Gravel Biking The Wiouwash Trail, Wisconsin – September 19th 2022

Gravel Biking the Wiouwash Trail starts from the public parking lot on Hwy S near the Bare Bones Brewery round trip to the Outagamie County line.

Wiouwash Trail September 19th, 2022

If you would like to see more Cykelstrom Bicycle Power Meter App videos please visit: @Cykelstrom on YouTube and remember to “Like” and “Subscribe to our channel.

Trail Pic

Wiouwash Trail Head
Wiouwash Trail Head in Hortonville, Wisconsin

Gravel Biking The Wiouwash Trail – Cykelstrom Accuracy

SensorsCrank Power Meter (Watts avg.)Cykelstrom (Watts avg.)Difference (Watts)Margin of Error (Watts)
External Speed and Cadence145.51113.42-32.09+/- 1.26
GPS Speed and External Cadence145.51106.89-38.62+/- 1.22
External Speed Only145.96119.17-26.79+/- 1.44
GPS Speed Only145.96111.32-34.63+/- 1.36
Table created using Bland-Altman Analysis using a 4iiii Precision Pro dual sided crank power meter as the standard with 95% confidence level.

Discussion of This Ride’s Results

The result’s from this ride show a bias which is higher than normal. Typically Cykelstrom is within ten percent of the crank power meter when riding gravel. In this case Cykelstrom was within twenty-two percent of the dual sided crank power meter. This may be acceptable for a mountain bike ride in rough terrain, however, I am not happy with this result on a gravel bike riding a rail trail.

So what went wrong?

If we take a look at the power distribution curves, we can see that the distributions are very similar in shape, however there is a large offset from the two data sets. In fact the offset is 32 Watts. Cykelstrom recorded data very similarly to the dual sided crank power meter, however, the offset was due to poor calibration of the app. It is very important to calibrate Cykelstrom with the rider sitting on the bike in a normal riding position on a flat and level surface.

Future Improvements

As the developer of the Cykelstrom App, I am always learning ways to make our app better. I am currently working on a new algorithm so our app will become self calibrating. Here is my call to action. If you would like to help participate in new versions of our app, please send me an E-mail and I will be happy to add you to our ride tester’s list. You will be able to shape the way Cykelstrom evolves and become the bicycle computer or power meter app you always wanted. Here is a link for your convenience: developer@cykelstrom.com

Gravel Biking The Wiouwash Trail September 19th, 2022

Importance of Calibration (The RED Dot)

A factor that is within a rider’s control to get an accurate calculated power estimate is to calibrate Cykelstrom on a flat and level surface before a ride. After you have securely mounted your smartphone on your bike, sit on the seat in your normal riding position and press the “Red Dot” on the face of the Cykelstrom App. You should see the grade percentage reset to near zero or level. Once calibrated, Cykelstrom will remember this initial position until you press the “Red Dot” again. Recalibration is not necessary unless you change the angle of your phone mount or change bikes.

To learn more about calibrating Cykelstrom please read the article “Setting Cykelstrom Up For The First Time.”

Validating Accuracy For Cykelstrom

Bland-Altman Analysis is a frequently applied technique to investigate the agreement between two methods of measuring the same thing. In this application we are measuring the instantaneous power of the cyclist using the Cykelstrom Bicycle Power Meter App (blue) and a single sided crank power meter (red) in the figure above.

The distribution of dots in the plot below represent the difference of the two measurement methods versus the average of the two measurement methods. If the dots are evenly distributed above and below the zero line there is no bias between the two measurements. In this ride, there is a 32.09 +/- 1.26 Watt bias. The smaller the bias and margin of error the better the two measurement methods agree with each other. We use Bland-Altman Analysis to validate the accuracy of the Cykelstrom Power Meter App. We are constantly tuning our calculated power estimate to be as accurate as possible across mountain, gravel and road bike designs.

Gravel Biking The Wiouwash Trail September 19th, 2022

The large bias demonstrated by the Bland-Altman Analysis was due to poor calibration. Properly calibrating the Cykelstrom App on a flat level surface will significantly reduce the large bias of the app compared to a dual sided crank power meter.

Strava Activity For Gravel Biking The Wiouwash Trail

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Elapsed Time Moving Time Distance Average Speed Max Speed Elevation Gain Calories Burned
01:43:21
hours
01:41:44
hours
25.15
mi.
14.84
mph
19.28
mph
173.56
ft.
816
kcal
Haanjo heart in Larsen for Stacey.

