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Pedal Power Meters

I want a power meter - don't we all?!?!

Problem is...I have had my right hip replaced twice and my left knee replaced once. As a result of the surgery, I don't think my legs will be knocking out an equal amount of power. So I think I need dual pedals and the ones I think I want are Favero Assioma Duo.

I currently have a Lezyne Macro GPS head unit (Y10). Can anybody tell me if my head unit, which is not ANT+ enabled, will accept data from both pedals? I don't want to spend a lump of cash to find out I have to buy a new head unit, too. If my Macro won't do it, does anybody have any recommendations on an alternative head unit? My budget would be (reluctantly) up to £200.

Thanks to anybody that responds!


  • whyamiherewhyamihere Posts: 7,274
    It should work. The Assiomas can transmit the power from both pedals over Bluetooth. See the last line of G080 here:
  • mahydaddomahydaddo Posts: 5
    Thanks whyamihere. I read the same and thought the same so I sent an email to Lezyne and they said it wouldn't work and I would need to get a head unit with ANT+. So I am now well and truly!
  • redvisionredvision Posts: 2,545
    edited 19 June
    Like most power meters, they are compatible with any ant+ head unit. Some features such as pedal dynamics etc may not be available, but the main info fields should be - up to 6 power meter data fields according to Lezynes marketing blurb.
  • fenixfenix Posts: 5,290
    Unless you're racing - do you really need a power meter ?
    I've one on the bike on the turbo for training to power level but out on the road I don't need one.
    A turbo with power meter built in would be more beneficial for improvement.
  • pippi_langsamer-2pippi_langsamer-2 Posts: 1,257
    Undoubtedly, you will have imbalances in your leg power outputs, but realistically, what are you going to do about it? It's an expensive route to take just for curiosity's sake IMO. I found this few years ago- leg length discrepancy means one leg does output more the other. We know pretty much almost everyone doesn't have a 50/50 balance but certain physiological things make that imbalance worse. I bought a dual sided crank PM and this kind of proved what I already knew, but then......... so what?
  • aberdeen_luneaberdeen_lune Posts: 528
    They are great for knowing how many calories you’ve burned on a ride.
  • arlowoodarlowood Posts: 2,405

    They are great for knowing how many calories you’ve burned on a ride.

    Most if not all GPS computers will give you a calorie consumption figure. They figure will be a ball-park one based on average speed and duration rather than watts. But how accurate do you need the calorie burn figure to be.

    From what the OP says in his original post, I'm guessing he's not at the pro or semi pro level where calories and nutrition are critical to maintaining good condition and energy output.
  • aberdeen_luneaberdeen_lune Posts: 528
    They are great for monitoring your fatigue/freshness, and for establishing your power curve.

    Accuracy on calories burned is quite important you know. Calorific burn based on heart rate has always been wildly inaccurate for me.
  • mahydaddomahydaddo Posts: 5
    I'm 52 and stopped cycling when I was 25. I started cycling again in May last year because of a COPD diagnosis. I was also 3 stone overweight. I am not bothered about calories - I ride about 600 miles a month which dropped to about 400 in winter. It's now 600+. The calories take care of themselves. I am bothered about efficiency and currently use a heart rate monitor which is useful but not as useful as a power meter.

    I am nowhere near pro or semi-pro (and have no aspirations at my age) but cycling has become almost obsessive. I usually ride by myself so only have the numbers as company!
  • mahydaddomahydaddo Posts: 5
    Thanks, redvision.
  • super_davosuper_davo Posts: 525
    You dont necessarily need double sided even with a leg imbalance.

    Power meter values will quote +- 1% etc. accuracy but that is with themselves; they can vary much more from one PM to another. For example I know my 4iii PM reads significantly lower than my Elite Direto because I've run them together (more than 10% difference). Thats not a problem for me because I know that I can sustain 220 watts on the 4iii same as I can sustain 250 on the Direto. A lot of people I know with multiple power meters say the same; when I hear boasts like "I did 330 watts normalised" I take them with a pinch of salt.

    Same principle applies with leg imbalances. If you have a 60/40 imbalance and you're measuring the weaker leg; your figures will underread or vice versa if the stronger leg - but they will be consistent. You get the main benefits of a PM which is knowing how hard you are working so you can gauge your effort vs what you know you can do in order to get the most out of yourself. You won't be able to confidently say "I did more watts than you" vs anyone else but as per my example above I don't think many people truly can anyway.

    You can get a 4iii for £220ish which is a well respected, reliable PM, and as it does Bluetooth LE should already be compatible with your Lezyne (was hard to find anything definitive on the subject). If you get it and find it is not, then its really how much you want to spend. Probably not much point in getting anything more than a Wahoo Element Bolt or Garmin Edge 530 which both come in well under £200 and would be signficant upgrades on your Lezyne.

    I'll leave the minefield over whether you need a PM or not to others....
  • mahydaddomahydaddo Posts: 5
    super_davo, an interesting perspective. I'll have to work that through in my head but it appears to be right. Not bothered about the readings relative to anyone else. If I do a 3 hour ride with an average bpm of say 140, can I ride it better/faster? Currently, I think, "well, I will have to ensure that my average bpm is more than 140." For all sorts of reasons it doesn't quite work like that with a heart rate monitor but that problem would be negated with a power meter...I think!
  • wongataawongataa Posts: 855
    mahydaddo said:

    I want a power meter - don't we all?!?!

    Problem is...I have had my right hip replaced twice and my left knee replaced once. As a result of the surgery, I don't think my legs will be knocking out an equal amount of power. So I think I need dual pedals and the ones I think I want are Favero Assioma Duo.

    Crank spider power meters like the Power2max ones measure total power. You don't need pedal power meters to measure total power. I have a Power2max power meter and it just works.

  • fenixfenix Posts: 5,290
    Good point. A power tap hub would also do the same.
  • aberdeen_luneaberdeen_lune Posts: 528
    I disagree on the leg imbalance being consistent. I am left leg dominant on the flat then right leg dominant on climbs. Well that is according to my old Garmin Vectors and my Assiomos.

    I also have a P2M crank based power meter and it just works. Very reliable. The Assiomos are also great, very reliable.

    I agree with the point on different power meters reading differently. Can be 20 watts different at times.

    I have 3 different power meters. I don’t need them as I’m just an old guy who likes to keep fit and enjoys riding bikes. If I had to lose 2 of them and have only 1 I would ditch my two crank based power meters and keep the Favero Assiomo dual pedals. They are so easy to swap between bikes.
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