Power Meter Selection.. HELP


I’m in between 2 power meters, the Pioneer DuraAce 9100 or the Rotor 2inPower.

Which one would you use and why?

Thanks for your feedback!

Ray has all the answers.

I don’t think he has updated since 2018, but not much changes in a year.


I know your question was very specific, however, I’ve used crank arm based power meters and have switched to Assioma Duo pedals as they are less expensive, just as (or more) accurate, lighter and easily swapped between my multiple bikes.


Between the two I would probably say the Rotor as it won’t be affected by the Shimano power meter inaccuracies as documented by gplama and others. That being said aesthetically DA cranks look nice

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Just a thought and a bit of a tangent but are you taking BB diameter compatability into account?

I know it wasn’t an option, but I can’t help to add that Quarq should be on everyone’s shopping list, especially the new models. And the Quarq w/ Dura-Ace chainrings is :drooling_face:


I’m a big fan of Rotor power meters. Full disclosure, I do sell them at my shop. But I have also been racing on, training on, and generally beating the crap out of mine for years and they still read consistently and smoothly. Not to mention that they don’t require regular zeroing, frequent battery charges, and have very, very low zero-offset drift. I finally killed my crankarm-based PM on my road bike and will be replacing it with a Rotor.

There are two go-to reviewers of power meters, @dcrainmaker and @gplama, and both are very active on this forum. I see someone has already linked to @dcrainmaker’s power meter buyers guide, which IMHO is the go-to article you should read.

Of the two, definitely get the Rotor! All power meters using Shimano’s latest Ultegra or DuraAce cranks that measure power on the right side are not accurate, because of their asymmetric design.

However, @dcrainmaker found that the Rotor is accurate outdoors, but had and may still have some accuracy issues indoors. Rotor’s new Quark-style power meter has not yet been reviewed by either @gplama or @dcrainmaker, so I do not know how that fares.

As already pointed out, you should consider a Quark power meter, which has received high praise from both, for accuracy and reliability. The only downside is that it measures only total power rather than left-right power. You will still be able to do single-leg drills, but you do not have accurate left-right power balance figures. Personally, I’d be totally fine with that.

I’ve just hit ‘go’ on this over on gplama.com too Cycling Power Meter Guide – GPLama.com

My quick rundown and a yes/no on every power meter I’ve used/tested/broken over the last few years. It’s still a work in progress, but most of the main ones are covered.


Awesome, thanks, that’ll be another default link in the future.

By the way, why did you use your “beloved” SRM power meter as the teaser photo? :grin:

Clickbait. :wink:


@GPLama Do you want to test my InfoCrank? I have one in Melbourne.

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I’ve had three Pioneer units over the years with no issues. The newer generation units are nicer than the older ones.

Pioneer )p(afaik) still doesn’t have any kind of phone app to change settings, so unless you plan to get one of their head units (or use a Wahoo), make sure you can do everything you want to do with your head unit of choice.

I guess with new BT ones you can use Pioneer Control app to control it. Not sure though.

I am also using Pioneer for years without any issue. I also have their head unit. while their head unit fantastic, their mobile app is still needs improvement but their website totally sucks. Even though you see all data you need to see, the design is from stone age.

If you want to consider something other than these two you mentioned then I can recommend Power 2 Max power meters. Can’t praise them enough. Ben using one myself for nearly a year now. I would buy one again without a moment of hesitation.

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+1 For the Assioma Uno/Duo.

  • Pedal based

  • Cheapest in the market AFAIK

  • Super reliable. Never had a dropout, never had a spike

  • Garmin Vectors were a nightmare

Bonus point:

This Sunday I crashed pretty bad on a descent and beat the **** out of my left pedal. When I saw the damage (the plastic was all scratched and chipped) I was freaking out… I thought I had lost a lot of money there. It turns out that the pedal still works like a charm (tested by sprinting many times and the values match my usual power). If you are worried about the aesthetic damage, the replacement will set you back just 59€ because there are no electronics inside the pedal body.

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