Power Wattage

goonz

Morning

Quick one, was looking at Strava and my wattage is much lower than the guys around me but I am still faster than most, I got a 3rd overall today but my wattage was over 50W lower than the 1st place.

What does this mean exactly? And how accurate is it?

lc1981

I presume you don't have a power meter and you're referring to the power values that Strava generates? I'd take those with a pinch of salt, but presumably if you need less power than others, it's because you're lighter than them? Strava explain how it works here.

slowbike

lc1981 wrote:

I presume you don't have a power meter and you're referring the power values that Strava generates?

Ah yes - Strava Power !!

Relies on the weight of your kit too ...

I've found it remarkably constant on an individual basis - but of course, it cannot take into account the massive head/tail wind experienced during the ride.

goonz

lc1981 wrote:

I presume you don't have a power meter and you're referring to the power values that Strava generates? I'd take those with a pinch of salt, but presumably if you need less power than others, it's because you're lighter than them? Strava explain how it works here.

Is a power meter a good idea? Im not massively into knowing all that info but as its on Strava I just took an interest...

Grill

My PM wattage isn't even close to the Strava algorithm. Strava power = clownshoes

sloppyschleckonds

Data manipulation is rife on Strava, as others have said, its pretty much worthless.

Raffles

SloppySchleckonds wrote:

Data manipulation is rife on Strava, as others have said, its pretty much worthless.

Post cancelled...
Next abusive post and you're banned... take it as a warning...

sloppyschleckonds

Raffles wrote:

SloppySchleckonds wrote:

Data manipulation is rife on Strava, as others have said, its pretty much worthless.

as is every single post you make.

"

slowbike

Grill wrote:

My PM wattage isn't even close to the Strava algorithm. Strava power = clownshoes

Those that believe Strava Power equates to real power really do need to remember where Strava is getting it's data from and how it's calculated.

slowbike

SloppySchleckonds wrote:

Data manipulation is rife on Strava, as others have said, its pretty much worthless.

Oh I don't know - not completely - but you can't really compare with other ppls results if you have no knowledge of the accuracy of their input and different weather conditions will give you different results ..

For looking at your own results (as long as you take the weather into consideration) then you could take some value from rough averages.

imposter2.0

Raffles wrote:

SloppySchleckonds wrote:

Data manipulation is rife on Strava, as others have said, its pretty much worthless.

as is every single post you make.

irony

sloppyschleckonds

Raffles wrote:

Imposter wrote:

Raffles wrote:

SloppySchleckonds wrote:

Data manipulation is rife on Strava, as others have said, its pretty much worthless.

as is every single post you make.

irony

I coulda included you but couldnt be bothered remembering your name as I had coffee to sip

You could have left it at least 10 minutes before waiting to respond.

Anyway, getting back to the OP, add a couple of stone in weight to your Strava profile and the weight of your bike and see your power output increase.

declan1

Raffles wrote:

Imposter wrote:

Raffles wrote:

SloppySchleckonds wrote:

Data manipulation is rife on Strava, as others have said, its pretty much worthless.

as is every single post you make.

irony

I coulda included you but couldnt be bothered remembering your name as I had coffee to sip

That's two...

OT: I have no idea how accurate the Strava power meter is, but I highly doubt it's any good.

bigpikle

Strava power has very very little correlation to the actual power numbers from my PM. Best ignored really.

displacedaussie

SloppySchleckonds wrote:

Data manipulation is rife on Strava, I do it all the time.

GGBiker

Having used strava, powercal (power estimate based off rate of change of HR) and now powertap, they are all remarkably similar, within 10%.

My power curve from the powercal and the powertap are remarkably similar which surprised me, the value in the powertap is the certainty of knowing power output and having instantaneous values available.

edten

GGBiker wrote:

Having used strava, powercal (power estimate based off rate of change of HR) and now powertap, they are all remarkably similar, within 10%.

