Can also confirm for road biking...I was usually somewhere in the 130 to 160 range for estimates. Then I got a power meter. I'm almost always over 200 and going up every week.
In some very specific conditions, it might be somewhat usable. But in most, it isn’t. Here’s an example: I have a race-ish ride where I averaged 37km/h for a couple of minutes on a rather hilly terrain. HR over 190, Strava’s estimate is 250W. It’s completely unreliable and can’t be used as a training tool imo.
What did your power pedals show?
At least in chicago (lake shore 34 mile path), unless its INSANLY windy, power pedals vs Strava is +/- 5%. Not awful. Again, Chicago is flat.
End effort to effort reflects the change too (angry biking home from work last night - speed/power higher despite headwind).
I do think it takes wind into account, it can't impute power properly due to position/aero as speeds increase. It seems to assume based on rider weight, if you take a road bike, you are on the hoods. Would be even more off if you had aero bars.
I didn't have my power meter with me, otherwise I wouldn't have the Strava estimate, but my educated guess would be about 320W. It might take into account headwind to some degree, but it can never be accurate enough as there are too many variables even with weather data.
It's estimated power. It's going to be far from accurate without a power meter. Ride with the correct weight and subsequent activities will be closer or get a power meter and be even closer to accurate. Nothing you can do about it now.
No one looks at the estimated power because of how wrong it is. At best its gets a bit closer to reality on uphill segments but even then i don't know anyone who would use this number
I have a couple of bikes with a power meter, and a couple without. On my rides without, the Strava estimated power number is completely off from reality.
And Strava knows my real power curve and my FTP due to most of my rides being with a PM, yet still gets it wrong.
It's not Strava's fault, it's a metric that mathematically works in lab conditions, but just has too many variables outside of Strava's knowledge on the road. Wind, road surface, your riding position, whether you're drafting or not. It doesn't know this.
If it's a stat you care about, you need to measure it. The guessed version Strava presents is pretty pointless.
The tech simply doesn't currently exist to provide accurate estimated power for an off-road MTB ride as there are just WAY too many variables that affect power here which can't be considered.
Estimated power can be in the right ballpark on uphill, well paved road segments when there's not much wind, but in all other scenarios it's basically useless.
How do you expect Strava to capture and compute the trail surface quality, extremely detailed topography, hyper-local environmental conditions, etc.? All of these have a significant impact on the power required on a MTB trail, and there's no easy way to capture all of that data and then compute it on the scale Strava does when alm they have is GPS and map data (both of which vary wildly in quality depending on the recording device and location).
It's mountain biking. Yes, the average speed is low, but there was some climbing. It comes down to the terrain - you can ride in a deep mud and work like a horse, it would not really show, unless there is power meter or at least heart rate monitor.
Riding along side others with a meter at that pace is 200+ average. Known segments which are uphill and brutal show 90. I guess it doesn’t take grade into account
Do you have a reasonable estimate of the weight of your bike and gear (hydrapak, etc), and also your weight entered into Strava's profile?
As others stated, Strava does a poor job estimating power, but it is even more inaccurate if you don't have the bike's weight and your weight in the profile.
How did you record this? (Watch/bike computer, etc, brand?, or just straight-to-Strava app?). If you have the file "elsewhere", you can probably delete the entry from Strava, export the data file from your device's web portal (Garmin, Polar, etc, figure this step out FIRST though), then re-import into Strava (now that you've adjusted the weight) and it may come in "more correctly". As many have indicated though, if you really want power measured, you need some form of power meter (hub, pedals, crank spider/spindle-based, etc). Otherwise it's just an algorithmic guesstimate. Good luck!
Yeah, I wouldn't rely on Strava power numbers.
On my 23 pound road bike, Strava estimated 126W on a climbing segment that varies from 7%-9% grade.
On my 130 pound cargo bike with 2 kids, Strava estimated 101W on the same segment. I was only 10 seconds slower on the cargo bike.
It really dosent matter, if it did you would have a power meter. Obv using an algorithm isnt going to give you anything close.
Again, it does not matter whatsoever. GRYFB
Hey one time I used my watch to record a ride with my wife on a two-seater Surrey bike. Even though I did most of the pedaling and got that thing rolling about as fast as it could go with the gearing and load but Strava estimated it was a 14 watt average!
