You fool! That’s + or - 2%!!! One Eco will be 294, another 306! You’ll be in absolute agony over those 12w. Your friends will wonder why they never see the blue bike anymore. The blue bike will get fenders, bags, and a straight bar - all because you can’t bare the sight of 294wbilwit wrote: ↑Tue Nov 06, 2018 7:29 pmjust put the Eco on all your bikes, problem solvedneeb wrote: ↑Tue Nov 06, 2018 7:18 pmSure, but that was my point. 3w isn’t really significant but 6w is when measuring improvement or setting targets for intervals.northwestern wrote: ↑Tue Nov 06, 2018 6:49 pm1% of 300 ( assuming that's your FTP) is 3W. Not even the pros care about that.
P2M NG vs. NGeco - real-life accuracy difference?
Moderator: robbosmans
I think i remember when GCN visit Power2Max, they said the NG and NGeco 's hardware are built very much the same way.
Just that every piece of the NG got validated and fine calibrated out of factory. While the NGeco got randomly pick a few sample per batch to do quality check. Hence, they can't claim the same accuracy.
If that's true, most of the NGeco should be nearly as accurate as the NG. Except some few odd that might be off and didn't get caught because it wasn't sampled.
Just that every piece of the NG got validated and fine calibrated out of factory. While the NGeco got randomly pick a few sample per batch to do quality check. Hence, they can't claim the same accuracy.
If that's true, most of the NGeco should be nearly as accurate as the NG. Except some few odd that might be off and didn't get caught because it wasn't sampled.
One more thing which may be of some importance is that (at least in the EU) the NG models are backed by the 5 year warranty instead of 2 years for the NGeco. But as for accuracy, those +/- 2% are mostly extremes. Typical accuracy will be better than that and good enough for most of us mere mortals.
That's not what reading accuracy means. The "2%" should be read as "the true value lies within 2% of the vale that you read on the head unit with a given probability distribution". This means that if one gets a 300 W reading then the true value lies between 294 and 306 W, but please note that the probability distribution is usually very much centered around the true value. This means that you are much more likely to be within a watt or two from what's indicated.jfranci3 wrote: ↑Tue Nov 06, 2018 8:12 pmYou fool! That’s + or - 2%!!! One Eco will be 294, another 306! You’ll be in absolute agony over those 12w. Your friends will wonder why they never see the blue bike anymore. The blue bike will get fenders, bags, and a straight bar - all because you can’t bare the sight of 294wbilwit wrote: ↑Tue Nov 06, 2018 7:29 pmjust put the Eco on all your bikes, problem solvedneeb wrote: ↑Tue Nov 06, 2018 7:18 pmSure, but that was my point. 3w isn’t really significant but 6w is when measuring improvement or setting targets for intervals.northwestern wrote: ↑Tue Nov 06, 2018 6:49 pm1% of 300 ( assuming that's your FTP) is 3W. Not even the pros care about that.
As I mentioned earlier the second to second fluctuations are likely to be much higher. I never really bother to hold a steady power output during training and in fact this is counterproductive in most cases. Physiological adaptations do not happen suddenly when a given wattage is achieved - it's a continuous spectrum really, so if your average power over an interval is X, it doesn't really matter if you held the power constant ot fluctuated slightly (as long as those fluctuations are small enough).
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petromyzon
- Posts: 613
- Joined: Mon Apr 05, 2010 4:14 pm
LR balance etc. is bullshit. But better calibration and validation, and three extra years of warranty, are absolutely key. Worth it no contest.
You could sweat blood for another 10W on your FTP. I understand cro2's point about a likely normal distribution of error but even if you are a small handful of watts out it is relevant.
You could sweat blood for another 10W on your FTP. I understand cro2's point about a likely normal distribution of error but even if you are a small handful of watts out it is relevant.
Speaking of P2M, what's your opinion on Rotor's 24 vs 30mm spindle for it? I'm planning on upgrading to Power2Max and currently run Shimano's BB so getting 24mm would be easy, but I'm curious about your opinion. Getting NGeco, can't justify the price of NG.
I use the 24 mm version, so far so good. I haven't noticed any flexing even when putting 1400+ watts during sprints. The 30mm version is a slightly lighter and more expansive considering the price of the crank and the BB.
Why?
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TobinHatesYou
- Posts: 7018
- Joined: Mon Jul 24, 2017 12:02 pm
Oh I see. I keep L-R on my head unit, right under cadence. I find it interesting and it can help me keep proper technique on longer rides.TobinHatesYou wrote: ↑Wed Nov 07, 2018 8:29 amIn the context of spider-based PMs, it is bullshit / estimated / voodoo. I don't find it an amazing dataset with my Assiomas or Vector 3s, but it's fun to have.
I had a NG fail on me because the USB connector broke. P2max tried to claim I forced the cable in the wrong way - I have mechanical sympathy so find it hard to believe I would be so agressive or clumsy... Because of the number of hours of use between charging then it took me about 10months to discover the charge didn't work. It was literally only the 2nd time I must have tried to plug the cable in. The metal surround around the USB socket is flimsy and I don't think that help ensure the cable sits securely in the socket as it sits there vertically. I ended up replacing it for an NGeco - I now have two and they are both flawless. I used to have a Type S and that was also flawless. The 5yr warranty is pobably the main sell, but you could sell on a NGeco every 2 years and still be up. Never had the battery cover pop off or come loose and I have raced and ridden in foul conditions - but I wouldn't jetwash it.
In the relation to L-R balance the more interesting it would be to see how much inconsistency can be in the figures coming from single sided power meter-calculators.
