# Wahoo/Strava discrepancy?



## skhan007 (May 18, 2012)

I've been noticing that when I do a ride, my Wahoo data looks to be quite accurate, but when I upload to Strava, it states that I've done a lot less miles and a lot lower pace. For example, I went out for a quick 26 miler on my local multi-use trail, starting a mile marker 20 and turning around and returning at mile marker 33. 

After uploading the Wahoo data to Strava, the Strava data short changed me 5 miles and 2 MPH on my average speed. Does this happen with you guys? Is this something I email Strava about?


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## Srode (Aug 19, 2012)

I don't get robbed miles or speed but have seen my course off the road noticeably some times which is due to loss of satellite signal for the GPS, but I don't use Wahoo, I have a Garmin. I also have a speed sensor thought so if you don't that may be a difference. Strava can explain what happened from looking at your ride data if you contact them, they have been very helpful the couple times I have contacted them with questions.


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## Peter P. (Dec 30, 2006)

What makes you think it's Wahoo that's the problem and not Strava?


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## skhan007 (May 18, 2012)

Peter P. said:


> What makes you think it's Wahoo that's the problem and not Strava?


Who said Wahoo was the problem?


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## spdntrxi (Jul 25, 2013)

phone GPS is not as good as ..for example Garmin GPS... so that's what can happen.


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## dmarsey1 (Oct 5, 2013)

Rode with a friend today, I with a Garmin 500 he with strava on the iPhone. His showed the same exact distance but showed 300' more of climbing. Going to go with the Garmin as being more accurate.


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## Srode (Aug 19, 2012)

I've found the Garmin 500 consistently shows more elevation gain than an iPhone based on my 500 and the iphone Strava ride reports from several friends that use them. The 510 shows climbing closer to the iphone with the most up to date firmware installed. Zero difference in mileage with any of these.


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## Peter P. (Dec 30, 2006)

skhan007 said:


> Who said Wahoo was the problem?


Thanks for pointing that out; I had it backwards.

So what makes you think it's Strava that's giving you wrong numbers?


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## scottma (May 18, 2012)

Elevation gain with a Garmin is measured by the Garmin barometric sensor. An iphone has no such capability. If you record a ride with a smartphone, Strava uses static geographical data for elevation. They will be different.


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## looigi (Nov 24, 2010)

spdntrxi said:


> phone GPS is not as good as ..for example Garmin GPS... so that's what can happen.


Incorrect. Current phone GPS is every bit as good and in many cases better than that in Garmin cycling computers.


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## spdntrxi (Jul 25, 2013)

^ nah.. I"ll take my 810 and 1000 over the iPhone every time in terms of accuracy and precision.


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## scottma (May 18, 2012)

looigi said:


> Incorrect. Current phone GPS is every bit as good and in many cases better than that in Garmin cycling computers.


I have a few friends that use iphones and Strava. If I zoom into their rides, the track is "squiggly" compared to a ride recorded with a Garmin.


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## BikeLayne (Apr 4, 2014)

The other day I was riding with my son and my G-500 said the temperature was 98 degrees and my son's G-510 said it was 83 degrees. We were riding side by side out in the hills. I think the actual temperature was somewhere in between. However the elevation I read seems to agree with what STRAVA posts up. I do not know if the speed is accurate or not. Maybe I will take my Garmin and my Son's Garmin on a ride and see how they agree or not as the case may be.


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## scottma (May 18, 2012)

BikeLayne said:


> The other day I was riding with my son and my G-500 said the temperature was 98 degrees and my son's G-510 said it was 83 degrees. We were riding side by side out in the hills. I think the actual temperature was somewhere in between. However the elevation I read seems to agree with what STRAVA posts up. I do not know if the speed is accurate or not. Maybe I will take my Garmin and my Son's Garmin on a ride and see how they agree or not as the case may be.


The temperature reading is poo on the Garmins. Elevation will vary sometimes substantially from one Garmin to the next. It will agree very closely with what is on Strava since Strava uses the elevation data that your Garmin uploads.


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## Typetwelve (Jul 1, 2012)

scottma said:


> Elevation gain with a Garmin is measured by the Garmin barometric sensor. An iphone has no such capability. If you record a ride with a smartphone, Strava uses static geographical data for elevation. They will be different.


My Garmin 500 lists larger elevation gains than my iPhone. When I first got a Garmin, I ran it and my iPhone 5s at the same time...the elevation amounts were different by quite a bit.

I rode a 75 mile set last summer and all I had was an iPhone 5...my cousin ran his Garmin 500. My elevation total was 2514', his was 2968'...so yeah, +400' is a bit of a difference.


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## scottma (May 18, 2012)

A ride I go on has a bridge over a river. The Strava geographical data apparently doesnt realize there is a bridge there. My friends iphone ride shows him plunging down an embankment and shooting up a steep wall, and mine shows a flat stretch.


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## CrankyMinion (May 26, 2014)

Strava doesn't use the data from the speed sensor to calculate distance while Wahoo does. If I use Strava to record my session on rollers, it will show no distance. Wahoo will record the distance correctly even though the route plot is kinda slightly scattered about the same spot. If your wheel diameter is off in Wahoo, I can see discrepancy from there.


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## skhan007 (May 18, 2012)

Peter P. said:


> Thanks for pointing that out; I had it backwards.
> 
> So what makes you think it's Strava that's giving you wrong numbers?


I started at mile marker 20, went to mile marker 33, turned around and returned. That should be 26 miles. The Wahoo app stated 26 miles. Then, I uploaded to Strava at the end of the ride. Strava shows 20 point something miles. Way, way off. By over 5 miles. 

Doesn't Strava use the data collected from Wahoo? I don't have Strava running/recording during my ride, but rather, I upload the Wahoo data after the ride is over. 

