Aligning Power on different bikes

[spangelsaregreat]

Hi,

I have two bikes I use on the road. Both are set up on PowerPod in separate profiles with different speed sensors. Both profiles were set up on the same day last year using the same bit of road to do the best accuracy calibration.

In the last few weeks I have been alternating between the two on a regular basis and I have noticed that for similar rides I get different average power values. I did notice this last year but didn't look into it any further.

Now I do appreciate that average power will differ from ride to ride depending on routes, wind, effort etc. However, it is noticeable that one bike is recording average power that is about 30 to 40 watts higher than the other bike.

An example I did two threshold rides (riding as hard as I could for about an hour) as follows:-

Ride 1 training bike Profile 1 - average power 206w NP 236w
Ride 2 road bike Profile 2 - average power 244w NP 266w

I notice similar differences on other types of rides, Tempo, Endurance ride etc again about a 30 to 40 watt difference.

So is there anything I can tweak in one profile to bring them more into line? For example could I raise or lower the CRR value on one profile to increase or reduce its average power?

Regards

[mir]

Is the physical(your) settings identical for the two profiles, weight, hand positioning etc.?
Is the physical(bike) settings idenfical, eg positioning of PP, weight, wheel size etc?

[Velocomp]

Hi,

I have two bikes I use on the road. Both are set up on PowerPod in separate profiles with different speed sensors. Both profiles were set up on the same day last year using the same bit of road to do the best accuracy calibration.

In the last few weeks I have been alternating between the two on a regular basis and I have noticed that for similar rides I get different average power values. I did notice this last year but didn't look into it any further.

Now I do appreciate that average power will differ from ride to ride depending on routes, wind, effort etc. However, it is noticeable that one bike is recording average power that is about 30 to 40 watts higher than the other bike.

An example I did two threshold rides (riding as hard as I could for about an hour) as follows:-

Ride 1 training bike Profile 1 - average power 206w NP 236w
Ride 2 road bike Profile 2 - average power 244w NP 266w

I notice similar differences on other types of rides, Tempo, Endurance ride etc again about a 30 to 40 watt difference.

So is there anything I can tweak in one profile to bring them more into line? For example could I raise or lower the CRR value on one profile to increase or reduce its average power?

Regards

Please post ride files from each bike.

[spangelsaregreat]

Hi John,

Ride files attached.

The 4/4/20 ride is my training bike.

The 11/4/20 ride is my road bike.

Regards

[spangelsaregreat]

Hi John

Have you had a chance to look at the two rides?

Regards

[Velocomp]

Hi John

Have you had a chance to look at the two rides?

Regards

OOPS...this one dropped through the cracks

You've got large winds on both ride files. It's difficult to tell if the calibrations are correct. I do see that stronger headwinds on your 4/11 ride. They seem suspiciously high. High wind would cause high watts.

Try to find a calmer day for some rides, and post those ride files.

[spangelsaregreat]

John

I am pretty sure from checks you did last year my training bike is calibrated fine. I have only done commutes on it in the last week so all ride are in one direction. I have done a ride with lighter winds on my road bike which I have posted below also, which is the one I suspect is reading slightly high watts.

The 25/4/20 ride is my road bike. Wind was 3mph from the NNW.

Regards

[spangelsaregreat]

John

Did you get a chance to review this ride (a lot less windy). As I said before, I think this bike profile may be over reading watts by about 20 to 30 watts.

Regards

[Velocomp]

This profile looks to be perfectly calibrated.'

I took two sections of your ride, one on a hill, one on the flats, and compared PP data to aero coach. Hills and flats checks the calibration of the accelerometer and wind sensor respectively.

http://www.aerocoach.com.au/power-from-speed/

Your device is working very well.

[spangelsaregreat]

John

Thanks for checking, must be the "good bike" effect making me try harder.

Regards