profile numbers - appropriate ranges?

[berveling]

I would be grateful for comments with respect to the profile numbers. I suspect I don't need to know what they all mean, but I understand it is important to have them correct. But I wouldn't know if they are.
Is it possible to have an appropriate range for the various figures?
For example, for my road bike, the last 2 profiles provide respectively the following numbers (with the first numbers belonging from the current profile, and the 2nd ones from the previous one): aero: 0.281/0.271; fric 6.890/6.165; CdA 0.329/0.330; crr 0.0055/0.0055. Do these sound right?
The numbers for the last 2 profiles for my TT bike are similar, except for a 31% change in fric (is that important??):
aero: 0.206/0.214; fric 9.067/6.890; CdA 0.227/0.212; crr 0.0055/0.0055.
With the TT bike, after I did the new cal ride and coast downs and got the new profile with the larger fric, the iBike suggested that I was pumping out about 60% of expected power, whereas my legs loudly told me otherwise. Maybe just coincidence?

[racerfern]

The numbers in and of themselves seem to be in line with normal numbers. However to know for sure, we also need to know your windscaling number and your total weight for each profile.

As far as the TT bike, the wind scaling number may be the culprit. Post up some more data if you could.

[berveling]

Thanks for your interim reply
I've aded the wind scaling numbers to thte figures, so that all the figures are as follows:
For my road bike: aero: 0.281/0.271; fric 6.890/6.165; CdA 0.329/0.330; crr 0.0055/0.0055, wind scaling 0.854 / 0.820
For the TT aero: 0.206/0.214; fric 9.067/6.890; CdA 0.227/0.212; crr 0.0055/0.0055; wind scaling 0.906 / 1.010
The total weight has been consistent at 163lb in all cases.

[coachboyd]

If the friction is vastly different, that could be because the tilt was slightly off on the calibration ride and the riding tilt is more than reported.

Looking over your numbers, you are getting very consistent numbers between your two profiles, and the values fall right in the ranges I would expect to see. I would be VERY confident in your profile for both bikes and would go out and enjoy your riding!

[lorduintah]

One of the usual suspects involving tilt is the sturdiness of your clamping. If the iBike can move, the tilt will change. Movement typically will take place when you are pressing the red button - does not matter which part of it. So IF you check your tilt calibration (180 degree check to get +/- the same absolute tilt) in the same location and it varies often (you find you have to re-calibrate a lot), the clamp may be loose - this can be somewhat subtle. Another symptom of this can be while running coast downs - you get a lot of bad CDs. This also can be due to movement in the iBike mount.

I would expect each bike to have different parameters and wind scaling, too. This is due to a plethora of factors too long to list.

Tom

[berveling]

Dear Tom and Boyd

Thank you for your confirmation that all seems pretty good with my calibrations. I will double check the sturdiness of the mount on the TT bike. To overcome the current discrepancy between its 2 fric results, i"ll do a further Cal ride and hope that its fric result is close to one of the previous calibration rides. Then i can assume that the other was an abberation. If it's in the middle, then I will have a compromise number!

[Gadget]

Would you mind commenting on my road bike profile?

Aero: 0.206; Fric 6.211; Wind Scaling 0.967; CdA 0.213; Crr 0.0042; Riding Tilt -0.3%; Weight 195 (170+25); Wheel Circ 2102; Height 70in

[coachboyd]

hmm, your cda looks a little low to me.
Can you send me a solo ride file to boyd (at) totalcyclist dot com

also in your documents->iBike rides->calibration rides you will see an ibcd4m file from when you did your coastdowns and cal ride. If you can send that to me then I can get you all set.