bikepro

I've had a G3/Zipp 101 wheel set for over a year now. It's had to find anything to complain about. There are a lot of new power meters on the market now and it has caused the prices to go down. I still prefer the wheel based systems -- Of course I don't have multiple wheel sets.

Campag4life

Well explained...thanks.

JakiChan

I keep thinking that over the winter I'll save up and get one, but it's confusing what my options are for my Ultegra 6700 bike. I like my wheels, so PowerTap is out and I'm not sold on Stages so I'm trying to figure out what else will fit. It seems complicated to me.

I also would be curious to find out how accurate the power meters on the spin bikes at my gym are. It might help me figure out if spin class is helping or not.

hueyhoolihan

a shoe based system might be popular, in that most people use the same shoes, regardless of wheelset, or crank. both shoes of course. maybe in the cleats or shoe soles.

and if shimano comes out with one i'm expecting royalties...

Gluteus

1st Hands-On Ride with Brim Brothers Zone Cleat Based Power Meter | DC Rainmaker

Weatherby

Anyone who rides a ubiquitous Specialized cannot possibly be a realy cyclist thingy. Just sayin kinda quickly

Bah Humbug

Beat me to it.

canam73

In my experience spin bike PMs are precise and consistent but not very accurate. They are fine to use to meter efforts and intervals as long as you don't try to equate the numbers to bicycle PMs like a PT or Quarq. Spin bike numbers will typically be much higher.

hueyhoolihan

an exhaustive review!

in the post, i was being a little silly, but apparently truth is at least EQUALLY as strange as fiction...

oh well, has anybody invented an LED light bulb yet? i've got some ideas.

Dunbar

That Brim Brothers review is 2 1/2 years old and they still haven't shipped. I think they're saying that they'll ship later this year but until then it's just vaporware.

DXchulo

Funny, I was entertaining the same idea. I'm coming off of a left leg injury, so bilateral power measurement matters to me. I'm not sold on Vector's durability as far as the pods go. I really want the Verve power meter and it's supposed to come out soon, but who knows?

Anyway, the different readings between the 2 PMs would make it impossible to determine whether your legs were imbalanced unless the imbalance was very large.

achoo

I don't. But some seem to think that using total power is "better" than just taking left power and doubling it. I was just pointing out that total power is really not any better than taking your left side power and doubling it. Total power doesn't tell you your left/right splits either.

Both total power and left power doubled give you a consistent number that can be used for training purposes. Since neither one gives left/right splits, I don't see how anyone can claim one is better than the other.

If you want true left/right power splits you need something that actually measure it. AFAIK that's just Garmin Vector at the moment. Power2Max claims to estimate it, and I have a teammate who uses one and it does give different left/right numbers.

Bah Humbug

This is the mistake you keep making. Total power is better than taking left-side power and doubling. That's because left-side power is not always a consistent fraction of total power. We don't care about the load on each leg; we care about the total load on the body. Doubling left-side does not give us that. Independent left/ right values do not give us anything demonstrably better than that. Having total power is an advantage. Having left/ right split is not.

DXchulo

Pioneer measures both sides. So does the Rotor 3D+.

Those are the ones you could buy today (can't buy Pioneer online as far as I know). More are on the way.

achoo

What mistake? That total power is no better than just left power doubled? You calling it a mistake doesn't make it so. I'd say you're under the obligation to tell us why total power with no idea of the underlying left/right balance is better.

Why? Total power doesn't measure any left/right split so you don't know if one's there or not.

You can't know that unless you measure left/right power. And once you measure left/right power, you're measuring left/right power and total power vs. left power doubled is a moot point.

And without measuring left/right power, you don't know that doubling left power isn't accurate enough. Sure, it varies. Some. But so does your body's ability to generate total power - that varies too. A LOT more than left/right power differences.

Why? Because you claim in the absence of measurements that left/right power balance varies?

You ain't measuring it. You can't know that.

Total power is no more useful a training tool than doubling left power. Even if there are variations in power balance, they're going to be smaller than the variations in your body's ability to generate total power - when you're fatigued or when you blow up both legs tend to be fatigued or O2 starved. When you have a good day, it's not limited to your left quad.

Doubled-left power data is every bit as useful data as total power. There's noise in both data sets. The fact is that the random noise introduced into the data sets from differences in the way left/right power is measured and summed into total power is unknown and indiscernible.

