mission control, strava, power, etc. [warning: data!]

mschwett

Well-Known Member
Region
USA
since a recent thread which discussed the mission control app's interpretation of "time" as different from strava or other apps, i took a look at the data for todays ride a few different ways.

in the past i've compared ride data captured with mission control, rideWithGPS, and cyclemeter and found that there are predictable - and small - differences between the total distance and the exact definition of the route. GPS is imperfect, and has a limited sampling frequency. but those errors for most riding conditions are really quite small, a few percent, perhaps. elevational discrepancies are much greater.

but what happens if we use the SAME source data, captured only in mission control, but then processed and viewed in strava, or specialized's ride app, and compare it to the idealized map data from the RwGPS route planner?

here is the "data": remember - the ride was captured ONLY in mission control.

comparison.jpg



distance (black/white circles): strava's initial reading of the distance is the same as mission control, assuming there is some rounding going on. 43.15 vs 43.16, whereas "ride" displays that as 43.2. the recorded value is likely 43.15x, or the calculations between points are being done with different degrees of precision. hardly significant. strava's "correct distance" option shifts the distance down by .85 percent, quite a small amount. of note is that it's shifting in the opposite direction from the route planned on the map, a basemap which bears a very high resemblance to the route ridden, including small sections of driveways, pathways, the major roads, intersections, etc. if i had to explain the difference of 1.7 percent between the planned route and the distance traveled, i'd probably put it down to the centerline of the roads, the radiuses at turns, and the inflation pressure of the tires. why strava's correction increases the variance, i could not say.

time (not circled, oops.): this one is very easy to understand. strava and specialized "ride" both use the duration of the ride and a simple algorithm to determine "moving time." i only stopped twice on this entire ride, and both times i paused mission control. those two pauses totaled 34 seconds, and neither of them was long enough (since GPS tracks tend to float a bit when stopping) to trigger a "moving time" pause in strava or ride. i've observed this over and over again, a ride with no stops whatsoever has exactly the same duration, whereas a ride with stops will show increasing variation with the number and shortness of the stops. very long stops will show as stops in either platform.

elevation (blue circles): this one is all over, undoubtedly due to the quality of the elevational basemap used for corrections, the accuracy of the iphone's barometric altimeter, the sampling rate as we go up and down lots of little dips and rises, and the terrible accuracy of GPS elevation. of note, the strava figure and the RwGPS route plan figure are very close (1.96 percent!), leading one to believe they probably use the same underlying topographic model. i had to manually correct a few obvious errors in the elevation profile of the route plan where it spiked up or down for no reason.

power (green and orange circles): the values for average power (green) are in agreement between strava and ride, which makes sense since the total time is also in agreement. the "adjusted power" or "weighted power" obviously uses a slightly different calculation, with specialized's figure 4% higher.

calories (yellow circles): this one is a bit of a head scratcher. the only variable here would be the "efficiency" of the human body, which has been scientifically measured over and over again to be between 20 and 25 percent. mission control and strava are clearly using the same value here, with less than half a percent variance (possibly due to the extra 34 seconds strava thought i was riding hahaha). specialized's own "ride" app, however, seems to be doing something else entirely, which is curious since they obviously have the power data, and the app is made by the same company that makes mission control. clearly, a different intern wrote that code!!

so, all in all, a very high degree of consistency. when i log my ride data, i use the mission control distance, the strava elevation, the mission control calories, the mission control time, and the strava weighted power. i don't actually use ride unless i used the motor, in which case it's interesting to see when i used it and how much, which strava cannot show (since specialized doesn't put in the .fit file!)
 

BlackHand

Well-Known Member
Region
USA
City
Western WA
Do you classify your rides in Strava as bike or ebike? And have you noticed any difference in the weighted power if you've used both?

I ask because there's about a 20% difference on my Bosch bike between the Bosch SW and Strava. I've always attributed it to the Bosch not counting coasting time while Strava counts it as zero power, but I've also wondered if Strava might have different algorithms for bikes and ebikes.
 

mschwett

Well-Known Member
Region
USA
Do you classify your rides in Strava as bike or ebike? And have you noticed any difference in the weighted power if you've used both?

