AeroPod, PowerPod and Newton

Dragged the TT bike out to a few races recently, then used it for a comparison with my DFPM. It's a single sided Favero Assioma, which has proven faultless so far on multiple bikes, and reproduced data calculated from bikecalculator.com with very good precision on road and TT bikes on closed circuits. Sorry to say, but it is even easier than the PP to swap between bikes (just need the Park HT8 Hex wrench).

Anyway, after resetting my arm position to horizontal, and rotating the PP forward (it's mounted on a dual Garmin mount on the extensions), I rode 33 laps of a closed 0.9 mile circuit with both PP and DFPM. No aero toys or wheels, save for a helmet, and the windiest of windy windy days - 25 mph!

Of course the original data said that I was 500W plus - hello Tony Martin! So after tweaking the net average wind speed to zero - it is a closed circular course, and a little extra tweaking of Crr (0.0035 for 25c Schwalbe Ones with latex inner tubes) and CdA (0.235 I'm pretty aero with a flat back), the results look rather promising. The CdA from Issac doesn't change in the plot because I did not get out of position at all - I've confirmed on another ride that it detects when I sit up on the base bar - but I do want to move to more accurate testing with changes in wheels, skinsuits, and of course position (slightly higher arms). I think 11 laps (which is the usual race distance) will be plenty for proper testing.

So onto the Aeropod next... I've backed and am looking forward to the Garmin connectivity and iOS setting. But here's a data point for anyone interested in seeing some data. File attached including DFPM data.

My other PP is being fixed, and then will most likely be moved to my fixed wheel road bike (it's seen action there before and was great). I'll calibrate it again against the Assioma and leave put. When the aeropod arrives, I'll lend out the original for others to test.

It's hard to believe that carrying around a Part HT8 Hex wrench is easier than rotating a GoPro screw with your hands, but whatever...

You're right, this was a very windy day!

The first 8 minutes of PP data were off, while your PP automatically recalibrated itself. Then, all was good.

I removed the first 8 minutes of your ride, then used the "tweak CdA" command to find your CdA. I get .232.

I like your approach and I like all the data. The more data you get for CdA, the more dialed-in the CdA number is going to be!

Thanks John. Very windy, and I would not normally do calibration on such an evening. But I’m very happy with the tool and now feel confident with the software.

Like anything, there is a learning curve to get the best results, but having a DFPM has only improved the PP experience.

Good luck with the aeropod.

Oh and for tweaking CdA , I selected portions of the ride where I was absolutely steady lapping at 200w then switch the stats button between DFPM and PP ensuring that average and Normalised power do not change. There are a couple of harder race efforts in their to spread out the sampling space.

Nice technique! You are doing a great job using both your PP and DFPM to get solid results.

Another file for your records - again a windy day on the same circuit. This one was a 10.3 mile TT race (11 laps), so faster than calibration ride. Same Crr and CdA as before. But in this race I was going faster into the double bends which meant that I couldn't stay in position. Ignore the first few minutes, as PP was calibrating after I'd altered the front (again). Agreement is very good, but as I would expect, the PP has a wider distribution due to the very windy conditions that day.

I paced this series of races solely on PP last year. Readings were a little higher, but the use for pacing was absolutely rock solid.

I'll get some still data soon for the poster shot, and you are free to use them as you see fit!

EDIT - in fact it was the warm up - I'm a bit faster than that! Then stopped and forgot to start the PP again for the race immediately afterwards!

Yes, please more data and images!

Another race tonight. Moved the PP onto a Garmin out-front mount to try and hide it. Raised the arm rests a bit to clean up the front end for more power (maybe).

Calibration of 10 laps to set wind scaling (another windy day!). Then rode the race. Combined the data with my DFPM and here is the output. More details on this post http://www.timetriallingforum.co.uk/ind ... ce/&page=4

You'll see the nice clean mounting, the calibration ride, where PP needs to adjust to new position and tilt, and finally the race. Took a while to get an accurate merge of the DFPM and race data, but all good and very pleasing. Now to see whether I'm more aero and have better power!

Full calibration ride. NOTE power should be off for last bur one lap because I am sat up on the base bar (hence CdA is higher than model expects). My point is that after a little work, with wind calibration etc, you can get some very nice data indeed.

Today was the big day. Perfect testing conditions with no wind. Sadly I updated the firmware last night and my PP just flashed its green light and never joined the party. Tried everything including the full on 10 secondshard reset. Does the firmware update give a hard reset? Isaac suggests another usb communication upset. It sees the PP then drops off. Was it hoping to pair some ANT devices? I could not upload my DFPM calibrated profile as the PP was not recognised. Not bothered about the profile per se, because I can always process the raw data against the DFPM.

A real shame because I tested six position with careful replicates of seven laps per test (1.9 km per lap on a closed circuit) all at 200 Watts with about 1-2% variability we lap. Will see what Golden Cheetah has to say. Was hoping to impress one of the aero gurus also testing today. I plan on lending him a PP too.

Looking forward to my aeropod. Dynamic CdA on one segment of this course would be great for testing.

Yikes, the FW update should have no effect on pairing.

Please email me at jhamann@velocomp.com for next steps.