Yeah, there's noise in the data that's different. It may not even be random. But since you don't know what it is, and it doesn't impact the consistency of the output data, it's totally irrelevant.

furiousferret

I have the Vectors and fwiw, care about my l/r numbers. Due to an ankle surgery my left foot put out 8-10% less power than the right. Since I'm left dominant it should be the other way around. So when I look at my power numbers, a closer l/r ratio is important. For the average rider the ratios may not be important, but for injury recovery its a great marker.

My 2 cents, for the cost, Stages is a great product. However I'd probably go with a p/t for a tad bit more.

achoo

Is the Rotor 3D+ the same as the Power2Max? It sure seems to have a similar feature set, and Power2Max units all seem to be on Rotor cranks. Power2Max claims they estimate left/right balance:

power2max Features - power2max North America

The Pioneer units look interesting, but I do wonder about the accuracy of strain gauges zip-tied to crank arms. There's not much consistency from the manufacturer in THAT process... And the "special training" DCRainMaker mentions to install, using a special weight to calibrate it? Why would I want to pay $1500-$1800 for that?

achoo

Yeah, but think about this:

Even in your situation, with a known (injury caused?) power imbalance - what specifically would a PowerTap tell you about your left/right power balance that a Stages unit wouldn't?

Further, how would "limiting" yourself to a Stages unit instead of a PowerTap impact your training? I don't see how it would, even in your situation.

DXchulo

No, it's not the same. The Rotor 3D+ PM actually measures both sides. Rotor 3D+ Power Meter 30mm Crank 110BCD

As for Pioneer, those issues you mentioned are on the old version. There are no zip ties on the new version and I think they made installation a little bit easier. Pioneer Electronics launches new, improved power meter - VeloNews.com

RChung

Well, for one thing, you can do pretty precise drag estimation with total power but we haven't been able to get consistent results with drag estimation using power meters that double one-side power. There are other reasons but that's a pretty clear one since many riders who've been doing structured training for a few years have plateau'd on their training gains and if they want to get faster they have to pay more attention to drag reduction.

As for L/R balance and injury, I had a little sciatica problem a few years ago that resulted in a huge bilateral imbalance. My right foot flopped, I could only walk upstairs by taking a step with my left then dragging my right up, I couldn't push down with any force on the downstroke on that side, etc. -- and I had a PowerTap. Over the course of six months or maybe longer I just kept riding and eventually my (total) power crept back up to my previous level. I have no idea what my exact L/R balance was before or what it is now but I know that my total power is back up to pre-injury level. So, although I disagree with you that total power isn't more useful than doubling one-sided power, I'll agree with you that knowing L/R balance isn't more useful than not knowing it.

[Edit] Which is not to say that I don't think there's a place for the Stages. I think it can be a good gateway drug.

DXchulo

You just put a lot of words in his mouth. He never said PowerTap is better than Stages when it comes to left/right balance.

He didn't even say that a PowerTap is superior to Stages, just that he'd go for the PowerTap (if not for the surgery). There's a lot of personal preference involved when it comes to where you want your power meter.

achoo

I put no words in his mouth.

He posted he'd get a PowerTap over a Stages unit and I asked him what specifically would be better about the data he'd get from a PowerTap. N.B. he actually answered that.

DXchulo

You should probably read that post again.

"My 2 cents, for the cost, Stages is a great product. However I'd probably go with a p/t for a tad bit more."

That's all he said. Where does he say that the PowerTap gives better data, especially concerning L/R balance?

achoo

Drag reduction is going to help in going faster no matter how you measure power. Using total power does make the estimation of drag coefficients more accurate, but unless you're in a wind tunnel the variation in measuring outside is going to introduce huge errors in the results anyway.

And even if you assume some skew in power numbers from using left power doubled instead of total power such that the resulting numbers are less accurate, the relative drag test results are going to be the same - lower drag positions will still have lower estimated drag coefficients. There will just be another unknown fudge factor scaled into the results. As long as the power results are consistent, you'll get consistent results from drag estimation.

No, actually I think that knowing the L/R balance can be useful. But if you don't know what it is, I'm saying there's absolutely no practical difference in using total power vs. left power doubled for training.

achoo

If it doesn't give better data, assuming all else is equal why would anyone pay more for it?