I sent an email about this to Strava. I hope they have a solution. I love Strava, but cannot see using it if it's off by 20% on my mileage. Note, this mileage/speed discrepancy has occurred on several rides.


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## CrankyMinion (May 26, 2014)

All the data would be in the file I think, it's just Strava uses the GPS coordinates to calculate distance while Wahoo uses the data from the wheel sensor. I compare my records between the two and they are consistently off by about 1% in distance.


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## skhan007 (May 18, 2012)

CrankyMinion said:


> All the data would be in the file I think, it's just Strava uses the GPS coordinates to calculate distance while Wahoo uses the data from the wheel sensor. I compare my records between the two and they are consistently off by about 1% in distance.


1% I could live with. 20%? No way. 

Again, I'm not using Strava during the ride, but uploading the Wahoo data after the ride. Why would there be such a difference by just uploading to Strava? That's what I'm trying to figure out.


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## CrankyMinion (May 26, 2014)

If the wheel circumference is not entered correctly and Wahoo is indeed calculating distance from the wheel sensor only then that's where the discrepancy came from. When you upload your file to Strava, when calculating the distance, Strava uses your GPS location and ignores the reading from your wheel sensor. Unless you are 100% confident on your wheel circumference setting, the Strava distance is probably more accurate since it is map based. It could be something else of course but the wheel circumference will be the first thing I check.


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## skhan007 (May 18, 2012)

Where can I adjust the wheel circumference? I've been looking at the app and also tried google to figure out how to check on this. Any ideas?



CrankyMinion said:


> If the wheel circumference is not entered correctly and Wahoo is indeed calculating distance from the wheel sensor only then that's where the discrepancy came from. When you upload your file to Strava, when calculating the distance, Strava uses your GPS location and ignores the reading from your wheel sensor. Unless you are 100% confident on your wheel circumference setting, the Strava distance is probably more accurate since it is map based. It could be something else of course but the wheel circumference will be the first thing I check.


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## CrankyMinion (May 26, 2014)

Launch the Wahoo app, click on "sensors" at the bottom left corner, it should give you a list of sensors that you have connected to your phone. Select your speed sensor, you should be able to enter your wheel circumference from there. Hope that solves your problem.


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## skhan007 (May 18, 2012)

OK, here's the reply from the kind folks at Wahoo:

_"The Wahoo Fitness app is pulling the data from your sensors, where as the file we send to Strava is the raw GPS file because they do not accept speed sensors. The trees are causing the GPS signal to be very weak and this is the reason for the discrepancy."_

In short, when I'm riding on the multi-use trail (lots of tree coverage), this nonsense happens where I get short changed on my total miles and average speed. When on the wide open and dangerous roads, this doesn't happen; the feeds from my Wahoo screen match what is uploaded to Strava.


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## CrankyMinion (May 26, 2014)

I don't know about trees affecting signal, I thought phones use cellphone signal to locate itself. I guess it's possible. Does the route plot look funny to you? You can do a ride in an area with good signal and see what happens.


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## LVbob (Mar 24, 2014)

skhan007 said:


> OK, here's the reply from the kind folks at Wahoo:
> 
> _"The Wahoo Fitness app is pulling the data from your sensors, where as the file we send to Strava is the raw GPS file because they do not accept speed sensors. The trees are causing the GPS signal to be very weak and this is the reason for the discrepancy."_
> 
> In short, when I'm riding on the multi-use trail (lots of tree coverage), this nonsense happens where I get short changed on my total miles and average speed. When on the wide open and dangerous roads, this doesn't happen; the feeds from my Wahoo screen match what is uploaded to Strava.


The tree coverage can be a problem for GPS. 

My distance data in the app I use and the distance on Strava always match but average miles per hour is always a bit lower on Strava. I need to do a rollout on my tire to make sure the tire circumference is set properly in the app.


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## duriel (Oct 10, 2013)

That is why I use a GPS speedometer.... don't need no stinking wheel circumference!


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## Camilo (Jun 23, 2007)

dmarsey1 said:


> Rode with a friend today, I with a Garmin 500 he with strava on the iPhone. His showed the same exact distance but showed 300' more of climbing. Going to go with the Garmin as being more accurate.


I always go with whichever device gives me the fastest average, the longest distance or the most climbing. Accuracy be damned, I want the big numbers!


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## LVbob (Mar 24, 2014)

Camilo said:


> I always go with whichever device gives me the fastest average, the longest distance or the most climbing. Accuracy be damned, I want the big numbers!


Do you mix and match?


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## Scottfe (11 mo ago)

skhan007 said:


> I've been noticing that when I do a ride, my Wahoo data looks to be quite accurate, but when I upload to Strava, it states that I've done a lot less miles and a lot lower pace. For example, I went out for a quick 26 miler on my local multi-use trail, starting a mile marker 20 and turning around and returning at mile marker 33.
> 
> After uploading the Wahoo data to Strava, the Strava data short changed me 5 miles and 2 MPH on my average speed. Does this happen with you guys? Is this something I email Strava about?


I’ve been struggling with this as well. So for comparison I ran a little test. I tracked my ride with my Wahoo Element Bolt, on Strava (using both my Apple Watch and iPhone), and two friends used their Garmin units.
After a 25km fatbike ride the two Garmin units recorded 25.2km, the phone and watch were at 23.2 and 23.5km, and my Wahoo was at 22.6km!
I run just the Wahoo head unit with no sensors.
I have been seeing the same results for more than a year with others who run Garmin.
I tend to be a bit faster than the others slowing or stopping occasionally for them to catch up, is it possible auto pause is causing this issue, not turning back on fast enough? I’m almost ready to switch back to Garmin! I could hear my unit sound when pausing and seems to take a fair amount of time to restart…based on the sound.


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