British weather this time of year allows it
Graham

[Velocomp]

1) The first of the 2 ride files is the one that establishes your default CdA, from 70-100W.

2) Your long ride file is the one immediately following the short one. I used the "Edit/Append Ride File" to merge the two into one, longer ride file. This is close to the length of your Garmin file

3) The first part of your calibration (0-70W) is not recorded. This is why the appended file in 2) is still a bit short

4) I tried to place lap markers where you changed helmets. You will see my guesses in the ride file attached.

5) AP retransmits your SRM data. From your ride file it looks like cadence was zero after restarting your rides; this would force displayed power to zero. Cadence is coming from your SRM. I don't understand why you are getting zeroes.

6) Wind data looks good; I don't think cross winds are affecting things much

7) SRM is fine, though I am puzzled about the zero cadence data

8) It sounds like your cycle circuit is not a great choice; the bends might be a problem

9) Put your gpx file in a zip format and upload that!

Here are the results I got for your ride file. The first number is the average HR for the section; the second is the associated CdA.

The helmets seem to be very close!

Areo 59.7 .239
Kask Bambino 59.5 .238
Giro Selector 59.2 .237
Rudy Projects 59.8 .239
Kask Bambino 59.3 .237

[Graham]

Thanks for the reply and looking at my data files
I've zipped and uploaded the gpx file if that's any use to you

can you confirm I am using the right "Device Mount Location" as Front Mount with the supplied TT bike mount in Device Setup?

Was expecting/hoping to see bigger differences in the helmets, I will redo the test on a calmer day.

A couple of other questions

1, Towards the end of the calibration the road had a slight down hill, thought the piece of road had longer enough flat section for cal ride, am I better finding a more flatter road?
2, There also seems to be some "Slope" anomalies at the 42 to 46min mark in the combined data file?

Thanks again
Graham

[Velocomp]

Thanks for the reply and looking at my data files
I've zipped and uploaded the gpx file if that's any use to you

can you confirm I am using the right "Device Mount Location" as Front Mount with the supplied TT bike mount in Device Setup?

Was expecting/hoping to see bigger differences in the helmets, I will redo the test on a calmer day.

A couple of other questions

1, Towards the end of the calibration the road had a slight down hill, thought the piece of road had longer enough flat section for cal ride, am I better finding a more flatter road?
2, There also seems to be some "Slope" anomalies at the 42 to 46min mark in the combined data file?

Thanks again
Graham

Thanks for posting the map file; it was really helpful in understanding your test route!

I think the route a good one.

Your calibration ride is fine.

At minute 42 you bumped the AeroPod and rotated it to a different position. It took a few minutes for it to readjust.

Mount location in Device Setup is irrelevant; AeroPod will automatically recalibrate itself based on the actual position of the device on your bike.

One important thing: there are sections in the ride where you have zero cadence, and therefore zero power. In looking at your .zip file, the SAME zero cadence and power shows up. So, both your Garmin and your AeroPod were seeing the same data. This means your SRM was not transmitting power and cadence in those sections. You might want to check to be sure your SRM is working properly.

I agree that doing testing on a calmer day would be a good idea. You can see differences in measurements between the "out" portion of the ride and the "back" portion. With calmer winds this should be minimized.

[Graham]

My SRM has performed faultlessly since I have had it and the batteries are fresh in SRM battery life terms. But that's not to say it did not develop a fault when using it last time out. What I can do is use another Garmin just paired to the SRM and compare the data to the Garmin paired to the AeroPod next time out.
Graham

[Velocomp]

Ahh...so your Garmin was paired to AeroPod. That would explain the consistency of the data.

As a precaution, do a hard reset of your AP, then reset its date/time using Isaac. Hopefully that will fix things.

[Graham]

I did another test this Sunday, same road but the wind was a bit calmer than the first time. the first time I had a 10.7mph cross wind from NNE direction, this time the wind was still a cross wind from a different direction,with a speed of 7.5mph, from the south. I did a hard reset as suggested and sent the seupt file again to the device. The pairing and cal ride was carried out without issue.

I tried different helmets again,

I wore the Kask Bambino with the visor clipped up for the cal ride and upto 2.4 miles into the ride
I then used it again with the visor in place upto 5.1 miles
I then changed to the Giro Selector upto 8 miles
I then changed to a Std Road helmet with multiply vents upto 10.7 miles
I then changed to the Rudy projects upto 13.5 miles
I the went back to the Kask (visor down) upto 16.3 miles - this run showed a really low CdA on the Garmin down to 0.145!
I repeated the run as the values seen did not seem correct

A total of 19.1 miles in the second recorded file on the AeroPod for the day

I am getting more familiar with the Isaac software to analyse the results but I am not seeing the repeatability of CdA values I was hoping to see.
The CdA value changes quite considerably during the ride without me changing my position at all. There is also an anomaly with the slope data between 13.5 miles to just after 15 miles giving a false CdA value I believe. I did not knock the AeroPod or any thing like that, only difference was the time to change helmets as I was chatting to a friend who came by, but a couple of minutes only. Although it was a calmer day there still was a significant cross wind, Is this having an adverse effect on my data? You can see a difference from the aero helmets to the std road helmet but I do not feel the results between the aero helmets is valid enough to make an informed decision which is best for me. The first and last run with the Kask (visor down) do give the same average CdA value for the complete run but different in different section in the same direction.

