bobwysiwyg

Being a bit generous to myself by posting this here.. but I've replaced an old fluid trainer that died with a KICKR Snap. After playing with the Wahoo Fitness App, modifying variables, I've discovered Strava and Wahoo don't agree on many data points. I'm assuming Strava takes the raw data and interprets independently and comes to its own conclusions. Any input on which is more likely accurate or closer to reality?

canklecat

I use both Strava and Wahoo Fitness for road and trainer rides. But I have only an old Cycleops trainer, no devices attached. I only use the app as a timer.

On road rides I mostly use Wahoo Fitness because it's been 99.99% reliable on my old iPhone 4s and newer Android phones. Then I upload the finished ride to Strava. There are differences in interpolated data but that's how Strava works. I've noticed the same differences when I've used other apps and uploaded to Strava -- Cyclemeter, several others. They all work out to about the same after uploading to Strava.

When I've used three apps simultaneously to record road rides -- Strava, Wahoo Fitness and Cyclemeter -- all three showed slight differences in distance, speed, time, etc. But when uploaded to Strava, all three worked out to be nearly identical. Close enough I no longer worry about it.

I suspect the differences may be due to things like auto-pause/resume timing. Some apps offer adjustable settings for auto-pause/resume, some don't.

Strava has been glitchy on the road several times with all my phones so I quit using it to record road rides. Several cyclist friends have experienced the same glitches with Strava. Not sure whether it's due to GPS sync errors or something else. I just stopped using Strava to record rides. Problem solved. Didn't lose a single ride in 2018 using Wahoo Fitness to record my rides, and uploading to Strava afterward.

mtbikerinpa

I have had multiple glitches with Strava through the years but they stopped when I switched to an Iphone 6s. My android products had wierd randomness issues, and I changed to the apple when it was given to me as a NIB gift.

Machka 

Strava and Strava don't necessarily agree. Rowan and I can cycle the same route at the same time, and come up with anywhere from 0.5 to 1 km difference.

Take an average.

srode1

What types of data are you finding differences on? I use Training Peaks, Golden Cheetah for analysis of my rides, and Strava differs on training load, Normalized Power as well as average power from the results I see on GC. GC and Training Peaks are pretty consistent.

bobwysiwyg

First let me say this is a curious question on my part, I'm nothing more than trying to exercise and stay fit. Sadly I'm also something of a gadget geek which also leads to some data geekiness.
The primary difference I noted was in "watts," Whahoo fitness seems to give me more credit than I suspect I deserve.

zacster

If you don't have a power meter, take the results with a grain of salt. If you do have a power meter, take the results with a grain of salt.

If you keep the setup constant, you can then compare results over time and this is all that really matters.

If you have a Kickr Snap, you need to make sure your tire is pumped to the same pressure each time and that the tire doesn't slip.

canklecat

Regarding power estimates in watts, I'm surprised to find they're reasonably close to reality. Strava, Elevate and other software seem to get pretty close to results from cyclists I know who do use power meters, and they're close to my age and size, riding the same routes in the same conditions.

But I'm still doubtful about power estimates on climbs and downhills. The software estimates claim I can do 300+ watts on downhills, even with tailwind assistance, while climbs fighting headwinds might rate 150 watts but feel much more exhausting.

There is one software tool that takes wind into account, but it hasn't gained much traction: Strava Segment Wind Analysis. If it caught on it would created weighted estimates factoring in tailwind assists and headwind hindrances. I'd consider that a good thing. All of my top tens are heavily tailwind assisted. With a weighted score a local woman pro cyclist would have the KOM, not just the QOM. Her top ten was into a headwind, while everyone else in the top ten including the KOM had the benefit of a tailwind on the same segment.

bobwysiwyg

Interesting reference to Strava Wind Analysis. How does it work after authorizing? Does it apply retroactively, how is it reflected in your ride data. Is it somehow accessing your local weather data, wind speed/direction, at the time of your ride?

canklecat

The last time I used that Strava Segment Wind Analysis tool the permissions gave it access to all of my Strava data, so it revealed interesting info on my entire Strava history.

It accesses archived weather data (presumably from NOAA, which is publicly accessible), GPS data from Strava, etc., to estimate the weighted efforts including the effects of headwinds and tailwinds. Very interesting stuff.

I hesitated to log in yesterday because the site showed it's unsecured http rather than https. Sometimes that's a temporary glitch that can affect any site, but I was reluctant to log in and give access to my Strava data until the wind app site is secured. I don't worry about sensitive info -- it's just Strava -- but don't want to risk spam or inadvertent access to my Facebook account.

I'm really not sure why that wind data app isn't more popular. Seems logical for Strava to incorporate it as a standard feature. Although I suspect massive butthurt would result when people's tailwind assisted KOMs were downgraded on a weighted relative effort scale.

bobwysiwyg

Thanks for the reply.