Single sided power meter?

I’m getting my first power meter (either favero assioma or vector 3) and I need some advice please. My cycling and reasons for buying are below:

I use my kickr core for training and will continue to do so up until march next year, which is when I want to start crit racing. I also want a power meter to gauge and pace the odd outside ride, when the weather looks less uninviting (so not much, in the UK). And of course I want a power meter for when I eventually start racing in March.

I’m torn between going single sided or dual sided. Obviously with single sided there is a massive cost saving. When most crank based systems in use are one-sided I don’t see why everyone is so fussed with dual sided pedals?

Can someone offer some advice, perhaps from experience that would be applicable to my situation?

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I have single sided vectors 3s pedals. Work brilliantly. There is never more than 2% swing on left vs right. So i cant see need for dual sided. Vectors are very accurate. Really gives u a massive amount of control and the trust you are riding within your limits.

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I don’t race, but will be looking at getting power meter in the summer. I will take the cost saving. As @Andy_Mills said can one side be that much different to the other side?

Agreed. I also have the Vector 3s and a Kickr Core. This is my 1st ever power meter and purchased spring ‘19. I pair the 3s w/TR during my inside workouts so that power readings during races and outside training rides are consistent with indoor training. The 3s works perfectly for me, and I am super happy with the setup. I’d be interested to hear from dual sided Vector users if they felt it’s worth the extra $$.

PS - I’ve always used Look pedals, and the Vectors seem identical to me.

I’ve got 2x left side and 2x actual power meters.
Actual is nicer, left will still get the job done.

The price gap between Favero Assioma DUO and UNO is not insignificant but it’s not massive either, I’d personally wait for a sale/save a little extra for the DUO.


Basically just repeating - single works fine double is better. Why? I have a single sided Cinch Power meter and on harder workouts I find myself favoring my left leg to maintain the number on the screen. It’s a potential benefit as I’ve always had a stronger right side, but it can be annoying. And of course single leg drills, but that’s a stretch. Not sure I could justify spending the money for dual sided power but I get the draw to it.

Single sided is fine if you’re close to 50/50 balance. If it’s your only powermeter you’re going to use, then it’s also fine.

Where the issues come in is where you have imbalance and using a single sided, and then use another power meter that doesn’t use a multiple one side style pm.

As an example, I just got a the assioma duos and at threshold power I’m 46/54 balance, If I had just the left powermeter, my 300w FTP would report 276w if I did a test, or if I had a right only pm it would report a 324w doing a test. Huge difference if I Also use my powertap wheel sometimes that reports a 300w FTP when testing.

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For ,onger, sustained intervals, single sided PM’s work fine. For shorter, more intense intervals, you can start to see more variance…the problem is you never know which way, or if it is consistent from effort to effort.

If you obsess over data and it’s precision and analyze to the Nth detail, then a single sided option is probably not the best choice. If your goal is to get “good enough” data, aren’t analyzing individual intervals for exact detail (ala DC Rainmaker) and are just using it for general TSS tracking, a single-sided PM is a great option.

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Dual sided power pedals reveal your left/right imbalance. This satisfies a curiosity while also potentially creating paranoia, if you’re so inclined to that sort of thing.

I have dual sided P1 pedals. If I had to go back to single sided, I wouldn’t lose any sleep over it.


On the contrary, I’d say if you’re already willing to splash the cash for single-sided, then the additional to go double-sided isn’t THAT much extra.

You take a look at both Favero and Garmin pricing on single vs double and the main hit is already there on the single.

Single sided is good, you’ll be fine.

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I use a Quarq XX1 dual side and have never used a single side. However, since I have a dual side I don’t think I could now ever use a single side PM. My last ramp test was 48/52 L/R Avg %. Over this past year I’ve seen disparity as much as 46/54 and about a half of the time 49/51 or 50/50. It seems the more varied the workout/ride the more varied my L/R is.

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Left / Right balance is largely a useless metric. There have been no studies indicating that a “balanced” pedal stroke is more beneficial than your “natural” one.

And the reality is that there is really no way to effectively correct said imbalance.


Go with actual power via a spider or dual sided. You will most likely immediately be asking why your trainer doesn’t match your power meter. I have two bikes with Cinch power meters, a Kickr, and a quarq. Used to have Vector 3 dual sided. I know I have a -2.5% different lower on my left leg and that gets worse depending on power level. If I did it again I would never go single sided because it creates doubt of its accuracy. Buy a used one so the price ends up the same as a single sided new one.

I’d recommend single sided.

I bought the dual sided Vector 3 pedals thinking I had an imbalance to sort out. Turns out I’m rarely more than +or-3% difference. The accuracy of dual sided is nice but not worth the opportunity cost IMO.

It sounds like a single sided will satisfy your needs…quantify your efforts, provide pacing feedback, and do so with consistency.

In retrospect, I’d rather have bought the single sided and spent the extra $500 on other kit.

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I have a mix of Quarq 2 sided and Stages one sided on various bikes. Both work great. The only issue I’ve had with the one side Stages was on my full suspension mountain bike. Because I descend with my left foot forward I get some occasional big power spikes. It throws off my 10 sec and below data for sprints in my records because these are all power spikes from descending.

This. I rarely hear what people are doing to train one leg to get from 48 to 50 % power. It’s generally non actionable data - but no shortage of claims how important it is to know.

I have dual sided Vector3s.

The only thing dual sided power meter showed me was that I don’t need a dual sided power meter.


Yeah, but the differences in power don‘t matter if you consistently use the same power meter for all your training and testing. Even if you have a strong imbalance, you can still use single-sided power meters for training and assessing your fitness — as long as the power imbalance stays consistent.

The only time when a single sided power meter will hamper your training is for single leg drills. (There are some power meters like Quark‘s DZero that accurately measure total power, and they are fine for that, too, I‘m just talking about true single-sided power meters like single-sided pedal-based power meters or 4iiii‘s or Stages left crank-based power meters.)

Power balance as a metric does not seem to give any actionable information at this point. So if your power balance is 48:52, it is not clear whether it actually would be advantageous to get you to 50:50, and how to achieve that.

If you are strapped for cash and you already own a Kickr Core, a single-sided power meter will be just fine. You might have to assess your power separately anyway, because for many people, indoor and outdoor FTPs can be markedly different. (I find I can still put out a few % more outdoors.)

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go here:

use code HOLIDAY20

buy dual sided for $130 or something off!

you’re welcome :wink:

ps: got it from dcrainmaker’s blog!