Jarrett2

I just got a new road bike and a Garmin Edge 1000. With the Edge came a heart monitor, speed sensor and cadence sensor; but it also allows connectivity for power meters. I'm curious to find out more about them. What they are useful for and what is a good one to start with.

At my LBS, I saw a couple that were integrated into the crank. I also saw that Garmin sells some pedals for it. They both seemed pretty expensive options. Are there less expensive ones to start with?

Thanks in advance.

CliftonGK1

Power meters are an expensive option no matter what route you go. The most popular still tend to be the hub and crank based options. Sometimes if you're lucky, you can find a racer looking to get rid of a PowerTap hub on CL because they're upgrading to the newest thing. The easiest option right now if you have a SRAM or Shimano crankset is a Stages (tm) NDS crankarm replacement. They run about $750, and only require swapping out the NDS arm and calibrating to your ANT+ device.
A PowerTap hub can be had for cheaper, but then you also have to figure in the cost of a rim, spokes, cassette, skewer, tube, tire, and build labor. All said and done, it's going to be more expensive and more of a pain in the butt.
I haven't worked with the pedal-based ones, but I assume they're about as simple and effective as the crankarm solution.

Power-based training is effective for athletes looking to maximize performance gains. You can learn a lot about your fitness by analyzing your power data over the course of a ride: Heart Rate vs. cadence vs. power output vs. speed will give you data on your hill climbing, sprinting, and endurance efficiency. Analysis of things like 10s, 30s, 60s, and 5 minute peak power output will give you a much more accurate picture of your fitness gains over time.

For the recreational cyclist with no race-day aspirations, training with a power meter is an expensive waste of time unless you just really like poring over numbers.

Drew Eckhardt 

Structured training without the issues (lag, can't quantify short hard efforts, drift over time, reading high for reasons unrelated to performance like heat) that go with heart rate.

You could also get one because it's cool and will give you an accurate Calorie count. I don't think that's any sillier than spending thousands of dollars on a new bike, over a thousand dollars on a wheel set, six hundred on a GPS bike computer, or up to a thousand to have enough attractive outfits for a week's worth of riding without doing laundry.

Provided it fits your budget there isn't anything wrong with that sort of thing - I run 2004-2006 Record components in shiny silver because the titanium hardware color coordinates with my frame, use 1997-2006 Record quick release skewers at $100 a set just because they look pretty, and tracked down a NOS example of my favorite 1990s jersey in a larger size which fit my belly.

A used Powertap for cost reasons. Could be just $200 in wired form with a little yellow computer. Functional but not sexy.

Otherwise good choices some where around $800 are:
- Powertap hub. One wheel, any crank, any pedals, swap to any 700C bike using rim brakes without tools.
- Power2Max spider based or Stages crank arm. One crank, any wheel, any pedals, swap with tools to other bikes
- Vector (one sided). Any crank, any wheel, one road pedal, swap to other bikes with tools.

If you switch between bikes with compact/standard/triple cranks you want a hub or pedals.
If you want to run different wheels for training and racing you want a crank or pedal based unit.
If you want to run SPDs for cross and other pedals for road you want a hub or crank meter.
If you want to switch cranks and wheels you want pedals (or the Brim Brothers cleat shim based setup which isn't shipping)

Power meters that measure power on both sides (crank spider, hub, two pedal set) will provide numbers more directly comparable with other power meters, and would be more accurate if your power balance changes.

stephtu

If you can wait a year there are various companies showing solutions at recent bike expos supposedly targeting the $500 price point. Time will tell whether these make it to market or are vaporware, if they meet their price target, and if they are accurate enough compared to existing products.

TrojanHorse

Stages is a good option and won't require new wheels or a whole new crank.

Power2Max looks interesting if your crank is already compatible.

iNewton is also intriguing. Lots of doubters out there but the results seem perfectly accurate. Of course, at that price you may as well get a strain gauge based meter.

PowerTap is a nice option too if you feel like either building up a new or buying a new rear wheel. Prices have plummeted in the last two years.

