Speed reading


Why does Zwift say I am going 2MPH wen my Garmin says 15MPH? It is hardly accurate. Speed Sensor has a brand new battery. Website doesn’t give very thorough user info in general.

(Paul Allen) #2

Were you going up a hill in Zwift?


Yes. Who goes 2MPH up a hill? What is the ZWIFT program basing that data on? Should I be in a super hard gear then to match ZWIFT speed to Garmin Speed? I was in a medium gear but not so hard I could barely turn a pedal which is what 2MPH would indicate.

(Paul Allen) #4

I am guessing you were going up the steep hill on Richmond. If you are just using a Speed and Cadence sensor then I don’t really see an issue, it looks like Zwift was calculating it pretty good. Just because your Garmin is saying your rear wheel is spinning at 15mph does not mean you will be going 15mph up a hill in Zwift. 

(Paul Allen) #5

Check this site out for more info: http://www.titaniumgeek.com/cycling/zwift-user-manual-unofficial-running-updates/#zPower



So even if you pedal faster it doesn’t matter?

(Paul Allen) #7

If your rear wheel spins faster you will speed up in Zwift. Your cadence + plus your gear = wheel speed/watts and thus you will go faster in Zwift. Zwift is calculating your watts based on your wheel speed and your weight to make an educated guess on how fast you are going in the game. I hope that makes sense. This is just a guess that you are using a dumb trainer and just a speed and cadence sensor.


Correct. It’s all dumb:)

thanks for your help!