The weather forecast for next week end is not good here but its looks better the weekend after when I will have another go. I will make sure that I come out of my aero position at the same point as best as I can do to start braking and make the turn around see, if this helps with getting more repeatable data. Although I did this to a certain level before but will be more precise next time

I have attached the files if you could give them the once over and any feed back from your side John, The gpx file is from my Garmin 500 which was paired direct to the SRM not AeroPod.

If I my make a couple of suggestions that could help with data analyse,
1. At the start of a new run, you press the button to place a lap marker and reset the time advantage to zero. (an option within the device setup)
2 Be able to make "Strava" like segments in Isaac using merged GPS data so you can analyse the result more easily and accurately.

I am using Isaac 4.1.1 and believe there is a new release in the process

Cheers
Graham

[Velocomp]

1) You can merge your GPS data into the AeroPod ride file using the command "File/Merge GPS Data..." After you do this, if you save the ride file then the map information will be saved too. I attach the merged ride

2) Wind data looks much better

3) Something knocked your AeroPod out of position at minute 22 (mile 8), and later again at minute 36 ½ (mile 13.5). I can see these changes in the internal "slope offset" adjustment. Whenever AeroPod is moved, it takes 5 minutes for the slope correction to work. So, your data from minute 22 to minute 27 is invalid, and from minute 36 to minute 42. Make sure that your AP is rock-solid tight on its mount.

Also: please post a photo of how you have AP mounted to your bike.

[Graham]

AeroPod is mounted using the supplied TT mount to a Giant Trinity base bar as per instructions and is firmly mounted. It did not come loose during the ride or get knocked. I did not ride over any pot holes, the tarmac surface does have small imperfections but nothing you would not expect to see on a maintained public road. I can get a picture of it later tonight when I get home and post it for you to look at.

Is there anything else that could be at issue?

I am aware of the "merge GPS data" and have done that but its still not as precise as defined GPS points to select segments.

Please do not feel that I am unhappy with AeroPod's performance and I realise that in field CdA measurement can be fickle at times I just want to get it as precise as possible to find the the marginal gains in my setup

Graham

[Velocomp]

Hi Graham:

I do not take your comments in any way negatively...

SOMETHING is causing AeroPod angular position to change; of that I am 100% certain. Once I see your photos I might be able to make some educated guesses.

[Graham]

Pictures Attached

[Graham]

2

[Graham]

3

[Velocomp]

Assuming your extension posts above the TT mount are stiff, your setup looks really good!

Make sure your mount has no wiggle and that the AP bolt is really tight, so there is no possibility for AP to rotate. Do another ride when possible, then post the ride...

[Graham]

The extension posts above the TT mount are the std Giant riser blocks for the aero bars they are solid aluminum and they sit in a profiled recess so everything is sitting square and flat before the bolts are tightened, which are the same bolts holding my left aero bar onto the bike, and they are tight and secure. The reason there is a profiled recess under the base bars to allow the bars to be flipped over for different riding positions, which lends it self to providing a good flat surface to work with when mounting the AeroPod.

Not sure when I will be able to get out again due to the weather this time of year in the UK.

Thanks again
Graham

[ruud_g]

I can relate to the slope swings although my setup is also quite solid (Aeropod firmly positioned) which cause a lot of flutuation and re-calibration in my measurements unfortunately. The algo is very sensitive and for some cases just too sensitive in the field IMHO. Still have to make a ride with another bike to see if same things happen on that one

[Graham]

Is it possible that the issue with the slope is related to when the bike is stationary. The reason behind my thinking is that the AeroPod has not changed angle relative to my base bars during the ride. But AeroPods angle does change relative to the ground -
1,When I lean my bike against my car and the bars swing round on the steering axis which puts AeroPod at a fairly steep angle.
2, When I make a U turn in the road and have to give way to traffic, again bars swung round on steering axis

The 2 instances you point out John are just after a stop or a U turn and Aeropod would be at a considerable different angle for several seconds?

[Velocomp]

Is it possible that the issue with the slope is related to when the bike is stationary? The reason behind my thinking is that the AeroPod has not changed angle relative to my base bars during the ride. But AeroPods angle does change relative to the ground -
1,When I lean my bike against my car and the bars swing round on the steering axis which puts AeroPod at a fairly steep angle.
2, When I make a U turn in the road and have to give way to traffic, again bars swung round on steering axis

The 2 instances you point out John are just after a stop or a U turn and Aeropod would be at a considerable different angle for several seconds?

This is a great insight. Yes, stops or sharp U turns can mess up the CdA algorithm for a bit. We are working now on an update to address this situation.