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The Cykelstrom Bicycle Power Meter App Is Exclusively Available On Google Play

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Cykelstrom Bicycle Power Meter App Download
cykelstrom scan QR code
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Cuyuna Country State Recreation Area Galloping Goose Trail – August 28th, 2022

Cuyuna Country State Recreation Area Galloping Goose Trail located in Ironton, Minnesota was a late summer get away mountain bike ride.

Cuyuna Country Galloping Goose Trail located in Ironton, Minnesota August 28th, 2022

If you would like to see more Cykelstrom Bicycle Power Meter App videos, please visit @Cykelstrom on YouTube and remember to “Like” and “Subscribe” to our channel.

Trail Pic

Cuyuna Country State Recreation Area
Stacey cruising a berm at Cuyuna Country State Recreation Area – Ironton, Minnesota

Cuyuna Country Galloping Goose Trail Cykelstrom Accuracy

The best accuracy is highlighted in bold.

SensorsCrank Power Meter (Watts avg.)Cykelstrom (Watts avg.)Difference (Watts)Margin of Error (Watts)
GPS Speed and External Cadence72.4088.6716.27+/- 3.05
GPS Speed Only72.40107.6833.70+/- 3.65
Table created using Bland-Altman Analysis using a 4iiii Precision Pro dual sided crank power meter as the standard with a 95% confidence level.

Cuyuna Country Galloping Goose Ride’s Results

This was the first visit for Stacey and me to the Cuyuna Country State Recreation Area Galloping Goose Trail. The bicycle for this ride was a Trek Top Fuel 8 full suspension cross country mountain bike with 100mm of travel. Galloping Goose is a flowy trail with many short punchy climbs. The power distribution of the Cykelstrom app shows a higher than normal frequency of low power observations when compared to the crank power meter. I suspect that the difference in the curves was due to higher than normal frequency of braking to keep a safe gap between Stacey and I while riding. The Cykelstrom data on average was within 22.4 percent of the single sided crank power meter which may be acceptable to most recreational rider’s on a trail like Galloping Goose.

cuyuna country galloping goose power distribution
Cuyuna Country State Recreation Area Galloping Goose Trail – August 28th, 2022

Validating Accuracy For Cykelstrom

Bland-Altman Analysis is a frequently applied technique to investigate the agreement between two methods of measuring the same thing. In this application we are measuring the instantaneous power of the cyclist using the Cykelstrom Bicycle Power Meter App (blue) and a single sided crank power meter (red) in the figure above.

The distribution of dots in the plot below represent the difference of the two measurement methods versus the average of the two measurement methods. If the dots are evenly distributed above and below the zero line there is no bias between the two measurements. In this ride, there is a 16.27 +/- 3.05 Watt bias. The smaller the bias and margin of error the better the two measurement methods agree with each other. We use Bland-Altman Analysis to validate the accuracy of the Cykelstrom Power Meter App. We are constantly tuning our calculated power estimate to be as accurate as possible across mountain, gravel and road bike designs.

Cuyuna Country State Recreation Area Galloping Goose Trail – August 28th, 2022

Importance of Calibration (The RED Dot)

The most important factor that is within a rider’s control to get an accurate calculated power estimate is to calibrate Cykelstrom on a flat and level surface before a ride. After you have securely mounted your smartphone on your bike, sit on the seat in your normal riding position and press the “Red Dot” on the face of the Cykelstrom App. You should see the grade percentage reset to near zero or level. Once calibrated, Cykelstrom will remember this initial position until you press the “Red Dot” again. Recalibration is not necessary unless you change the angle of your phone mount or change bikes.

To learn more about calibrating Cykelstrom please read the article “Setting Cykelstrom Up For The First Time.”

Strava Activity For Cuyuna Country Galloping Goose

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Elapsed Time Moving Time Distance Average Speed Max Speed Elevation Gain Calories Burned
01:06:06
hours
00:54:23
hours
6.97
mi.
7.69
mph
13.90
mph
312.01
ft.
627
kcal

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The Cykelstrom Bicycle Power Meter App Is Only Available On Google Play

bicycle power meter app download button
Cykelstrom Bicycle Power Meter App Download
cykelstrom scan QR code
Scan to go to Cykelstrom on Google Play

Biking Tracker – Cykelstrom Test Ride Oshkosh to Pickett and Waukau, Wisconsin – August 18th, 2022

As a biking tracker app, Cykelstrom, is used to record a rider’s performance while displaying information during the ride. The data from the biking tracker app is automatically uploaded to Strava.