Jarrett2

Thanks I will do some more research into it.

IBOHUNT

I've had the PowerTap and now have the Stages solution. I have two bikes with the same crankset so it allows me to swap the cranks. Allows me to use different wheels as well.
The iBike Newton looks good but needs a firmware upgrade to allow indoor trainer use and another option to send the data to your Garmin

All told the iBike would cost me ~$750
Stages runs about the same

The recently shown at Interbike 4iiii $399 solution is similar to Stages in that it's a strain gauge attached to a crank but you attach it to your crank using epoxy. DC Rainmaker did a review

4iiii?s Introduces $399 Power Meter, Precision: My First Ride With It | DC Rainmaker

Another option to wait on is the Watteam PowerBeat which is both pedals for $499

4iiii?s Introduces $399 Power Meter, Precision: My First Ride With It | DC Rainmaker

Good luck

sstorkel

I'm sorry, but you're completely incorrect... In the past, I've paid little attention to my power meter. This year, I've given it some minimal attention. I haven't really done any structured training (ex: intervals), but just paid attention to which power zones I'm riding in and generally tried to push each workout to be a little bit more difficult than the last. Notice the difference in results?



Strava seems to think that I'm about twice as fit this year as in the four previous years and I definitely feel that out on the road. In the past, a 45-mile ride with 3000 feet of climbing would have been a killer. This year, that's an easy training ride and it's the 90-mile days at 15mph average with 6000-7000 feet of elevation gain that are the tough ones.

To the OP: You can find more information than you want about power meters at DC Rainmaker's review page. You might look specifically at his 2013 Power Meter Buyer's Guide.

I use a PowerTap power meter and it's still the one that I would recommend as an entry-level device. The PowerTap G3 Hub is a terrific value and, as DC Rainmaker says, "is the closest I get to ‘set it and forget it’ when it comes to power meters on the market today". Older units, like the PowerTap Pro+ hub that I use, can often be found on the used markets and are just as good (though much heavier) as the current units. Avoid used wired units; they won't work with your Garmin. If you keep an eye out, you can frequently find sales on new PowerTap wheels and wheel sets.

bbbean 

Or if you're serious about fitness and want to quantify your rides more accurately than you can with a HRM or just a speedometer, or if you want to pace yourself better on long rides, or if you're trying to lose weight and want accurate calorie counts, or if...

FWIW, I'm thrilled with my Stages. At half the price of the other options, it gives me all the info I need as a 1st year racer and to better maintain my weight and fitness. As others have pointed out, there are a couple of companies who plan to market similar systems in the $400-500 range next year. If you're not in a huge hurry, those might be an option. I'm certainly interested in another PM for my CX bike, and if one comes out in the $400-500 range, I'll be a customer.

Willbird

The kind of bad thing about the powertap for me anyway is the Bike I am getting first is a 9 speed with disk brakes, the next upgrade will probably be 11 speed 105 or even Taigra (coming) depending on how much I love the new ride whether I get 1 or two years out of it before I upgrade.

The 11 speed to 9 speed part (use an 11 speed hub now with a 9 speed rear setup) may just be a spacer ??...but the disk brakes and whether that would all translate over makes it more complex :-).

Decisions decisions :-).....I love data though, and wind is a factor that hoses a lot of the other data, the power meter in the wind brings back data that really means something :-).

Bill

chasm54

Well, he's not completely incorrect. I'm glad you are happy with your PM, but if you're not doing a structured training plan and are just paying attention to riding in zones, you'd probably have seen very similar results with just a HRM - and they're a lot cheaper.

Of course, lots of people like data. But if one isn't using it systematically that's all it is, just data.

bbeasley

Wow the times they are a changing.

<future conversation in BigBucks...er uh StarBucks>
I'll have a Triple, Venti, Soy, No Foam Latte and instead of change I'll take a power meter.
</end of BigBucks>

They're getting down to my cheap ass price range

IBOHUNT

Coffee should come two ways

1. Black
2. Hot

end of discussion

Speed costs money, simple as that.

