Monday, October 21, 2013

Crash test dummies

Following my Aero Testing for Dummies post the other day, I've been getting questions about aero testing services and when people can start getting tested, as well as general interest in progress with the project. I won't go into business plan detail but will post casual updates here every so often, and eventually when it's ready for full professional service delivery, I'll update our website (this is a primarily a personal blog, not a commercial one).

This is a sample of the comments:

Sounds like a terrific service. Good for you Alex, am sure it will be a big hit. Be cool to incorporate with a 'dynamic bike fit' service too - make a change to bar drop/saddle height etc, do a lap while you test comfort and aerodynamics. 
It's right up my alley - am trying to think of an excuse to get back to Sydney now.

This technology and service is a perfect complement for bike fit services.

I have no personal desire to do professional bike fitting, I'd rather provide aero test consulting services to professional fitters and/or work in tandem with them. Indeed I'd prefer a bike fitter be involved, so they can learn about the impact of their fitting and equipment decisions on the rider's aerodynamics, power and speed, and make the adjustments with the benefit of my analysis, feedback and advice. I'm sure over time they will get better for seeing such information, as will I.

I can't say much about what's in the pipeline but I expect the system may well ultimately integrate with professional fitting tools so that rider/bike fit and aero data can be managed for ongoing reference and development.

And similar to bike fitting, much of the quality comes with the knowledge and professionalism of those providing the service. The tools are an enabler and/or help with efficiency. The difference with this tool is the results are immediately apparent, objectively measured and precisely quantifiable.

Next up for me is what I've called Phase II - Demonstration testing

This is where I'll do some properly controlled testing over next month or so, but the emphasis will be on nailing the process, getting good aero results and giving people the opportunity to see it in action, and not so much on commercial considerations beyond refining operational processes for efficient use of testing time.

I already have some crash test dummies lined up.

Once I am satisfied with that I'll move to full professional service delivery, and provide some clearer guidance on services and pricing.

I'm hoping to get to Melbourne at some time before long and there's reasonable a chance I might be heading to Tour of Bright to work at the race and perhaps I could do something at the Wangaratta track around that time if anyone is about and logistics can be arranged - but that's just a thought bubble for now.

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Saturday, October 19, 2013

Aero Testing for Dummies

Just lately I've been having some fun with the Alphamantis aerodynamics testing system here in Australia.

In a nutshell, this system enables me to precisely assess changes in a rider's aerodynamics in real time while they are riding their bike.

The rider does not need to do anything special other than ride their bike around a suitable track. Any regular oval-like cycling track or velodrome will do, although an indoor velodrome is preferred as environmental conditions are far more predictable indoors and of course you won’t get rained out.

All that's needed is an ANT+ power meter and speed sensor on the bike, and a clear track to ride around, one where the rider can maintain position and does not need to brake.

Do a handful of laps, and we have your CdA baseline number. Then make a change to your bike position or change a piece of equipment (e.g. helmet or wheel), do a few more laps and we can tell immediately if you are getting an improvement, and by how much. Lather, rinse, repeat.

Test while riding, know if the position is rideable, how it feels at race pace, as well as whether or not it is faster for the power you have, and by how much.


Here's a 7-minute long video showing a sample of it in action, with me explaining in voice over.

That's just a sample of the data capture, there are lots of other things but that's the essence of it.

I've been in a systems testing phase these past couple of weeks, and have successfully tested the system with two riders using different power meters (one an SRM, the other a Powertap) at the Dunc Gray Velodrome. Apart from Rod, who's data was featured in the video, the other rider was my mate Tony. It was only a systems test, not a properly controlled aero test, nevertheless we were able to quickly discern for Tony a difference between two good aero helmets.

The next phase will be to demonstrate for those interested in seeing it in action, in particular those with a professional interest in aerodynamic related cycling performance improvement such as bike fitters, coaches, squad development people, and organisations that have tracks. Australia has over 90 velodromes/tracks to choose from!

The system is portable, meaning I can set it up anywhere with a suitable track, so if there is sufficient interest and access to a clear track, I can travel. All I need is access to a regular 240V power outlet and maybe a table and chair for convenience.

How it works:

Power and speed information from your bike's ANT+ device is transmitted wirelessly to special software on my laptop which, along with various parameters (e.g. rider morphological data, track geometry data, rolling resistance and environmental data) and track timing tape data, calculates and plots charts of power output, speed, CdA, exact track position and so on. It does all this in real time.

There are lots of calculations going on underneath (viewable if desired) such as centre of mass speed, lean angles, precise lap distance actually ridden and so on. And more work is being done to further refine the already sophisticated physics modelling, e.g. modelling the intra lap variation in rolling resistance/tyre scrub, as well as integration with individual track timing data systems for even more frequent precise positional data.

The system also works with the Alphamantis "aerostick" device that can additionally capture the relative wind speed and yaw angles, enabling the software to parse out the effects of any wind during testing.

All the data is also captured for reporting, additional analysis, as well as replaying the data to the rider afterwards if desired.

It is, very, very cool.

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Monday, October 14, 2013

Power meter usage on the rise at Kona

The Kona World Ironman Championships is over for another year. As part of event registration, the organisers do a count of equipment choices, and this includes power meter brand if fitted to a competitor's bike.

So just for fun, I thought I'd look at the prevalence of power meter usage by Kona competitors for the last five years, including this year. I managed, with a little help from the wattage forum and Google, to locate the data and compiled them into table and chart form. Click on the images to see a larger version.

So while competitor numbers at Kona increased by 36% over the five years 2009-2013, the number of power meters installed on competitor's bikes over that same period increased by 174%!

We can see three major power meter brands: SRM, Powertap and Quarq, have dominated the Kona power meter landscape to date, with Quarq in particular showing strong growth over this period.

Power2Max have begun to make inroads in recent years, and we can also see the emergence in 2013 of newer power meter offerings from Rotor, Stages and Garmin. The old Polar power meter is a distant memory, and ergomo usage never really got going, although a few souls were still using them up to 2012.

It appears the overall solid increase in usage of power meters by those competing at Kona has largely been satisfied by uptake of newer power meter brands. It would be risky to assume this translates directly into general market trends for power meter usage but it certainly provides a good snapshot of the trends for Ironman athletes.

The data on total bike numbers and power meter counts were obtained from these website links by Lava Magazine (2010-2013) and Triathlete Magazine (2009):

2013 Kona IM Bike Count
2012 Kona IM Bike Count
2011 Kona IM Bike Count
2010 Kona IM Bike Count
2009 Kona IM Bike Count

Links were active and  available at time of writing this post.

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