If you would like to see more Cykelstrom Bicycle Power Meter App videos please visit: @Cykelstrom on YouTube and remember to “Like” and “Subscribe” to our channel.

Biking Tracker App Accuracy For This Ride

The best accuracy for this ride is highlighted in bold.

SensorsCrank Power Meter (Watts avg.)Cykelstrom (Watts avg.)Difference (Watts)Margin of Error (Watts)
External Speed and Cadence149.32154.09+4.77+/- 1.29
GPS Speed and External Cadence149.32149.31-0.01+/- 1.25
External Speed Only152.90163.59+10.70+/- 1.46
GPS Speed Only152.90158.07+5.17+/- 1.40
Table created using Bland-Altman Analysis using a 4iiii Precision Pro dual sided crank power meter as the standard with 95% confidence level.

Discussion Of This Ride’s Results

The most accurate results for this ride were when the internal GPS Speed data and an external cadence sensor were used. Since this ride was on the road and there was not much coasting, you can also observe that if we had no additional sensors that the results were fairly close to the crank power meter with an offset of +5.17 Watts +/- 1.40 Watts. The use of a cadence sensor is recommended, however if you are the type of rider which pedals continuously and does not coast for very long, the power measurement results may be acceptable.

For information on how to connect a Bluetooth cadence sensor to Cykelstrom please visit Adding Bluetooth Sensors To Cykelstrom.

The following graph is a power distribution that compares the biking tracker app, Cykelstrom, to a dual sided crank based power meter.

biking tracker comparison
Cykelstrom Bike Tracking Power Meter App (Blue) vs. 4iiii Precision Pro Dual Sided power meter (Red) on a Shimano 105 crankset
biking tracker comparison
Cykelstrom Bike Tracking Power Meter App (Blue) vs. 4iiii Precision Pro Dual Sided power meter (Red) on a Shimano 105 crankset

Cykelstrom As A Bike Tracker

As a biking tracker app the Cykelstrom Bicycle Power Meter App displays real time information while riding and records the position of each observation. At the end of the ride, Cykelstrom will upload your data to your Strava account automatically for further analysis. Your ride’s data file is also saved as a GPS Exchange Format (.gpx) file in your “Download” folder so you can upload it manually to any bike tracker program manually. For your convenience you can choose to save a comma separated value file (.csv) file so you can analyze your own data in the spreadsheet or fitness program of your choice. If you need help in uploading or importing your file please feel free to contact us at: support@cykelstrom.com

Strava Activity

Click on the map to visit this activity in Strava. Feel free to follow all of our test rides of the Cykelstrom biking tracker app.

Elapsed Time Moving Time Distance Average Speed Max Speed Elevation Gain Calories Burned
02:26:39
hours
02:20:44
hours
37.37
mi.
15.93
mph
27.32
mph
738.52
ft.
1,577
kcal
I haven't done this route in a while. App data was exceptional, so it was worth it.

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The Cykelstrom Biking Tracker App Is Only Available On Google Play

bicycle power meter app download button
Cykelstrom Bicycle Power Meter App Download
cykelstrom scan QR code
Scan to go to Cykelstrom on Google Play

Power Biking – Smartphone App Measures Cyclist’s Power

If you are interested in power biking and have a smartphone, you may be interested in observing your power output measured in watts. Smartphones typically have sensors that can be used to measure acceleration. Most smartphones also have a GPS receiver to determine your location and speed. Add some weather information and you have the makings of a power biking app.

Power Biking App Accuracy For This Ride

The best accuracy for this ride is highlighted in bold.

SensorsCrank Power Meter (Watts avg.)Cykelstrom (Watts avg.)Difference (Watts)Margin of Error (Watts)
External Speed and Cadence141.84142.380.53+/- 1.44
GPS Speed and External Cadence141.84139.71– 2.13+/- 1.62
External Speed Only142.96152.959.99+/- 1.67
GPS Speed Only142.96149.166.21+/- 1.41
Table created using Bland-Altman Analysis using a 4iiii Precision Pro dual sided crank power meter as the standard with 95% confidence level.

