Buying a Crankset-Based Power Meter These Days
09-28-20, 11:10 AM
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09-28-20, 11:15 AM
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So, for various reasons, I'm in the market for a crankset-based, dual-sided, PM (Shimano compatible). I've looked for
I'm looking for dual power and Shimano compatible. The bike is a 2020 Domane (with the newer style BB).
Thanks!
- Pioneer - They shut down their op and sold to Shimano earlier this year apparently. ("out of stock. Discontinued")
- 4iiii - Every option is "out of stock"
- Stages - You guessed it; "out of stock"
- Shimano - I've heard there are some issues (from GP Llama specifically).
I'm looking for dual power and Shimano compatible. The bike is a 2020 Domane (with the newer style BB).
Thanks!
09-28-20, 11:33 AM
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Re: Stages dual side crank PM
I agree with all the information above. Aside from the studies showing the inaccuracy of the drive side due to the how Shimano designs their cranks....I have a buddy who was adamant on getting a dual, because he suffered from an injury that caused one leg to be weaker than the other. Guess how the R/L balance/TE/Smoothness helped? It didn't, and it didn't change the way he rides. He just replaces the batteries a lot sooner than I do on my non-drive side cranks.
Are you adverse to getting pedals like Assimoa? You have to use Look style cleats, but I've read nothing but good things about them.
I agree with all the information above. Aside from the studies showing the inaccuracy of the drive side due to the how Shimano designs their cranks....I have a buddy who was adamant on getting a dual, because he suffered from an injury that caused one leg to be weaker than the other. Guess how the R/L balance/TE/Smoothness helped? It didn't, and it didn't change the way he rides. He just replaces the batteries a lot sooner than I do on my non-drive side cranks.
Are you adverse to getting pedals like Assimoa? You have to use Look style cleats, but I've read nothing but good things about them.
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09-28-20, 11:41 AM
#29
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This is a good point. Presumably, riders with two legs would set progressive targets for the weak side and monitor progress.
Anecdotally, I’m a neurologist with a research background in neurorehabilitation and partial atrophy of the left quad from an old disc herniation. All I do is force myself to use that leg hard on the bike and in the gym and watch the bulk come slowly back over the years.
Anecdotally, I’m a neurologist with a research background in neurorehabilitation and partial atrophy of the left quad from an old disc herniation. All I do is force myself to use that leg hard on the bike and in the gym and watch the bulk come slowly back over the years.
[Edited to add:] As an aside, my friend doesn't pay attention to "pedaling dynamics" or "pedaling smoothness" metrics. He can't pedal circles -- he'd yank his prosthesis off if he tried pulling up. All he can do with his prosthetic leg is push down, so he pushes down hard. As I mentioned, he eventually surpassed his pre-injury FTP.
Last edited by RChung; 09-28-20 at 11:54 AM.
09-28-20, 11:47 AM
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It doesn't surprise me that they say that. However, I've worked with several riders who think drag measurement is important. I've had poor luck with getting precise measurements from single-sided power meters. When Team Sky/Ineos riders (who famously used Stages power meters during races) needed to do drag measurement on the track, they always switched to power meters that measured total power.
09-28-20, 01:42 PM
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Both I and my friend had several years of power data prior to our injuries. In both cases, we didn't really set progressive targets for the weak side; in both cases we just set targets for total power. It was easy to see that our total power had dropped, it was easy to see when it recovered. My friend eventually surpassed his pre-injury FTP though, admittedly, his sprint never recovered to his two-legged sprint. After the sciatica episode, I (evenutally) regained both my pre-injury FTP and pre-injury sprint; I can't say the same about the head trauma. I'm down a bit on both FTP and sprint, but I don't particularly blame bilateral asymmetry for that.
[Edited to add:] As an aside, my friend doesn't pay attention to "pedaling dynamics" or "pedaling smoothness" metrics. He can't pedal circles -- he'd yank his prosthesis off if he tried pulling up. All he can do with his prosthetic leg is push down, so he pushes down hard. As I mentioned, he eventually surpassed his pre-injury FTP.
[Edited to add:] As an aside, my friend doesn't pay attention to "pedaling dynamics" or "pedaling smoothness" metrics. He can't pedal circles -- he'd yank his prosthesis off if he tried pulling up. All he can do with his prosthetic leg is push down, so he pushes down hard. As I mentioned, he eventually surpassed his pre-injury FTP.
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09-28-20, 03:26 PM
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Oh come off it - the last three or so times you've replied to me were to ridicule me, so when you phrase the question like that I couldn't help but wonder what your intentions were. I didn't want to ignore you, but wasn't going to open myself up to another helping of that.
So it seems obvious - if my right leg is injured and I go from generally 49-51 to 55-45, then to believe I'm fully "recovered" I'd want to not only see my power return to normal, but to see my balance back to 49-51 as an indication that my left leg isn't just overcompensating. If you don't think that would work, well... I don't know what to tell you. It's what I'd do. but I don't care enough to use a true dual-sided PM.
So it seems obvious - if my right leg is injured and I go from generally 49-51 to 55-45, then to believe I'm fully "recovered" I'd want to not only see my power return to normal, but to see my balance back to 49-51 as an indication that my left leg isn't just overcompensating. If you don't think that would work, well... I don't know what to tell you. It's what I'd do. but I don't care enough to use a true dual-sided PM.
But in this case, I don't think I was doing that. I don't understand how one would use separate left/right information for rehab purposes. My daughter studies ballet, and she injured her right foot a couple of years ago. When she came out of the cast, her right leg was weaker but she just worked on it until she could dance as well as before, with right leg as with left. There is no power meter in ballet, yet her rehab has been pretty successful.
