Those strain gauges read the torque generated by both legs not just your right one.

Hugh

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Genetics load the gun, lifestyle pulls the trigger.

My basic understanding:

SRM measures total power. So it will get it all.

Just be cause you are left handed does not mean you are left legged. I thought my right leg would be stronger because I am right handed and because in kickball I always kicked with my right leg (felt natural), however, my data shows that my left leg is (slightly) stronger than my right leg. I would still feel uncoordinated trying to kick a soccer ball with my left leg. I'm not saying that everyone is like this, I'm just saying that just because you are left handed and kick a ball with your left leg does not mean your left leg is stronger.

My left leg is 4-5% weaker from my right left and stages are always showing less power in comparison to my Garmin vectors. Training wise if you only use one power meter it is totally irrelevant especially when using for pacing at or below FTP. You are loosing some interesting data about % of the effort and leg unbalance, and your pedaling style, also cleat placement https://www.instagram.com/p/BE2IZ8OS6Kz in the case of Vectors, but those are still unexplored areas, or at list not well documented by those that understand it.
Having single leg and dual leg power meter, I prefer dual leg and using stages only on my CX bike.

No. SRM measures power at the crank spider. This type of power measurement takes into account both legs. The only place this is an issue is with left-side only power meters, like Stages (not to pick on them as there are others). For example, if you produce 45% of your power from your left leg and 55% from your right, than at 200 watts for example, Stages will take 90 watts from your left leg (45% x 200) and double it to get total power. So it will give you a power reading of 180 watts. As long as it's consistent, you can still train to it, so it's not the end of the world...but that is the limitation of a left-side only pm.

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Power Meter City
Your Power Meter Specialists

I show the same issue... i estimate I'm 4-5% low on my left leg based on aero estimates. However, the problem is that this differential varies, so a Stages may not be linear or consistent over time, but it's probably not far off.

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TrainingBible Coaching
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You are making the mistake of thinking about placement of a power meter in terms of lateral location on the bike, rather than where along the drivetrain it is measuring strain.

Anything measuring strain and velocity downstream of the bottom bracket (i.e. at the crank spider, chainrings, chain, cogs, hub, wheel, tyre, or in case of some trainers anything downstream of the rear cogs such as internal chains like the Wattbike, or the tyre roller electro resistance unit like the Computrainer) will be measuring the total net power delivered by both legs through both crank arms, less a bit for drivetrain losses. Examples include SRM, Quarq, Power2Max, Powertap's hub and C1 chainring meters, Polar's old chain based meter, G-Cog, and bike trainers that use direct drive or tyre rollers to record strain and velocity and convert to power.

When you place the strain gauges upstream of the bottom bracket (i.e. crank arms, pedal spindles, pedals, cleats/shoes), then you need to measure strain and velocity on both of the left/right pair in order to obtain total power output. Examples include Garmin Vector pedals, Powertap P1 pedals, Pioneer.

If you only place a strain gauge on one of those upstream items in the left/right pair, then you are no longer measuring total power, but rather the power from one side only (unilateral measurement). Examples include Stages, 4iii and other variants on a theme. Such meters then make an assumption that total power is always double the unilateral measurement. As a result of normal human variable asymmetry in cycling power production, the error introduced by this assumption is both variable and unknown (unless you are also accurately measuring bilateral power with another device).

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Simply because you are preferentially max force dominant on one leg does not imply that it will be the superior side wrt sustainable aerobic power output. It might well be but I would not make that assumption.

I had a lower leg amputation, yet post-amputation managed to achieve my pre-amputation aerobic power output despite having a severely weakened left leg. The reason is pretty simple - sustainable aerobic power while cycling involves significantly sub-maximal forces.

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