Discussion Of This Ride’s Results

This ride’s most accurate results are when external speed and external cadence sensors are used in conjunction with sensors internal to the smartphone. The smartphone used for this test ride was a Motorola G6 which has the Bosch BMI160 inertial measurement unit or IMU. I purchased this smartphone as a refurbished unit for around fifty dollars. The external cadence and speed sensors were purchased as a pair for around sixty dollars, however, you can find these sensors for a lot less. The cost of a typical power meter is easily five to ten times more expensive. The accuracy of a crank based power meter can be as good as +/- 1%, however, for me I am happy with accuracies +/- 10% and I like being able to move my smartphone to many different bikes.

The following graph is a power distribution that compares the biking power meter app, Cykelstrom, to a dual sided crank based power meter.

Power distribution comparison of Cykelstrom using and external speed and cadence sensor to a 4iiii Precision Pro dual sided crank power meter.

For an example of power distributions when riding a mountain bike please read Mountain Biking Hartman Creek State Park.

For a more detailed discussion of the power biking app and comparison to a crank power meter please read Power Distribution Comparison: Cykelstrom Bicycle Power Meter App vs. Crank Power Meter.

Strava Activity

Click on the map to visit this activity in Strava. Feel free to follow all of our test rides of the power biking app.

Elapsed Time Moving Time Distance Average Speed Max Speed Elevation Gain Calories Burned
01:42:42
hours
01:38:50
hours
25.38
mi.
15.41
mph
24.66
mph
448.16
ft.
1,037
kcal
Yesterday I felt the universe was conspiring against me by creating obstacles to prevent me from riding, i.e. flat tire, battery too low in the power meter, finally ready to ride and it starts raining…. So I listened and I didn't ride. Today, the universe was with me as it felt like I was riding a gravitational wave through the country. Never felt better or stronger. My app data was within .53 watts of the power meter +/- 1.4 watts. Pretty looking distribution curves and everything. Lesson learned: It pays to listen when the universe is speaking to you.

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The Cykelstrom Power Biking App Is Only Available On Google Play

bicycle power meter app download button
Cykelstrom Bicycle Power Meter App Download
cykelstrom scan QR code
Scan to go to Cykelstrom on Google Play

Bike Power Meters – Mountain Bike On Rural Road Using The Cykelstrom App

These are the results of a short test ride using the Cykelstrom Bicycle/Bike Power Meter App compared to a crank type power meter.

Mountain Bike Power Meter App Accuracy For This Ride

SensorsCrank Power Meter (Watts avg.)Cykelstrom (Watts avg.)Difference (Watts)Margin of Error (Watts)
External Speed and Cadence100.5494.38– 6.17+/- 2.95
GPS Speed and External Cadence100.5489.71– 10.83+/- 2.91
External Speed Only101.69100.18– 1.51+/- 3.20
GPS Speed Only101.6994.94– 6.75+/- 3.15
Table created using Bland-Altman Analysis using a 4iiii Precision Pro single sided crank power meter as the standard with 95% confidence level.

Discussion of This Ride’s Results

We decided to do a short ride after dinner as we were both recovering from the Wausau 24Hr Endurance Mountain Bike Race from the previous weekend. Using Cykelstrom during that race taught me a few things about my racing. To see the video and read about the race please visit Cykelstrom Mountain Bike Power Meter App Test Ride – Wausau 24.

Back to this ride’s results, we can see that out of all of the combinations of using external sensor to not using any external sensors that the worst case scenario is within 14% of the standard power meter for this ride. The best case scenario was within 5% of the standard power meter. The surface of the road was fairly smooth. The mountain bike used was a Trek Top Fuel 8 with the suspension locked. With the suspension locked there was still some movement of the suspension so it was not like riding a hard tail or road bike. I believe the results of this ride reflect the moving suspension.

Strava Activity

Click on the map to visit this activity in Strava. Feel free to follow all of our test rides of the Cykelstrom Bike Power Meter App.

Elapsed Time Moving Time Distance Average Speed Max Speed Elevation Gain Calories Burned
00:20:23
hours
00:19:45
hours
4.45
mi.
13.53
mph
18.02
mph
58.73
ft.
135
kcal
Stacey wanted to go for a short ride after dinner. It was 90+ degrees Fahrenheit today and humid, but when the sun went behind the clouds it was pleasant to be riding

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The Cykelstrom Bike/Bicycle Power Meter App Is Only Available On Google Play

bicycle power meter app download button
Cykelstrom Bicycle Power Meter App Download
cykelstrom scan QR code
Scan to go to Cykelstrom on Google Play

Cykelstrom Mountain Bike Power Meter App Test Ride – Wausau 24

With the Cykelstrom mountain bike power meter app revision 1.30 completed and tested on the local single track, it was time to give our app a test at the Wausau 24 endurance mountain biking race. I captured video of the first lap and included results for the first two laps of the race.

