globecanvas

It's as good as estimate as anything else.

globecanvas

Typically extensive DC Rainmaker review of the new Powertap P1 pedal power meter.

PowerTap P1 Power Meter Pedals In-Depth Review | DC Rainmaker

He likes them, especially compared to the Garmin pedals. Highlights are that they are very easy to install, and use AAA batteries. He specifically calls out the battery form factor as a smart choice given how CR2032 battery doors are a typical failure point for Quarqs and Stages.

It's kind of crazy how many power meter choices there are at the moment.

Here's a quote that caught my eye, apropos of long running conversation here. Note that he's talking solely about accuracy, not reliability.

"In general, most power meters on the market today are very good when it comes to accuracy. I don’t subscribe to the ‘gold standard’ theory of certain brands. That’s outdated thinking, and ignores the fact that any and every power meter on the market can eventually have a ‘bad day’ given the right (or wrong) circumstances. Given enough time with so many units, I’ve got bad-day example instances on virtually every power meter (yes, including SRM). The trick is knowing what conditions might lead to this, and minimizing those."

Heathpack 

Its very tempting I will admit. I could solve my power issues on both bikes for under $1000. Over twice that for just one (new) SRM and I'm not sure I'm going to realistically get a used SRM that will work for me on my timeframe.

And dare I say it? My fitter likes them, he says they actually work.

revchuck 

I got my PM6 (wireless) SRM for $875, and it had been recently calibrated. Still, it wouldn't swap between bikes as easily.

Heathpack 

I am not completely up on all the nuances of the varieties of SRM units but it seems like every time I look into a used one, it doesn't work for me.

I do almost all of my intervals in the dark (before dawn), so I need a unit that will connect to my Garmin (my PC7 has no backlight).

I need 165 mm cranks which are less common on the used market. I can get new cranks for around $300ish but only if they can be had for the unit (as I understand it SRM either needs to install the cranks or I need to get them from SRM). It's not possible to get 165mm cranks for some of these older units.

And the SRM is for the TT bike. The chainrings that I'd like to put on the unit can't go on to some of the models.

Id like it to be Shimano or Rotor so I can swap between bikes.

Plus there's the total package cost when you're looking at swapping out cranks and chain rings. And the amount of time you spend searching sites for a used unit and then checking out all the details which you're fuzzy on anyway.

So it seems like there's a lot of units out there but when I investigate not too many work for me. I need a solution semi-soon though, so that does not help matters.

nemeseri

First of all, this thread is awesome. I'm half way through it and it has great info! Thanks.
My Pioneer PM arrived last week and I had a century ride on the weekend. I'm going to do a 20min test and a MAP test soon, but until then I'd like to see a rough estimation of my FTP based on the century. So two questions:

1) At 22 miles in, we had a steady long climb (avg grade 5%) and I decided to push it real hard with an intention to get an FTP estimate at the end. The climb took 17m 30s, I think I emptied everything, but I pushed the first 22 miles quite hard and I had two shorter climbs in my legs (~10-13 min total).
Do you think I can use the result as an FTP? Should I still get the 95% of it (because it was shorter than 20 mins)?

2) I'm pretty sure I won't be able to achieve this number on the flat course I plan to test regularly (even properly rested). How do you guys manage this issue? Do you use different zones for hill repeats and flat courses? Do I get the same stimulation if I set up the zones based on the flat results?

Thanks

wens

If you rode 22 miles hard ish, tempo?, then did anything approaching ftp for 17:30, and didn't want to climb off your bike and chuck it in a ditch for the next five or ten minutes, you didn't go hard enough. What are you planning to do with the power meter? What analysis software are you going to use? My first inclination is to give you the standard response around here to do a 20 minute test with nothing before it in the ride but a good warm up, and no plans after but to limp home.

That said, I have a coach and he hadn't had me do an ftp test since February, so depending on how you're going to train, it might not matter.

nemeseri

I just want to prepare for some racing next year and use it for training. I will start with simple plans based on power, so I know I need a proper test soon.
I plan to use golden cheetah and/or training peaks.

I was just curious about FTP, to set up zones, try them during my commute before the test. And yes, I rode in tempo, then rested for 5 mins during a long descent before the long climb. Just on the top there was a rest stop, I didn't fall off my bike, but the effort was very-very close to max.

shovelhd

If you could go 100% for 17 minutes and ride another 60 miles, you didn't go 100%. Probably not even 90%. If you have never raced, your RPE meter isn't calibrated for racing, where going 100% is mandatory but has to be managed. This will come with time and experience. I will also say that doing a test on flat ground is harder than on a steady grade. The hill provides an erg type effect that flat ground doesn't. It's harder to maintain steady power as the flat road undulates.

Do your test. In the meantime go ahead and set up your zones using your ride data. If you start doing intervals and you are not challenged to complete them, then bump the zone up until the test. If you are challenged by your intervals then you are in the ballpark.

furiousferret

Seems like a good product, and I'm tempted to get one. His criticism with the Vectors match mine. (not that its a bad pm per se, but has flaws). Regardless its looking more like the future of PM's is going to go pedal based.

gsteinb

when you go to 100 the tip of your nose cramps with the lactic acid

shovelhd

My ears emit smoke.

grolby

Good way of putting it.

