Differences between how Strava and Ride with GPS calculate metrics

From reading this website, I learned that Ride with GPS is a local company. Maybe because they are a local company, their selection of routes to choose from is great. So, I started using Ride with GPS to plan and record my rides. I export (auto-sync) to Strava for a lot of its social features; it keeps me in touch with friends in distant places who are also cyclists.

But Ride with GPS and Strava calculate their metrics differently. Below is an example. Beginning in Hillsdale, I rode an out-and-back along Multnomah Blvd. west and then the Fanno Creek Trail. Ride with GPS says the route climbed 1006ft of elevation. Strava says 769ft. There are other minor differences, like in Avg Moving Speed, but the difference in elevation is more significant. Anyone know how they reach different calculations? Or are these data points not comparing the same thing? Now, I’m wondering which one is right.


Speaking to a possibility with no idea if it’s accurate in this particular scenario or not: were there any bridges or overpasses involved? I’ve noted that bike tracking programs will show that I went downhill and then uphill going over the Broadway Bridge (instead of climbing first and then descending) because they’re reading the topography elevation and not the bridge’s elevation. Some apps that can pull as much data a possible from your smartphone will rely on the electronic barometer readings (if so equipped) to get their elevation data. I believe Strava is one of them.

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https://ridewithgps.com/help/grade-and-elevation

https://ridewithgps.com/help/replace-elevation

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You two are on the right track. I posed the question to Ride with GPS and had a great exchange with Dylan on their staff. Shout out to Ride with GPS for some awesome customer service!

I learned there are two things going on here. The first is that RwGPS uses the barometric altimeter in my iPhone to calculate elevation gain/loss, and when there is a significant weather front coming in, the barometer can be thrown off. Dylan tracked that down by focusing on two moments in my ride, when I crossed Hwy 217 at the the SW Denney Rd overpass. Presumably, the altitude should have been the same, but the return ride was 15 ft higher. He supposes that the difference is a product of the barometric pressure dropping during my ride, because of a low pressure system coming in (the same one that is now dumping all this rain on us). On days when the atmospheric pressure drops dramatically, there can be an “inflation” in elevation changes.

Second, the difference between RwGPS and Strava has to do with the “smoothing” that each platform’s algorithm performs. Strava is more aggressive about this. RwGPS pings the altitude more often, so in general it should be more accurate, but on this day’s ride, the change in atmospheric pressure showed that I climbed more than I probably did.

Fascinating what all these magic internet devices in our pockets and on our handlebars are doing.

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Elevation is all over the place… depending on apps and devices. I ride with a group often. Even when we are all together, we will get different climbing totals… sometimes varying by hundreds of feet over a 30-40 mile ride.
And ‘smoothing’ by app software also plays a major role in all the metrics. I started tracking with MapMyRide years ago, then added Strava because that’s what most friends use. MapMyRide consistently logs 10-15% more climbing and 5-7% LESS mileage. I don’t know which is more accurate on climbing, but Strava is definitely more accurate with mileage.
I have bike computers with wheel sensors on three different bikes… they all closely agree (and also match the mileage markers on the Springwater, etc.). Strava comes within 1% of the wheel sensors (low by .3 on a 30 mile ride), but MapMyRide is always much lower: 1.5 miles off after 30 miles.
I have submitted numerous reports to MapMyRide, but they wrongly insist they are more accurate.

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