Video of the first lap of the Wausau 24 Endurance Mountain Bike Race

Mountain Bike Power Meter App Accuracy For Lap One

SensorsCrank Power Meter (Watts avg.)Cykelstrom (Watts avg.)Difference (Watts)Margin of Error (Watts)
External Speed and Cadence116.7123.87.1+/- 3.6
GPS Speed and External Cadence116.7101.5– 15.2+/- 3.4
External Speed Only119.2146.727.5+/- 4.2
GPS Speed Only119.2119.70.5+/- 3.9
Table created using Bland-Altman Analysis using a 4iiii Precision Pro single sided crank power meter as the standard with 95% confidence level.

Mountain Bike Power Meter App Accuracy For Lap Two

SensorsCrank Power Meter (Watts avg.)Cykelstrom (Watts avg.)Difference (Watts)Margin of Error (Watts)
External Speed and Cadence121.3141.520.2+/- 3.5
GPS Speed and External Cadence121.3109.1– 12.2+/- 3.3
External Speed Only122.8164.441.6+/- 4.0
GPS Speed Only122.8128.05.1+/- 3.8
Table created using Bland-Altman Analysis using a 4iiii Precision Pro single sided crank power meter as the standard with 95% confidence level.

Discussion Of This Ride’s Results

This test ride of Cykelstrom, demonstrates the challenges estimating power when riding in extreme conditions, like a heavy canopy.

During the ride, GPS reception was poor as indicated by the heading information using the magnetometer instead of GPS most of the time. Cykelstrom looks at the accuracy of the GPS heading information and will switch to the magnetometer if accuracy is low. It appears that since GPS accuracy was low, then other GPS derived data was not updated frequently enough to give good power estimates. For this reason, I recommend users of the Cykelstrom App use an external speed sensor and cadence sensor when GPS signals are unreliable. To learn how to add external Bluetooth sensors to Cykelstrom please visit Adding Bluetooth Sensors to Cykelstrom.

When using an external speed and cadence sensor, accuracy was greatly improved for this ride. The Cykelstrom mountain bike power meter app was within 6% at best and 17% at worst, on average, when compared to the standard crank power meter.

As the developer of Cykelstrom, I ride every opportunity possible to improve the app. Your suggestions and feedback are welcome at developer@cykelstrom.com.

Strava Activity

Click on the map to visit this activity in Strava. Feel free to follow all of our test rides of the Cykelstrom Bike Power Meter App. This is lap one of the Wausau 24 Race.

Elapsed Time Moving Time Distance Average Speed Max Speed Elevation Gain Calories Burned
01:30:13
hours
01:29:20
hours
10.82
mi.
7.27
mph
17.81
mph
682.74
ft.
894
kcal
First lap, started slow, caught back of pack in bottle necks anyway.

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The Cykelstrom Bike/Bicycle Power Meter App Is Only Available On Google Play

bicycle power meter app download button
Cykelstrom Bicycle Power Meter App Download
cykelstrom scan QR code
Scan to go to Cykelstrom on Google Play

Road Bike Power Meter – Test Ride West of Oshkosh, Wisconsin

Road bike power meter app test ride for Cykelstrom version 1.30 which is available to the public on the Google Play Store. Version 1.30 changes the app displayed averages at the end of the ride for moving time only. To make better use of the limited resources on some smartphones, improvements were made to GPS data collection threads and fine tuning of the power estimate calculations.

Road Bike Power Meter App Accuracy For This Ride

The best accuracy for this ride is highlighted in bold.

SensorsCrank Power Meter (Watts avg.)Cykelstrom (Watts avg.)Difference (Watts)Margin of Error (Watts)
External Speed and Cadence148.18154.706.53+/- 1.47
GPS Speed and External Cadence148.18150.462.28+/- 1.44
External Speed Only149.20162.6213.42+/- 1.63
GPS Speed Only149.20157.978.77+/- 1.66
Table created using Bland-Altman Analysis using a 4iiii Precision Pro dual sided crank power meter as the standard with 95% confidence level.