I ask because there's about a 20% difference on my Bosch bike between the Bosch SW and Strava. I've always attributed it to the Bosch not counting coasting time while Strava counts it as zero power, but I've also wondered if Strava might have different algorithms for bikes and ebikes.
it depends if i used the motor or not. for a ride like this one, with no assist at all, i classify it as bike. if i use the motor even a minute, i’ll leave mission controls “eBike” classification. i have never seen the power figures change, but of course all the segments and PRs and so on do.

i do think the “power meter” readings are slightly high when the motor is assisting. that may be the actual reality that the motor allows a higher speed and cadence which squeezes a bit more out of your legs, or it’s a quirk of the way the meter works. if i do the same climb at the same heart rate and state of motivation/energy/weather with some assist and not, the climb with assist seems about 5% stronger. i also suspect this is the source of people saying the meter isn’t accurate.
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Mazovia, Poland
Going on a ride mschwett now but I have bookmarked your post for reading later!

No, I've read it now (still 20 minutes to leave my flat).

Whether your input data come from Mission Control or Ride, these come from the TCU of your Creo. It is the same if you connect a Specialized Turbo e-bike to a GPS bike computer such as Garmin Edge or Wahoo ELEMNT. The only data that matters is the number of revolutions your rear wheel made during your ride.

With MC or Ride, the app reads the Wheel Circumference as embedded inside your Creo. That value might be correct or not. It will be alread wrong if your tyre inflation makes the WhC of your rear wheel different. Change the tyre width and the data will become garbage. You're lucky because your values match the reality pretty well.

With a GPS bike computer, you can calibrate the WhC against either GPS or a map. For me, only the ride map is a trustworthy source. It is because cyclists compare their efforts based on a route ridden not on measurement such as GPS or (potentially wrong) e-bike readout. In your study, anything related to your e-bike was taken from the e-bike and the number of the rear wheel revolutions was multiplied by the WhC do give the distance. However, it was off by 0.37 mile compared to Strava.

OK, all that is not very important. What is important is MC works OK for you but it is very wrong for my both e-bikes, while I get a perfect Strava match based on the number revolutions read from my Vado or Vado SL and multiplied by a calibrated Wheel Circumference in Wahoo ELEMNT.

Not that I really do not agree with you. MC works for you but it does not work for me.
 
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mschwett

Well-Known Member
Region
USA
Going on a ride mschwett now but I have bookmarked your post for reading later!

No, I've read it now (still 20 minutes to leave my flat).

Whether your input data come from Mission Control or Ride, these come from the TCU of your Creo. It is the same if you connect a Specialized Turbo e-bike to a GPS bike computer such as Garmin Edge or Wahoo ELEMNT. The only data that matters is the number of revolutions your rear wheel made during your ride.

With MC or Ride, the app reads the Wheel Circumference as embedded inside your Creo. That value might be correct or not. It will be alread wrong if your tyre inflation makes the WhC of your rear wheel different. Change the tyre width and the data will become garbage. You're lucky because your values match the reality pretty well.

With a GPS bike computer, you can calibrate the WhC against either GPS or a map. For me, only the ride map is a trustworthy source. It is because cyclists compare their efforts based on a route ridden not on measurement such as GPS or (potentially wrong) e-bike readout. In your study, anything related to your e-bike was taken from the e-bike and the number of the rear wheel revolutions was multiplied by the WhC do give the distance. However, it was off by 0.37 mile compared to Strava.

OK, all that is not very important. What is important is MC works OK for you but it is very wrong for my both e-bikes, while I get a perfect Strava match based on the number revolutions read from my Vado or Vado SL and multiplied by a calibrated Wheel Circumference in Wahoo ELEMNT.

Not that I really do not agree with you. MC works for you but it does not work for me.

@Stefan Mikes what happens if you have your LBS set the WhC to the same calculated/calibrated value that you use in your ELEMNT? or will they not do it because it's a s-pedelec?

remember also that mission control uses the phone's GPS and altimeter, so it *MAY* actually be processing the speed sensor data in some way or another. i've noted a few times that upon coming to a complete definitive stop (brakes on, feet on ground) the "speed" displayed by mission control bounces around a bit, suggesting the GPS reading is being integrated somehow... !?!?
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Mazovia, Poland
@Stefan Mikes what happens if you have your LBS set the WhC to the same calculated/calibrated value that you use in your ELEMNT? or will they not do it because it's a s-pedelec?
They are allowed to do it on my Vado SL. The point is, I don't want them to do it (a derestricted e-bike (g)).

I can remember how several Forum members were trying to find and set the proper WhC value with their Spesh e-bikes (@Marcela was trying the hardest). I eventually decided it is not even worthwhile to try.

emember also that mission control uses the phone's GPS and altimeter, so it *MAY* actually be processing the speed sensor data in some way or another. i've noted a few times that upon coming to a complete definitive stop (brakes on, feet on ground) the "speed" displayed by mission control bounces around a bit, suggesting the GPS reading is being integrated somehow... !?!?
Now that's becomes interesting!

