Adventures with a Power Meter 6: Lessons Learned

June 22, 2018


I want to get faster and stronger on the bike and have set myself a goal of riding a 10 mile time trial in less than 30 minutes. To help me train towards this goal, I’ve been using a power meter. I’ve had one for a couple of months now. What have I learned in this time?



Garmin Vector 3S


The power meter I’m using is the Garmin Vector 3S single sided. This replaces a Look Keo pedal. This was fine for me because I was using SPD-SL pedals before and they are pretty similar to Look Keo so it wasn’t much of an adjustment. This is the only power meter I have ever used. Other power meters replace different parts of the bike and you can find out more here


Being pedals, they were pretty easy to fit, just like any other pedals. Plus a key advantage in that it’s easy to switch the pedals to other bikes.


Connecting and Calibrating


As soon as the power meter was on the bike, my Garmin detected it. The key things I had to do to calibrate the meter was to make sure the correct crank length was in the bike settings on the Garmin, then follow the instructions it gave for calibrating. One of the steps with my Garmin set up involved cycling at a constant 80-90 rpm for a few minutes which I found easiest to do on rollers indoors rather than out on the road.  And that was it. I was up and running. Or cycling I should say.


You need to recalibrate every time you take the power meter pedal on and off the bike, for example, if you are switching the meter between bikes.


New Batteries


The Vector 3S uses two LR44 button batteries. I was disappointed that within a week a message appeared on my Garmin 810 screen saying the power meter battery was running low. However, the new batteries I put in lasted two months at a usage of around 8 hours a week, a total of approx 65 hours. This is about half the 120 hours claimed in reviews.



It was very easy to change the batteries. It’s an opportunity to use your bike multi-tool. You know, the one you keep in your saddle bag for emergencies and never usually sees daylight. Just be careful putting the new batteries in, making sure they go in completely straight. Otherwise they might get stuck and you have to find a skewer in the kitchen drawer to prise them out again.





Power meter Ecosystem


A power meter on its own doesn’t achieve very much. When I first had it on the bike, it gave me a new set of numbers to look at rather than focussing on speed. But the numbers on their own are pretty meaningless. You need to do something with the numbers.



So you need something to collect the numbers and a way to make sense of the numbers. You may even need someone to help you make sense of the numbers.


I already had a Garmin 810 cycling computer which collects the power meter data alongside ride details. I upload the data to both Strava and TrainingPeaks for analysis. And Will in the shop helps me make sense of the readings.