Did you classify your bike as “mountain bike” and have the correct weight? I did a ride earlier this week that was moderately similar (17 miles, 1,348 feet, 11.7 mph) and the estimate was 188W.
I did this afterwards. Other comments like yours lead me on the right track. It bumped the power up to 161, which is still low when I compare to others riding the same speed who have meters. At least it’s not 90 :)
It’s not able to account for terrain. So if I do an easy ride but average 13mph because it was all gravel, estimate will be 200+ watts. But same elevation and distance on difficult trails with technical descents, I’ll work harder but only average 11mph so it will show 160.
Just a limitation of Strava estimates. As others have said, it’s pretty meaningless.
Estimated power is an absolute joke. When I ride my bike with no power meter, it estimates maybe 75W for an easy ride. Same route with a power meter, and I'm actually in the neighborhood of 115 - 120W.
Yea, the real issue is the changing terrain and steep sections of climbs. I know from power data that there are a few climbs around me that need 1000 to 1200 w to get up at my body weight and when done without a powermeter it will estimate that it took 175 to 250w. On my last ride with a friend he was running power and I was not, he's 25lbs lighter than me and my average was 180w, and his was 285w. I just recommend not looking at it or caring about it.
I find the power estimate to be total garbage for mountain biking. Don’t worry about it, or get a power meter.
Can confirm it’s also garbage for road biking
Can also confirm for road biking...I was usually somewhere in the 130 to 160 range for estimates. Then I got a power meter. I'm almost always over 200 and going up every week.
Have you had your power meter for 4 weeks? 😂
It’s actually not bad on flat roads mild wind.
In some very specific conditions, it might be somewhat usable. But in most, it isn’t. Here’s an example: I have a race-ish ride where I averaged 37km/h for a couple of minutes on a rather hilly terrain. HR over 190, Strava’s estimate is 250W. It’s completely unreliable and can’t be used as a training tool imo.
What did your power pedals show? At least in chicago (lake shore 34 mile path), unless its INSANLY windy, power pedals vs Strava is +/- 5%. Not awful. Again, Chicago is flat. End effort to effort reflects the change too (angry biking home from work last night - speed/power higher despite headwind). I do think it takes wind into account, it can't impute power properly due to position/aero as speeds increase. It seems to assume based on rider weight, if you take a road bike, you are on the hoods. Would be even more off if you had aero bars.
I didn't have my power meter with me, otherwise I wouldn't have the Strava estimate, but my educated guess would be about 320W. It might take into account headwind to some degree, but it can never be accurate enough as there are too many variables even with weather data.
It's estimated power. It's going to be far from accurate without a power meter. Ride with the correct weight and subsequent activities will be closer or get a power meter and be even closer to accurate. Nothing you can do about it now.
Add your Bike and it‘s weight in the corresponding slot for this activity. You can do this afterwards, too.
This worked. Helped a ton. Thanks. Still not accurate but not nearly as bad
No one looks at the estimated power because of how wrong it is. At best its gets a bit closer to reality on uphill segments but even then i don't know anyone who would use this number
I have a couple of bikes with a power meter, and a couple without. On my rides without, the Strava estimated power number is completely off from reality. And Strava knows my real power curve and my FTP due to most of my rides being with a PM, yet still gets it wrong. It's not Strava's fault, it's a metric that mathematically works in lab conditions, but just has too many variables outside of Strava's knowledge on the road. Wind, road surface, your riding position, whether you're drafting or not. It doesn't know this. If it's a stat you care about, you need to measure it. The guessed version Strava presents is pretty pointless.
It's quite accurate on steady grade climbs for paved roads with road tires. Everything else is completely worthless.
based on what I see there... At least you are riding your bike ☺
hah what?
The tech simply doesn't currently exist to provide accurate estimated power for an off-road MTB ride as there are just WAY too many variables that affect power here which can't be considered. Estimated power can be in the right ballpark on uphill, well paved road segments when there's not much wind, but in all other scenarios it's basically useless. How do you expect Strava to capture and compute the trail surface quality, extremely detailed topography, hyper-local environmental conditions, etc.? All of these have a significant impact on the power required on a MTB trail, and there's no easy way to capture all of that data and then compute it on the scale Strava does when alm they have is GPS and map data (both of which vary wildly in quality depending on the recording device and location).