I was rootin round in some pictures the other day and found one where I had averaged, wait for it....

wait.....

really, this is good.....

10.8 mph

Back to your regularly scheduled thread; sorry for the hijacking.

Willbird

the question is, did you puke afterwards ? If so,10.8 was #epic :-)

himespau 

Apparently, the Brim Brothers Zone is finally about to come out (I've heard ~$1000). More than I'd personally want to spend, but I love the idea of shoe-based powermeter if I was going to get one. Would work on any bike at any time. Just one, and you're good to go (assuming you don't also want to use it for mtb). As is, there are deals to be had on a use powertap, but you're locked into using a single wheel for whenever you want to do power.

IBOHUNT

Not that I recall. That didn't start happening till I started racing and training with a power meter. What a coincidence eh?

volosong

I've been using a Stages power meter since this riding season began. Sure wish I knew what those numbers mean. Even purchased several books off Amazon. Till I understand it all, it's just a 'toy'.

bbeasley

You've come a long way Sir Rik!

IBOHUNT

Feel free to PM and ask me; I'll help however I can.
The caveat is I've only been ridding as an adult for 3 years and I'm by no means a coach or understand it all but I can make sense of what the numbers tell me and how to use them. First and foremost is the FTP test. Without that it is just numbers.

sstorkel

I train systematically, I just don't bother with regimented workouts that require timing every movement down to the second nor hours of research/preparation/study beforehand. Would I get better results if I used the power meter for more regimented workouts? Probably! Do I care? Not really. I've already achieve results that most in this forum would kill for...

As far as heart-rate monitors, I've been using HRMs for far longer than the power meter and find that they're a relatively poor way to mesasure performance or effort. They're also entirely useless at predicting how many calories you've burned during exercise. When I got the PowerTap and realized just how far off my HRM had been with respect to calories burned, it made a dramatic change in my weight loss.

Willbird

I'm a little confused here about KJ of energy, I can find several conversion webpages that tell me 1542kJ is about 369 kilo calories.

Yet somebody else told me a kJ is roughly equiv to a "calorie".

I did a 124 minute, 31.5 mile ride at 15.2 average,219 feet elevation change, Strava said my average output was 203w, and I expended 1542kJ....Strava also says 1719 calories, which is insane. My weight for that ride was entered at 250 and I am actually 227, forgot to update that. It was a mostly zone 3 ride so average HR was 135.

Should also point out my bike is a 7200 multitrack with 700x35 tires, not a road bike.

Drew Eckhardt 

There are 4.2 kilojoules per Calorie (where 1 Calorie = 1000 calories).

However, cycling metabolic efficiency varies between 20 and 25% so 1kJj out is somewhere between 0.95 and 1.19 Calories burned.

If you assume the best efficiency you couldn't over-estimate Calories burned and 1 Calorie = 1 kj comes within 5% of that making it a useful rule of thumb, especially with a Powertap which is under-reporting by a few percent due to drivetrain losses.

Strava being wrong is a separate issue. Estimating power is easy where you're headed up-hill and nearly all your energy is going into lifting your known weight up the hill. On flat ground at low speeds rolling resistance can vary by a factor of 2, and at higher speeds aerodynamic drag (with power to overcome proportional to the cube of velocity, versus a linear relationship with rolling resistance) varies.

CharlyAlfaRomeo

I'm pretty sure I saw a Powertap disc brake hub coming for next season on DC Rainmaker's site.

Willbird

OK so it was the metabolic efficiency I was not properly factoring in then :-). My bathroom scale is the best "power meter" I have at present, and it credits me roughly with about 400 calories per hour of cycling.

Bill

Dunbar

It's roughly a 4:1 conversion from Kj to calories (i.e. multiply calories by 4 to get Kj.) Since humans are about 25% efficient it means to do 1542Kj of work you had to actually burn 4X that much energy in Kj's or 6168Kj. Divide that by 4 to get calories and you can see why many just use a 1:1 conversion.

As far as Strava kind of hard to say how accurate it is without a power meter.