How is elevation gained determined on a ride?

Y’know the old phrase “a man with 2 watches will never know what time it is”? I’m starting to feel that way about trying to know how many feet I’ve climbed on a ride. I just did a gravel grinder called the Natchaug epic yesterday (for anyone who wants to travel to Thompson, ct. it was fun, try it next year)and I’m finding a discrepancy in the elevation gain, both pre and post ride. The original ridewithgps link they sent out says 3625 feet gained and my wahoo elemnt app says 5688 ft. Afterwards my wahoo file says I climbed 2779 and ridewithgps says I climbed 3014. On strava other folk I did the ride with got a range of numbers such as 3366, 4172, 2920, 2848, and 4135. Now we all did the same course, the maps are all the same and yet we all climbed different amounts. How is this so? Does anyone have any insight as to why different apps, devices or services yield such drastically different amounts for elevation gained?

It’s complex.

Drove me crazy after buying my first bike computer. GPS accuracy isn’t good for elevation. Better bike computers use barometric altimeters, along with some data processing to estimate elevation. Like I said, it’s complex.

I guess the question at this point is which is the most trustworthy source? Is it the pre-ride ridewithgps or whatever plotting website, the post ride website data, or the bike computer’s onboard altimeter?

Wow, I’ve always taken Strava vertical gain numbers with a grain of salt, but I don’t think I ever would have guessed it was that far off, or inconsistent.

ridewithgps routes typically overestimate elevation gain by 10-25%.

GPS only elevation will also tend to overestimate. As mentioned above, computers with barometric altimeters will produce better results, but they can be subject to changing weather conditions over the course of a ride.

There does seem to be a cluster of results around 2900 - I’d go with that.

No, but it’s even worse than you imagine :slight_smile:

If I record a session in the PowerTap app, that sync the same data to Strava, which then syncs the same data to TrainerRoad…I get three different sets of data displayed in each app! :laughing:

Kudos for the man with two watches phrase, I haven’t heard that in decades, but it is so relevant to measuring training.