Originally Posted by
spelger
i think we can all agree that neither would be correct.
^This.
Both are "guestimates" rather than based on actual power data. With your setup, Zwift is basing it's power reading on the speed of your rear wheel (and some calculations it knows about trainer power curves). It can be anywhere from pretty close to a fair way off. It can also vary depending on tyre pressure, roller tightness, trainer age and wear, etc. It's a means t oget you riding on Zwift, but it's not real power data.
Strava bases it's power estimates on, ummm, I'm actually not sure. They can also be anywhere from close enough to wildly out. I find uphill segments are actually the closest as I guess it takes out the effect tof wind, drafting, traffic, etc.
But at the end of the day, if you want real power data, but a real powermeter.
Oh and as for your average speed in Zwift, their algorithm is very optimistic. It gives you a very good CdA, plus there's no stopping at lights, slowing for corners, etc.