09-28-20, 03:51 PM
#34
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Rchung and Bah Humbug beefin' ! 
In the few posts I've made since joining ~1.5yr ago, I got my own taste with WhyFi....sometimes people just need to vent their real-life frustrations thru keyboard warrioring
On Topic: I did some basic research of my own on power meters and found that at the amateur/enthusiast level, it's more economical, as well as no-more beneficial to use dual-sided power. I also wanted to retain the use of my SPD-SL cleats. The choice was obvious: Stages gen3 r7k 105
In the few posts I've made since joining ~1.5yr ago, I got my own taste with WhyFi....sometimes people just need to vent their real-life frustrations thru keyboard warrioring
On Topic: I did some basic research of my own on power meters and found that at the amateur/enthusiast level, it's more economical, as well as no-more beneficial to use dual-sided power. I also wanted to retain the use of my SPD-SL cleats. The choice was obvious: Stages gen3 r7k 105
09-28-20, 03:53 PM
#35
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Hmmm. If you think I'm ridiculing you, it's very possible I'm guilty but, I assure you, if there's a pattern it's not intentional. You don't have a high enough profile in my mind to keep track of the things you write. So I suppose if it has happened repeatedly, each event was independent.
But in this case, I don't think I was doing that. I don't understand how one would use separate left/right information for rehab purposes. My daughter studies ballet, and she injured her right foot a couple of years ago. When she came out of the cast, her right leg was weaker but she just worked on it until she could dance as well as before, with right leg as with left. There is no power meter in ballet, yet her rehab has been pretty successful.
But in this case, I don't think I was doing that. I don't understand how one would use separate left/right information for rehab purposes. My daughter studies ballet, and she injured her right foot a couple of years ago. When she came out of the cast, her right leg was weaker but she just worked on it until she could dance as well as before, with right leg as with left. There is no power meter in ballet, yet her rehab has been pretty successful.
And here's the problem: you seem to be thinking I'm claiming balance is required for rehab (otherwise, a counterexample doesn't really mean anything), and that's not what I said. However, I can't help but feel like you're trying to set it up such that it looks like that is what I said, and then prove me wrong. Which is exactly what I was alluding to with my first reply, and why I dread seeing your name enter my quotes.
The bolded part doesn't really help, either.
09-28-20, 04:20 PM
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My legs will probably forever be unbalanced (lost the top half of my right fibula and had to have my LCL, hamstring, and gastrocnemius attachments moved as a result). Not sure what the imbalance is, but, as long as I have normal gait and am able to increase power, I'm good with seeing overall improvements. For Zwifting, a solo, left-side meter might make me appear faster.
09-29-20, 11:43 PM
#39
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my 7 years old Quarq riken is still going strong, kinda wish it would just die so i can save another 100g for a lighter crank
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09-30-20, 01:57 AM
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I have had, at one point, 5 Quarqs (one per bike) and am down to 3 now (well, 2 as I just sold one and am replacing it with a Power2Max for no reason other than FOMO). Quarqs batteries last a while and the damn things just work without issues. I am very happy with them - and side note, if you buy from Bicycle Doctor USA, you get very attractive rates on them. Everything I have read about P2M indicates that they work just as well.
I got me a Stages left side PM way back when they first came out, as a cheaper option for my rain bike. It gave me a power number that was WAY off, compared to the Quarqs on my other bike, and I ended up selling it off.
One interesting thing I just learned about the Quarqs - the newer DZero power meter spiders apparently DO fit the newer Red GXP cranks, if you dont want to go the DUB route. Their website doesnt say this, but Andrew from their customer service team confirmed it for me.
So I seem to have a nerve issue in my right leg that's been acting up (sports injury related). I do monitor my leg balance to see if there is a significant change that might indicate a worsening of things. It wont necessarily help me with rehab, but it can provide some info as to whether there is a change.
I got me a Stages left side PM way back when they first came out, as a cheaper option for my rain bike. It gave me a power number that was WAY off, compared to the Quarqs on my other bike, and I ended up selling it off.
One interesting thing I just learned about the Quarqs - the newer DZero power meter spiders apparently DO fit the newer Red GXP cranks, if you dont want to go the DUB route. Their website doesnt say this, but Andrew from their customer service team confirmed it for me.
I've never understood how one would use that information even if rehabbing from a serious injury. I've had to rehab from two semi-serious injuries over the years that I've had a (total power measuring) power meter and I'm not sure how that information would have helped. Can you explain? I also have a friend who had to have one leg amputated slightly above the knee. How could he have used specfiic sided information to aid his rehab?
Last edited by guadzilla; 09-30-20 at 02:11 AM.
09-30-20, 11:39 AM
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SMH Some of you guys squabble too much . . . some are over sensitive, some just like to squabble looking for street cred. I'd appreciate it if you'd stop messing up other's threads.
(I've got the names, I've made a list, consider this a preliminary warning.
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(I've got the names, I've made a list, consider this a preliminary warning.
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09-30-20, 02:18 PM
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I haven't posted in this thread, but can I get on the list? I just made parole and I could use all the street cred I can get.
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09-30-20, 02:34 PM
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I'll see all of you in the virtual parking lot!
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09-30-20, 04:46 PM
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09-30-20, 11:17 PM
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Me and my big ducking mouth. I couldnt just leave well alone, could I? So of course today my Quarq's battery ran out midway through my last FTP interval. First time it has happened in nearly 10 years of using the damned things.
10-01-20, 04:12 AM
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