Discussion Of This Ride’s Results

This test ride of Cykelstrom, tests the accuracy of version 1.30. This version was created to improve the performance of the app on smartphones which are more limited in computing resources.

Highlighted in bold, the table shows that when using the GPS with an external cadence sensor presents results which are closest to the crank power meter. To learn how to set up a cadence sensor in Cykelstrom please visit Adding Bluetooth Sensors to Cykelstrom.

We continue to improve Cykelstrom to enhance your ride experience. If you have a question or comment please reach out to me at: developer@cykelstrom.com.

Kind regards, Chuck

Strava Activity

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Elapsed Time Moving Time Distance Average Speed Max Speed Elevation Gain Calories Burned
01:36:09
hours
01:35:00
hours
25.27
mi.
15.96
mph
23.37
mph
438.32
ft.
1,040
kcal
I made some updates to the power calculation algorithm, in addition I made the averages displayed at the end of the ride to represent only moving time. If you take a long water break, your down time is not represented in the averages.

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The Cykelstrom Road Bike Power Meter App Is Only Available On Google Play

bicycle power meter app download button
Cykelstrom Bicycle Power Meter App Download
cykelstrom scan QR code
Scan to go to Cykelstrom on Google Play

Mountain Bike Power Meter – Kettle Moraine State Forest Northern Unit – New Fane, Wisconsin

Cykelstrom is being used as a mountain bike power meter app in this ride demonstration.

Mountain Bike Power Meter App Accuracy For This Ride

The best accuracy for this ride is highlighted in bold.

SensorsCrank Power Meter (Watts avg.)Cykelstrom (Watts avg.)Difference (Watts)Margin of Error (Watts)
External Speed and Cadence128.11187.4759.35+/- 7.04
GPS Speed and External Cadence128.11145.7017.59+/- 5.64
External Speed Only129.25213.3384.08+/- 11.55
GPS Speed Only129.25162.4133.16+/- 6.27
Table created using Bland-Altman Analysis using a 4iiii Precision Pro single sided crank power meter as the standard with 95% confidence level.

Discussion Of The Mountain Bike Power Meter App’s Ride Results

Mountain biking presents more challenges in calculating power estimates of the rider on rough surfaces. Rapid changes in grade, roots, rocks, and direction, are challenges that do not exist when road biking. These challenges make estimating the cyclist’s power very difficult.

To address these challenges, I have introduced a new feature in the Cykelstrom Bicycle Power Meter App called “Mountain Bike Mode.” The new feature tunes the power estimate algorithm to more closely approximate the results of the single sided crank mountain bike power meter. Mountain bike mode is chosen under “Settings” in the Cykelstrom App. To learn how to change settings please visit Customizing Cykelstrom Through Settings.

Highlighted in bold, the table shows that when using the GPS with an external cadence sensor presents results which are closest to the crank power meter. To learn how to set up a cadence sensor in Cykelstrom please visit Adding Bluetooth Sensors to Cykelstrom.

Keep in mind that the forest canopy could be dense enough to block GPS reception, and in that case the addition of a speed sensor is suggested. For reasons which I am still investigating, I am finding that speed sensors when used in in rough terrain seem to overestimate the speed of the cyclist. I am experimenting with different technologies to try and determine why this is so. Accelerometer based speed sensors and magnet base speed sensor appear to agree with each other, but not agree with GPS speed. Calculating power estimates when using GPS speed agree more with the crank based power meter. So the saga continues and I will publish my thoughts as my ride testing continues.

Do you have any thoughts about this issue? If so please send an E-mail to: developer@cykestrom.com

Strava Activity

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Elapsed Time Moving Time Distance Average Speed Max Speed Elevation Gain Calories Burned
00:37:37
hours
00:37:37
hours
5.69
mi.
9.07
mph
17.05
mph
306.43
ft.
536
kcal

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The Cykelstrom Mountain Bike Power Meter App Is Only Available On Google Play

bicycle power meter app download button
Cykelstrom Bicycle Power Meter App Download
cykelstrom scan QR code
Scan to go to Cykelstrom on Google Play

Cycling Power Meter – Cykelstrom App Demonstration Ride West of Oshkosh, Wisconsin – June 21st, 2022

This video demonstrates the Cykelstrom Cycling Power Meter App for Android smartphones while riding on rural country roads in northeastern Wisconsin.

Accuracy For This Ride

The best accuracy for this ride is highlighted in bold.