My power curve from the powercal and the powertap are remarkably similar which surprised me, the value in the powertap is the certainty of knowing power output and having instantaneous values available.

so for 300w, potentially out by only 30w, hmmm...pretty accurate then

lc1981

goonz wrote:

Is a power meter a good idea? Im not massively into knowing all that info but as its on Strava I just took an interest...

Given how expensive they are, I'd only buy one if I was really into knowing all that info!

GGBiker

edten wrote:

GGBiker wrote:

Having used strava, powercal (power estimate based off rate of change of HR) and now powertap, they are all remarkably similar, within 10%.

My power curve from the powercal and the powertap are remarkably similar which surprised me, the value in the powertap is the certainty of knowing power output and having instantaneous values available.

so for 300w, potentially out by only 30w, hmmm...pretty accurate then

Useful in that it is probably above most people's lactate threshold so doing their fitness a power of good!

Well paying anywhere from £500-£3000 for a power meter to reduce that accuracy to 2% is a hefty price to pay for most people and not really justifiable. On steady efforts like long climbs the accuracy of strava is even better due to the removal of wind resistance as a major factor in calculating.

There is a useful app/website called bike calculator which gives an extremely accurate power figure when I calculate it based on speed/incline/weight for climbs and TTs (with lowish wind speeds).


I enjoy the numbers/science side of cycling so can justify it that way. Some people have no interest. A guy who is regularly fastest in our club TTs rides purely on feel/perceived effort and it works for him. I like data and certainty, each to their own. Perhaps he would feel the same without his obvious natural talent!

Herbsman

Wind resistance isn't 'removed' on climbs. It's just that the steeper the climb, the greater the effect of gravitational resistance in proportion to the effect of wind resistance.

edten

GGBiker wrote:

edten wrote:

GGBiker wrote:

Having used strava, powercal (power estimate based off rate of change of HR) and now powertap, they are all remarkably similar, within 10%.

My power curve from the powercal and the powertap are remarkably similar which surprised me, the value in the powertap is the certainty of knowing power output and having instantaneous values available.

so for 300w, potentially out by only 30w, hmmm...pretty accurate then

Useful in that it is probably above most people's lactate threshold so doing their fitness a power of good!

Well paying anywhere from £500-£3000 for a power meter to reduce that accuracy to 2% is a hefty price to pay for most people and not really justifiable. On steady efforts like long climbs the accuracy of strava is even better due to the removal of wind resistance as a major factor in calculating.

The benefit of training with a powermeter is you can access the data whilst training and train in power zones. I don't think anyone buys a powermeter so they can dick wave on strava to an accuracy of 2%.

charlie_potatoes

Using the elevation correction button will help to make your strava stats a lot more consistent.
Given that a lot of people don't bother with it it makes comparison even more worthless.

jibberjim

edten wrote:

The benefit of training with a powermeter is you can access the data whilst training and train in power zones. I don't think anyone buys a powermeter so they can dick wave on strava to an accuracy of 2%.

Perhaps, but you assertion that it's "to train in power zones" is also not the only benefit or reason to buy a power meter - I ride with 2 PM's on my bike and have no interest in training by riding in a power zone.

NITR8s

Power wattage on strava does make me laugh, apparently on the below ride I hit 1000PW on two occasions.

http://app.strava.com/activities/51134578

Grill

http://app.strava.com/activities/50977495#908776680
I'm in 4th on that segment registering 116W average with my power meter. The guy in third needed 70 additional Strava watts to best me by 1 second. Strava power serves no purpose.

lc1981

Grill wrote:

http://app.strava.com/activities/50977495#908776680
I'm in 4th on that segment registering 116W average with my power meter. The guy in third needed 70 additional Strava watts to best me by 1 second. Strava power serves no purpose.

Maybe he's overweight?

Grill

Not according to his picture.

Pretty much all segments I do with my PM look like that.

Herbsman

WTF is this so-called 'power wattage' you keep going on about? Isn't that a tautology?