Left / Right Power in TR Performance Analytics?

Interesting. I went back and looked at my last lap suicide attack from last week’s crit, and sure enough… overall ride 49.2%/50.8% L/R balance, which is my norm (49/51) across most rides. When I accelerated the first time to 12+W/kg, I hit 56/44, peaked at 58/42, and then sustained the attack at 51/49. I’d never really looked at that before, and there’s nothing really actionable there, but it’s a cool theory.

@Trippy Just to be clear, I was talking about how it is stored in the .FIT file, not in the physical device.

I use v3 dual sided and record with a Garmin 920, That .FIT file gets to garmin connect full of detail.

IF I use the .FIT file from my wahoo elemnt (which is also recording from the Garmin V3s) the L/R data does not display fully in garmin connect, even though the wahoo elemnt shows the left right balance after a ride and wahoo say it is storing all the data. They blame garmin connect for the problem.

So I was asking about how the Quarq stores the data in the .FIT file and stores L/R data there.


Yes, a Quarq will broadcast left and right power for recording purposes if the recorder knows what to do or wants to. No, TR will not record it so it’s not passed on to Garmin Connect.

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I’ve been using Assioma Duos for a couple of weeks now. Thoroughly impressed with them in each and every way.

The LR data is interesting, if not confusing. If I am on a workout, I have the pedal data (LR, smoothness and torque effectiveness) going to my Garmin. It’s surprising how even a very subtle shift of technique /focus can make a difference in the readings.

When I was getting to grips with the pedals, getting the cleats dialed-in (I came from Shimano SPD-SL) etc, I was doing everything on my Kickr for convenience sake. So my first few workouts and data gathering was all indoor.

At low wattage, I see wide variation, but the gap closes as the intensity gets higher. For indoor workouts I have been consistently seeing Avg LR balance of ~55-45. When I saw this it confirmed what I already knew, that my repaired knee was weaker. I just didn’t feel it was so much weaker.

However, the few times I’ve ridden outside, my Avg LR is coming in around 52-48 or even 51-49. This had me scratching my head a little, checking my bike set up, checking that my Kickr is level etc. Everything checked out.

So, in summary I see better LR balance outside than inside.

I would like to see TR at least pass the info along to Garmin Connect, even if they’re not going to display/report it.


Likewise: recording the data in the fit file would be nice. For me, that gets pushed to Dropbox and then Golden Cheetah anyway.

So if you have a discrepancy what do you do to address it? I am 44/56 consistently.

You first make sure it’s real and not just a wonky power meter reporting incorrect L/R.


If it’s not wonky reporting from the PM, consider injury history and medical reviews of things like length disparity between your legs. If you don’t have history of either, then odds are you either have a mechanical issue with your pedal stroke which could be due to fit, or a severe strength mismatch in your legs which you would likely already be aware of. It’s pretty rare that people would have that much of a mismatch without a past injury or some other condition about which they’re already aware unless something else is really off.

My initial inclination is in line with GPLama… powermeter issue if there’s no other obvious cause.

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I’ve said all along, L/R metrics are not a one time measurement, it’s important to baseline your balance and watch it over time. A wonky PM would really only impact someone whom took one measurement, I would know if my numbers were way off from “normal” even though everything else felt the same.

I’m lucky I guess, I have two different L/R PMs, so if one went off the rails it would be pretty easy to detect. I really wish TrainerRoad would capture the L/R data, while the majority of users don’t have true dual sided PM’s it would certainly benefit those who do.

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I have Tacx Neo V1 paired with TR and Pioneer head unit.

It is really interesting that Pioneer Analysis software somehow display L/F balance even Tacx Neo V1 does nto support it.

I use real time power reading with Pioneer PM instead L/F balance on the road which is awesome.

I think L/F balance is so changable as it can get effected even the way you sit on the saddle. If you are looking for your real L/F efficiency, lets say, real time power can help.


Any way to validate this without another LR power meter?

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While I am looking into my LR data, I record the session on my Garmin head unit in parallel to TR. That way all the data is there in Garmin connect and can be exported for analysis.

As you mentioned though, it would be nice to have TR dump it all to Garmin for us :+1:t2:

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Not necessarily. When I first got my current PM, I went about a month without really looking at my L/R power, but when I went back and looked at it, I was at 72/28 pretty consistently even though the overall power numbers and cadence reported were pretty close to where they should’ve been… that was kind of dumb coincidence, but the issue was intermittent connectivity with one of the contacts in the pedal. Power didn’t drop out on my display, but it was reading intermittently (apparently) internally even after calibration. Garmin helped me fix it right away, but because I wasn’t really looking at the numbers, I didn’t diagnose the issue until I looked at the L/R data.

which is why I put in a suggstion for an enhancement to TR.

Check your saddle and fit too. If you are not stable on your saddle it could cause an imbalance.

Any word from TR if they will record L/R readings and at least pass onto Garmin connect?


@Nate_Pearson +1 just record it and let us look at it in Garmin etc.


Any update here? I’m trying to sort out a 60/40 power imbalance and am disappointed to see that TR still apparently does not have this ability (at least with connecting my Garmin Rally RK200 pedals to my iPad via Bluetooth). Where can one make a feature request?

Even if no visualization of this data was done in the Trainer Road app, it would be helpful to have the data recorded so it could be examined and tracked elsewhere.

  • This forum topic IS the feature request (hence the tag at the top). Adding your comments serve as the “+1” vote for it.

This is also true of HRV data. Just recording this does not make any user visible changes to UI, etc, so doesn’t complicate the user experience. Maybe once AT is all done :slight_smile:

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