SensorsCrank Power Meter (Watts avg.)Cykelstrom (Watts avg.)Difference (Watts)Margin of Error (Watts)
External Speed and Cadence134.59140.936.34+/- 1.57
GPS Speed and Cadence134.59137.252.66+/- 1.53
External Speed Only135.01148.9813.97+/- 1.74
GPS Speed Only135.01145.0510.04+/- 1.69
Table created using Bland-Altman Analysis using a 4iiii Precision Pro dual sided crank power meter as the standard with 95% confidence level.

Discussion Of This Ride’s Results

I am pleased with the results of this ride as it shows that the Cykelstrom Cycling Power Meter App is giving me consistent results when riding the same course repeatedly. Cykelstrom displays the best results when paired with an external cadence sensor. To learn how to configure a cadence or other sensors with Cykelstrom visit Adding Bluetooth Sensors to Cykelstrom.

Cycling Power Meter App Uses Smartphone Sensors

Most smartphones have sensors that measure motion. The sensor combination is called an inertial measurement unit or IMU. The IMU is composed of accelerometers and a gyroscope that provides information about the smartphone’s orientation relative to the Earth’s surface. In addition to the IMU, most smartphones have a magnetometer and global positioning system. The magnetometer provides compass like direction information. The global positioning system provides provides location, direction, and speed information. The smartphone may also have a data link to a weather information service. With information from the sensors, GPS, data link, some clever math and empirical evidence Cykelstrom estimates how much power the cyclist generates.

Strava Activity

Click on the map to visit this activity in Strava. Follow me on Strava to see more Cykelstrom Activities that were automatically uploaded. To learn how to configure Cykelstrom to automatically upload your rides visit Upload Your Ride Data to Strava.

Elapsed Time Moving Time Distance Average Speed Max Speed Elevation Gain Calories Burned
01:45:15
hours
01:43:04
hours
25.30
mi.
14.73
mph
24.54
mph
436.68
ft.
1,049
kcal
Another hot day!

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The Cykelstrom Cycling Power Meter App Is Only Available On Google Play

bicycle power meter app download button
Cykelstrom Bicycle Power Meter App Download
cykelstrom scan QR code
Scan to go to Cykelstrom on Google Play

Power Meter – Cykelstrom Bicycle Power Meter App – West of Oshkosh, Wisconsin – June 24th, 2022

The power meter capabilities of Cykelstrom help the cyclist understand where power is going during their ride. Cykelstrom calculates and displays the components of power due to wind, grade and rolling resistance.

Power Meter App Accuracy For This Ride

The best accuracy for this ride is highlighted in bold.

SensorsCrank Power Meter (Watts avg.)Cykelstrom (Watts avg.)Difference (Watts)Margin of Error (Watts)
External Speed and Cadence140.16148.358.19+/- 1.48
GPS Speed and External Cadence140.16145.054.89+/- 1.41
External Speed Only140.64156.308.19+/- 1.65
GPS Speed Only140.64152.8612.22+/- 1.56
Table created using Bland-Altman Analysis using a 4iiii Precision Pro dual sided crank power meter as the standard with 95% confidence level.

Discussion Of This Ride’s Results

I developed Cykelstrom for those who wanted to see their power data while riding, but did not have the resources to purchase an actual power meter. The accuracy of an app running on a smartphone is not better than an actual power meter, however we keep improving to get as close as possible. Every now and then a ride’s results just gets me excited to see that it is possible to be very close to an actual power meter’s performance. It is clear that for best performance, using the Cykelstrom in conjunction with an external cadence sensor provides the best results.

The cost of a cadence sensor is an order of one or two magnitudes cheaper than a power meter. Cykelstrom when set up and calibrated properly can give acceptable results and enhance the cyclist’s ride experience. To learn how to set up Cykelstrom please visit Setting Cykelstrom Up For The First Time. To learn how to add a cadence sensor or any Bluetooth sensor visit Adding Bluetooth Sensors to Cykelstrom.

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Elapsed Time Moving Time Distance Average Speed Max Speed Elevation Gain Calories Burned
01:40:43
hours
01:37:35
hours
25.30
mi.
15.56
mph
23.87
mph
437.01
ft.
1,054
kcal

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The Cykelstrom Power Meter App Is Only Available On Google Play

bicycle power meter app download button
Cykelstrom Bicycle Power Meter App Download
cykelstrom scan QR code
Scan to go to Cykelstrom on Google Play