On road, perhaps. I was out in the woods on my cross bike the other day and I hit my pedals on so many rocks. So. Many. Rocks. Maybe that's something that can be compensated for, but squeezing a power meter into a mountain pedal still seems like a tough task when I see how chunky the current pedal-based power meters are. The limited compatibility is a sticking point, too.

nemeseri

I really hope you are right, since the climb wattage was far-far better than expected.
(BTW I cramped 20 min later after the rest and suffered badly during the remaining 60 miles. YES, it was a dumb idea.)
Last thing: do you guys have a different power zones for hills? Do you learn to process the same wattage on flat? How do you handle this issue? Do you simply test on climbs? Put it differently: what is better? Over or underestimate slightly?

tetonrider

i think the 'bad day' notion is confusing. some brands (and some models within a brand) have 'bad days' more frequently than others. while any electronic product, esp one on a bike, can fail, history is pretty clear on the various brands.

conflating a 'bad day' with day-in, day-out accuracy is wrong, IMO.

EVERY new meter has had growing pains (=more failures at the outset than later on). that's why i, personally, am cautious about being a tester. at least with the brands that have been around for a bit longer we can more accurately evaluate the pros and shortcomings of the offering. i think new products sometimes benefit from wishful thinking on the part of the consumer (i've been there), but sometimes that consumer is left holding the bag.

when a power meter is $300, i see this as less of an issue. at $1500--for me--things change.

also, what DCR ignores is that basically all the companies came along and started using the "2% accuracy" claim of SRM--just copied blindly...who is going to verify it?

turns out that SRMs were all coming in at better than 1.5% accuracy with some models ~1% (due to improvements in manufacturing over the years--benefit of a couple decades of refinement), but in typical SRM fashion they never bothered to update things/advertise that. so silly. they did change, eventually.

none of this really matters to most people as they just accept the claims and then choose the meter that seems like it is going to meet their use case (cost, ease of a wheel change, fear of a crank change, stuff like that).

it is good that consumers have more options these days.

Doge

Does anyone know of software/where I get HR/Watt graph? I'm fiddling a bit with fit and would like to see if over longer term there is any change in the effort/power based on fit.

carpediemracing 

I was trying to do 4 x 5m VO2Max intervals, target 230-260w (based on my spring era 217-248w goal range, added 12-13w). I was struggling to hold 250w, and most of my efforts were in the 235w range. On the fourth one I pretty much gave up, recovered for about 30 seconds, then did (because I was on Zwift) a "hard" effort to the KOM line. Ended up doing about 400-425w for 40? seconds. My average for the 5m was 234w. My other intervals were 236w (eased for a bit then kept going), 238w (ditto), and 252w (went all the way).

Question is if I do a 400w effort at the end of the 5 minutes, am I defeating the purpose of the VO2 Max interval?

globecanvas

I don't know about "defeating the purpose," but I don't think doing 2 minutes Z5, resting, then 40 seconds Z6 is probably not training vo2max particularly. It's all about time in zone. For me, I know that 2-2.5 minutes is a sort of get-over-the-hump barrier for vo2max. If I'm going to quit the interval, I quit it before 3 minutes. If I get to 3 minutes, I am fully in vo2max and can usually stick it out to 4, 5, 6 minutes. The thing is that vo2max hurts and the easiest time to quit is right when it starts to hurt. But the hurting is the point.

I feel like whatever vo2max is, that system doesn't engage until you get through that barrier, and training is all about maximizing time in zone after getting through it. At least that's how I mentally try to get myself through the intervals, by thinking I have to get past the barrier because that's the whole point of the interval.

globecanvas

It's kind of crazy how many options there are! Feels like we are definitely entering a buyer's-market phase. Either prices are going to continue to drop, or else a lot of these products are going to get discontinued for lack of sales. Or both.

Ygduf

I feel like both is the answer to this. Some will flounder, but prices will continue to fall.

tetonrider

agreed. i am hopeful that prices will continue down, down, down. haven't fully seen that yet, but there has been some change.

i do hope that the inferior products will disappear, but that will never happen completely. someone will always line up to try the new new thing and there will always be marketing that attempts to convince consumers that there is no difference.

i think as and if quality products start to come down in price, then there is less margin and market for inferior products that might have sacrificed (consciously or not) on quality (accuracy, reliability, service, etc.).

i don't think we're too far off from power becoming ubiquitous. hell, my wife knows her power from spin classes (even though it is a bit of a joke; i rode alongside her the other day and we talked about calorie burn rates--had to break the news that actual energy expenditure was nowhere close to what was being reported elsewhere to her).

there will always be a cheaper option that comes along and insists it is the same as all the others, only less $.

mike868y

i'm considering getting a powermeter over the winter again. stages is attractive because of the pricing. quarq would be out of my price range unless i got a good deal on a used one (and i'm picky about my cranksets). also looking at the new crank based powerap and really hoping you add it to shimano cranks if you already own the crank.

tetonrider

did you know you can add a pioneer to existing shimano cranks? i just learned they will modify your crankset. your LBS can order a kit through a wholesaler to send in so they will do the upgrade.

kind of neat.

personally, i'd wait until some longer-term reviews are out on the PT meter, but that's me being gun-shy on new meters and reliability/performance. i'd rather not be a paid beta tester.

may not apply to this release, but too much history in this arena with companies, even established ones, going in and forcing consumers to be left holding the bag. agree on the PT's appeal, though.

mike868y

pioneer is cost prohibitive too. while i agree regarding being a beta tester for powertap, their hubs have historically been very reliable, no? actually, how much are PT hubs, maybe I'll just get my training wheels rebuilt...

misterwaterfall

I think that's where I'm headed. Everything I've read says it's an awesome piece, and the pricing is pretty attractive.