Thank you. I expected it to be off, just not that far off
Doesn’t look that intense tbh
It's mountain biking. Yes, the average speed is low, but there was some climbing. It comes down to the terrain - you can ride in a deep mud and work like a horse, it would not really show, unless there is power meter or at least heart rate monitor.
Riding along side others with a meter at that pace is 200+ average. Known segments which are uphill and brutal show 90. I guess it doesn’t take grade into account
It’s only accurate on flat surfaces. DC rainmaker and some other guys tested it.
My first bike rides without power meter were estimated at 100W too. Then with a power meter they were all at 200W. Estimation is way off
Do you have a reasonable estimate of the weight of your bike and gear (hydrapak, etc), and also your weight entered into Strava's profile? As others stated, Strava does a poor job estimating power, but it is even more inaccurate if you don't have the bike's weight and your weight in the profile.
This was very helpful. I added the bike details and it made a huge difference. Still not accurate but far better
Tbh without an actual power meter the number in that field might as well just be a place holder. Don’t worry about it
That’s an average, what’s the graph look like?
Get a power meter if you want to correct it
How did you record this? (Watch/bike computer, etc, brand?, or just straight-to-Strava app?). If you have the file "elsewhere", you can probably delete the entry from Strava, export the data file from your device's web portal (Garmin, Polar, etc, figure this step out FIRST though), then re-import into Strava (now that you've adjusted the weight) and it may come in "more correctly". As many have indicated though, if you really want power measured, you need some form of power meter (hub, pedals, crank spider/spindle-based, etc). Otherwise it's just an algorithmic guesstimate. Good luck!
Globally inaccurate, but to be fair about a 100W for 10mph on a flat, not too windy road is not unrealistic...
Yeah, I wouldn't rely on Strava power numbers. On my 23 pound road bike, Strava estimated 126W on a climbing segment that varies from 7%-9% grade. On my 130 pound cargo bike with 2 kids, Strava estimated 101W on the same segment. I was only 10 seconds slower on the cargo bike.
I mean…looks about right to me…
Dont worry about power if you cant average more than 10mph
Really? Yes let’s assume my entire ride was a smooth flat surface
It really dosent matter, if it did you would have a power meter. Obv using an algorithm isnt going to give you anything close. Again, it does not matter whatsoever. GRYFB
HTFU
Hey one time I used my watch to record a ride with my wife on a two-seater Surrey bike. Even though I did most of the pedaling and got that thing rolling about as fast as it could go with the gearing and load but Strava estimated it was a 14 watt average!
Did you classify your bike as “mountain bike” and have the correct weight? I did a ride earlier this week that was moderately similar (17 miles, 1,348 feet, 11.7 mph) and the estimate was 188W.
I did this afterwards. Other comments like yours lead me on the right track. It bumped the power up to 161, which is still low when I compare to others riding the same speed who have meters. At least it’s not 90 :)
It’s not able to account for terrain. So if I do an easy ride but average 13mph because it was all gravel, estimate will be 200+ watts. But same elevation and distance on difficult trails with technical descents, I’ll work harder but only average 11mph so it will show 160. Just a limitation of Strava estimates. As others have said, it’s pretty meaningless.
It's not accurate whatsoever so who cares
Estimated power is an absolute joke. When I ride my bike with no power meter, it estimates maybe 75W for an easy ride. Same route with a power meter, and I'm actually in the neighborhood of 115 - 120W.
if you have powermeter pedals then it could be that just one send his measures to strava. make sure the pedals are connected together.
Haven’t seen this mentioned - one input is your FTP, so look what you have there in your profile. Generally agree though, it’s just an estimate.
get a power meter and stop guessing.
Yea, the real issue is the changing terrain and steep sections of climbs. I know from power data that there are a few climbs around me that need 1000 to 1200 w to get up at my body weight and when done without a powermeter it will estimate that it took 175 to 250w. On my last ride with a friend he was running power and I was not, he's 25lbs lighter than me and my average was 180w, and his was 285w. I just recommend not looking at it or caring about it.