Using A Power Meter: Power Curve.

In my effort to combat the effects of arthritis I had managed to overcome the knee pain hurdle by slowly increasing my cycling distance and intensity. I also had a cortisone injection !

Having made some good gains cycling outdoors I could see myself losing this initial fitness during the winter so bought a turbo trainer and joined Trainer Road. Full details of this are HERE.

The decision to buy a power meter was made easier with the introduction of the Stages Power Meter, why ? Price. I did consider the Powertap G3 hub, but the hassle of having to get it built into my wheel put me off, it would have meant a week of missed training with me driving to our NOT LOCAL bike shop.

So now I've used power for training, what next.

The other thing Trainer Road does with my data is that it builds up a power curve. It uses the power I am able to produce over given time periods.

It builds a graph with this data. All the above data has been gathered during my training sessions which have been Sweetspot Intermediate Base 1. I won't show you the program, you'll have to join Trainer Road.

I also use Strava, and the premium version will also build a power curve for you. I upload my Trainer Road workouts to Strava but I can also include my outdoor rides.

Today I went out and did a 30 second all out sprint, and then a 5 minute paced effort, they were both on uphill Strava segments.

http://app.strava.com/activities/121733658

You can see three of my attempts on this segment. Position 3 and 2 were last year when I had started building my strength outdoors. In October I beat my September result by pushing the lap button and trying to beat my previous speed.

I achieved my fastest time yesterday by pushing the lap button and simply looking at the Watts I was producing. Time and speed were not an issue, I knew it would be 5 or so minutes and what wattage I hoped to produce.

Overall on the segment this gave me a pretty good result.

I did well, segment wise and I also gleaned valuable power information. I actually paced the 5 minute effort, based on recent efforts so that I didn't blow up halfway into the 5 minutes.

I now know that I should be able to maintain 267 watts over 5 minutes.

The Strava curve also gives you Watts/Kg.

Now for comparison. My 4 w/Kg would make me CAT4. The pro riders are pushing out 6-7 w/Kg !

So to stand a chance I would have to increase my 5 minute power from 267 watts to 462 watts !!

After my training is done I'm going to be doing an FTP test, more about that later.

Stages Power Meter Battery Drain !

If your don't want to read the whole thing then hit the link below for the very short summary.

Updates and complete timeline now here.

I have contacted Stages to see if they can help as I'm in the UK and the unit was purchased for me by a friend in Colorado Springs.

I emailed Stages Technical about the problem on 22-Feb-2014.

Well the first battery lasted for a total of 7 hours riding time. I didn't panick at this stage although it had not quite achieved the claimed 200 hours !

I replaced the battery with  new one. It lasted around 5 hours. The third Duracell is being taken out when not in use.

The sad thing is that Stages haven't made an Android app so I have to take my bike to an iPad user to get the data. If there was an Android app I would leave the battery in and check it throughout the day.

Duracell battery put in the day before but removed overnight.

My firmware is up to date 2.0.38

I don't see the point of the zero reset, it merely shows you a figure and doesn't reset anything to zero !

Don't know what the slope or DPOT values are for.

I have discovered that the earlier ones shipped to the UK had similar problems.

Tri Talk Forum    and here   Bike Radar Forum

I decided to perform a test on my 'unworthy' Android device as it does support Bluetooth 4 and so can see the power meter when its awake and transmitting. 

Look at the times in the upper right. I had woken up the device in the first pic and then let it alone for ten minutes to put it back to sleep. You can then see me searching for it at 15:06 and it is not found after several attempts. I backed up this test with the Garmin Edge 500 and the same thing happened for ANT+.

I have decided to leave another battery in and check it tomorrow night if I can get access to an i-device.

It's now the next evening 24-Feb-2014 at 18:30 GMT.

No reply from Stages yet. I will link this blog on their Facebook page.

The battery has been in place for 30 hours but only two of those were spent cycling.

No access to an i-device tonight so lets try the Excellent Trainer Road.

Trainer Road attempts to find Stages Power Meter.

Nothing happens. Also nothing on the Garmin Edge 500. I remove and check the battery on a battery meter which says the voltage is good so I replace it.

I get something but the signal goes from good to poor to bad. I'm going to leave it for another day, this time in the house.

Here is what I hope will be the penultimate update. I arrived home tonight to do my 1 hour turbo session. I had left the bike in the house overnight. I got ready, put on Trainer Road which detected my HR monitor. Then I spun the crank and Trainer road detected the Power Meter.

Got on the bike to start the workout and NOTHING, battery out battery in still NOTHING. Removed battery replaced with another new one and away we go, no problem. I later tested both batteries on a simple good/bad battery meter and they both moved the needle to the same good position. I'm baffled.

The good thing is I got a very good and detailed response from Evan at Stages who is going to send outa new one. That's why I hope I'll only be making one more update to the blog :)

Updates and complete timeline now here.