Power2max question
 

I just scored a nice, used P2M Ngeco power meter and was wondering if the registration fee was worth it.

Was this the meter included in a new Cannindale? That’s the only one they should have an activation fee. Any other should just be a free online registration to your account.

Do you mean the fee to unlock L/R balance?

If you are talking about the $50 ish dollar fee to do the L/R metrics, I would pass unless you have a known issue there that you are going to work towards correcting.

My understanding is that most people have a slight imbalance in L/R power, but it isn't anything worth worrying about.

I never look at this metric.

I have a rather major imbalance there due to disc and other nerve issues. I'll watch to see what I need. Thanks.

It should be kept in mind that the Power2Max power meter (and any other spider based power meter) can't measure the the true right/left power balance. These power meters assume that all power generated when the right crank is descending is coming from the right leg, and all power generated when the left leg is descending is coming from the left leg, which ignores any power generated if either leg is is pulling up to any degree, or power loss if some of the power from the forward leg is used to raise the rear leg. As an example of the extreme case, if a rider takes their left foot off the left pedal and is pedalling with with the right leg only, then the R/L power balance should be 100/0. But if the rider pushes down with 80 lb. and pulls up with 20 lb. (right leg only), the Power2Max will indicate the power balance is 80/20. You can only get a true and accurate power balance with a dual sided crank arm or pedal based power meter.

100x this. Any measurement of L/R balance on a spider-based power meter is not accurate.

What would you do with an imbalance measurement if you had it?

I’ve dealt with a major imbalance due to a bad hip, since replaced. I used Garmin Rally pedals to track my improvement, and now I just use Stages left arm meters. Those are fine for me to gauge my total power consistently and cheaper for multiple bikes.

The Rally pedals are fine for power but a terrible pedal. There are better power pedal options, but I don’t think any of them are going to match top end pedals as pedals.