Honestly: As I have all done and solved with my Wahoo for the Strava side, I'm not really concerned with MC anymore. You have proven that MC works OK for you, and perhaps it is not worthwhile to investigate the subject more?
 

kahn

Well-Known Member
Region
USA
City
northWET washington
The fact that my heart still beats, around 58-60, and I can still breathe is more than sufficient data for me. I really can't sweat the details. I track using three things - they come close enough and I was a govmint employee (city) for many years - so there you have it. As mentioned, elevation data is the most subject to bigger variations.
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Mazovia, Poland
The fact that my heart still beats, around 58-60, and I can still breathe is more than sufficient data for me. I really can't sweat the details. I track using three things - they come close enough and I was a govmint employee (city) for many years - so there you have it. As mentioned, elevation data is the most subject to bigger variations.
For me, ride and e-bike data are vital for battery use planning. That's why all my Strava rides have the bike ridden associated to the ride, and in case I used BLEvo on the ride, I copy the vital e-bike parameters there. Being: Battery consumption, average assistance %, and Wh/km value. Based on knowledge of similar rides, I could determine a single Vado battery would do for today's gravel group ride. I only overlooked two facts: a. The battery was only 95% charged; b. The riding mates were strong and fast. I really should have had a spare battery with me. Unfortunately, economizing on the battery made me the slowest rider!
 

ReedM

Member
Region
USA
City
Winthrop, Maine
@Stefan Mikes : Which of the available Mastermind TCD-W display statistics are sent to Strava at the end of a ride? How is that data formatted? What other data is sent to Strava? It looks like you also copy some BLEvo data to Strava. Without BLEvo, how would you get average assistance and Wh/km from the TCD_W data?
Could you please send me an image of what your Strava data looks like and how it is formatted?
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Mazovia, Poland
@Stefan Mikes : Which of the available Mastermind TCD-W display statistics are sent to Strava at the end of a ride? How is that data formatted? What other data is sent to Strava? It looks like you also copy some BLEvo data to Strava. Without BLEvo, how would you get average assistance and Wh/km from the TCD_W data?
Could you please send me an image of what your Strava data looks like and how it is formatted?
Reed,
As I do not own a Mastermind e-bike and don't use Mission Control for ride recording, I cannot answer your questions.
Sadly enough, BLEvo will not work with the Mastermind TCD-w (it's confirmed).
I need to check if my Wahoo ELEMNT Roam would work with Mastermind yet.
 

mschwett

Well-Known Member
Region
USA
i will let @Stefan Mikes answer re:blevo, but on a pre-mastermind bike, the mission control iPhone app is the most standard way to get rides into strava. it does not send any of the motor power or battery usage. said data IS stored on specialized’s cloud which saves your rides, but also not embedded in any exported data files as far as i can tell. since i’m not a blevo user, i often add the wH statistic from mission control to the strava notes for future reference.
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Mazovia, Poland
Please view the linked page. I tells me that Element devices can receive Mastermind info via ANT
Yeah but Wahoo doesn't know about the MasterMind e-bikes yet :)
I simply am not able to confirm it works.
It certainly works with the 2020 and 2021 electronics.
 

Nubnub

Active Member
Yeah but Wahoo doesn't know about the MasterMind e-bikes yet :)
I simply am not able to confirm it works.
It certainly works with the 2020 and 2021 electronics.
I recently demo'd a Vado 5.0 equipped with mastermind. I also brought along my garmin 130 plus to record the ride. The garmin automatically connected to the bike to display power and cadence. Since the connection is ant I suspect the Wahoo and other bike computers will work as well. Don't think Specialized would want to alienate potential customers who already are using other computers to log their data. OTOH Blevo connects thru bluetooth and that is probably where Specialized made sure it wouldn't run ;).
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Mazovia, Poland
I recently demo'd a Vado 5.0 equipped with mastermind. I also brought along my garmin 130 plus to record the ride. The garmin automatically connected to the bike to display power and cadence. Since the connection is ant I suspect the Wahoo and other bike computers will work as well. Don't think Specialized would want to alienate potential customers who already are using other computers to log their data. OTOH Blevo connects thru bluetooth and that is probably where Specialized made sure it wouldn't run ;).
That's a very useful information!