Wahoo vs Strava
 

I’ve noticed there is usually a slight discrepancy between the two at the conclusion of my rides. I have a favorite hill I enjoy flying down and today Wahoo said I hit 43.2 while Strava said 44.9.
Is one more accurate than the other?

As Mark Twain said about watches, “A man with one watch knows what time it is; a man with two is never sure.”

Personally, I believe a cheap speedometer first, followed by the (processed data) GPS, with post-processed GPS data a distant third. Of course Strava gave you a mile and a half per hour better answer, so which do you want to believe?

+100

Wahoo? The device itself or some site of theirs you load your ride to?

Different places might derive the numbers differently. If you tell me you hit 44.9 mph, I'm not going to care if it was only 43.2 mph. All I'm going to do is think that you went downhill fast.

It was my ELEMNT that recorded the 43.2, the connected Strava gave the higher number after processing the data from the Wahoo device.

If you are certain that your Wahoo is giving you the correct total distance for all your rides, then I'd probably go with the Wahoo if you have to feel honest when you get to telling tales of the great ride with your bud's. You aren't a fisherman are you? At least not a fisherman that tells tales. <grin>

Remember that your log file doesn't contain every moment of your ride. At best it might have 1 second intervals. But even 1 second recording is missing over 58 feet of your actual path at 40 mph. So differences from what the Device that is getting multiple data points to read in that one second of time to Strava and others that are limited to data sets further apart can be different. And if one or several of the plots in the log file was suffering accuracy problems due to satellite reception issue of any sort, then that might play a role in the difference too.

I'd tend to trust the device that was actually there rather than the software that calculated speed based on GPS positioning estimated elevation (to account for distance changes that don't happen in (X,Y) space that the GPS won't pick up). On the other hand, unless you have a connected, calibrated, wheelspeed sensor, all your Elemnt is doing is tracking GPS changes and applying them to estimated elevation as well. Just a different algorithm and different estimates.

being honest; if you can find a radar service car (traffic enforcement) , ask them to beam you as you're recording on your device(s). it would be about as legally accurate as you might get for cheap. Mine was verified by the LEO. Bicycle mounted computer was a tad more accurate than the phone app.

Segal’s Law. https://en.wikipedia.org/wiki/Segal's_law

Related to the subject matter, I noticed my new Garmin 1040 is reporting higher top speeds than my previous 530. The new 1040 model is supposed to be more accurate since it uses multi-band gps.

You didn't mention how your speed is measured. Speed sensor or GPS. GPS is not as good for instantaneous speed calculations. There's the potential for all sorts of unknown processing. Obviously if Strava is getting the data from the Wahoo, and they were both simply looking at the single highest value of speed, they should both report the same value. But it's possible that one or both are doing some processing of the data. More than likely some form of data smoothing (filtering) and they just do it differently.

Maybe the Wahoo is computing the highest N second average speed while Strava is reporting the single highest speed value. Both can be correct, it's just a matter of the definition of what max speed is for their respective methods of calculation.

If having the most accurate speed values are important to you, then get a speed sensor if you don't have one. My Garmin 530 can auto calibrate this using GPS data. I'm sure many other bike computers do was well. GPS is great over longer distances, so this calibration can work well. But the speed sensor will be much better than GPS for things like peak instantaneous speed.

Good thread.