Should I get the same power readings with trainerroad as a bike computer? The reason I ask is that it doesn’t require the crank length. Or is this updated with the Vector updater app so it pulls this information?
Trust the Vector if you have the torque readings correct. Trainerroad isn’t accurate at all.
I’m using trainer road with the vectors. I’m not using virtual power. I was just wondering if trainer road power numbers from Vector would match bike computer?
What is accurate? What company is the most accurate? What proof do they have to back it up? I want consistent.
Yes, you should get the same values. The Vector Updater app can be used to set the crank length in the firmware on the pedals.
The numbers we display and record come directly from the Vectors. The Vectors store the crank length so you should see the same power readings on TrainerRoad as you would on a Garmin Edge or other cycling computer. We don’t have a way to change the crank length or display it in TrainerRoad right now, though.
Correct me if I’m wrong, but isn’t the computation of power done on the Vector unit itself (as opposed to whatever head unit it’s transmitting to)? I.e. the Vector is not transmitting “X Torque, Y Cadence” to the computer to infer Power, but it’s actually transmitting “X Watts” to the computer…so it should be impossible for TrainerRoad and the Head Unit to have different values?
Only thing I could think of would be update rate between software, but even then, I believe ANT+ is a constant 1" refresh rate?
Correct me if I’m wrong, but isn’t the computation of power done on the Vector unit itself (as opposed to whatever head unit it’s transmitting to)? I.e. the Vector is not transmitting “X Torque, Y Cadence” to the computer to infer Power, but it’s actually transmitting “X Watts” to the computer…so it should be impossible for TrainerRoad and the Head Unit to have different values?
Only thing I could think of would be update rate between software, but even then, I believe ANT+ is a constant 1" refresh rate?
Trainer road, Edge 800, and 910xt all give me different wattages with my vectors. Not enough for me to care though.
Correct me if I’m wrong, but isn’t the computation of power done on the Vector unit itself (as opposed to whatever head unit it’s transmitting to)? I.e. the Vector is not transmitting “X Torque, Y Cadence” to the computer to infer Power, but it’s actually transmitting “X Watts” to the computer…so it should be impossible for TrainerRoad and the Head Unit to have different values?
Only thing I could think of would be update rate between software, but even then, I believe ANT+ is a constant 1" refresh rate?
Trainer road, Edge 800, and 910xt all give me different wattages with my vectors. Not enough for me to care though.
Check power smoothing. If you have different smoothing values in each head unit you’re going to get different numbers. That’s where I would look first. Try turning smoothing off on each unit and see if they match.
TR will display power updates a little more quickly than the 800 and the 910xt. That’s because your computer has a faster CPU in it compared to cycling head units and watches. The overall difference is like 1/4 to 1/2 second though.
Thanks for the reply. My crank length is 177.5. So the vector pedals think they are 172.5mm right now. How much difference in power should I expect? Is this linear relationship?
I’m not sure what the difference would be.
Did you check the power smoothing on your displays? Even if the crank length was off it should be off for all of the head units…at least I think so :).