Can't calibrate ride?

[ScottChapman]

So, I did a successful calibration ride, however when I try to load it into the software, I select the portion of the ride that was out and back, but the calculate button on step 4 of the dialog is always grayed out.

Any ideas?

[Velocomp]

Please post the ibcd4m file.

[ScottChapman]

Perhaps because I had set the data sampling rate to 5 seconds last week?

[Velocomp]

All is well. What is going on is a quirk in the iBike software that we will fix on a future revision.

You used Fast Start (a very good idea) then did the cal ride. The iBike automatically calibrates itself and you're done.

If you choose to download the Cal Ride, the window is grayed out because no coast downs were done. Coast Downs weren't needed because you used Fast Start. In fact, the software simply recalculates the same numbers that were determined in the firmware.

So, everything is in order. Once we fix this iBike software bug this won't create the questions it can cause right now.

[ScottChapman]

Cool, so the iBike already has the new profile loaded? My power numbers looked better than before, so I wanted to apply them to some recent rides...

And thanks John.

[Velocomp]

To apply your profile to your older rides do the following:

1) Load a ride file that has your newer profile.

2) Go to Profiles/Edit Profiles.

3) Click the Extract from Ride File button. Your new profile is extracted. Give your new profile a unique name then click Accept

4) Open one of your older ride files.

5) Go to Tools/Switch Profile after the Ride

6) Select your new profile, then click Accept.

7) Your old ride files will have the new profile applied.

[ScottChapman]

Do the numbers in the profile look good to you?

And is it worth re-doing the cal ride using a 1sec sampling rate and doing some coast downs?

[Velocomp]

Your Cal Ride numbers look fine. There is no need to do a "1 sec" cal ride. The Record rate is only the rate at which the iBike records data to the external ride file. The internal calculations are always done at a high data rate.

Coast downs really are not needed unless you are trying to compare your absolute watts to Mark Cavendish's. And if you are doing this comparison, please tell us your jersey number so we can be looking for you on TV...

[ScottChapman]

the iBike was calculating around 20% lower power than my DFPM on my recent ride.

[Velocomp]

Please post both ride files

[ScottChapman]

Here is from the ride today.

[Velocomp]

It appears you did a solo ride for the first 30 miles, then a group ride afterwards.

Assuming this is correct, and that you did a Cal Wind prior to starting your ride, then you show a slight negative wind for the first 30 miles.

As a guess, I assumed that you had zero net wind for the first 30 miles. I adjusted your wind scaling factor (upwards) to 4.16 so that your ride file showed zero net wind.

Once I did this your watts matched almost exactly, both for the first part of the ride and for the ride overall.

The modified profile is attached. Load it into your iAero and see if you get better agreement.

[ScottChapman]

The entire ride was a group ride. I did get a good wind calibration to start, and then re-did it around mile 30 when we stopped.
When I apply this profile to the ride (after the ride) it looks like it is showing 10% lower power instead of 20% lower (by my eyeball calculation). Certainly better, but not great.

[ScottChapman]

Any chance of getting it tweaked to be closer??

Also, I have another bike I would like to use. I am trying to get it to be as similar in terms of weight, fit and position on the bike as the one I am using now. What are my options since I can't seem to get a reliable calibration?

[Morocco Mole]

Scott

In my experience, a group ride is not a great choice to use for tweaking profiles to match your DFPM. I usually use a couple of solo rides, possibly a flat TT type ride, maybe a couple of 2 x 20's , and then a 10 minute hill climb. In this way you can play with CRR and CDA and see the results under different ride conditions. eg I might look at my flat TT portion of the ride and see if the iBike is over or under reporting power, at these higher speeds it is normally CDA that tends to be the contributing factor so I will tweak that up or down. I would then check the Hill Climb portion as the CRR has more of an impact so I might tweak that value. You will need to go back and forth tweaking both values, with the aim to get the power matching your DFPM under both conditions which normally indicates you have both CDA and CRR pretty close to correct. If temperature is varying I would do a wind cal before each critical part of your ride.

Regards
Jim