Adjusting Parameters - Check Calibration

[lorduintah]

John -

Isaac identifies 6 parameters that are used to establish the power during a ride.

Of the six, two are held and the remaining 4 are adjusted when checking the calibration. The variables held constant are selectable using the advanced options. When installed, Isaac has these set in a default configuration.

Which brings me to the questions about what variable are best to be held at the initial settings and why those?

Can you change the ones that are held constant and retry the check calibration - on the fly? So that one could see the impact on calibration by a variety of variable combinations? I think I have tried this without success, but I may not have been implementing this correctly.

Finally, what issues might lead to negative friction estimates (admittedly an unrealistic parameter.)

Thanks,

Tom

[Velocomp]

Ahh...you are poking deep into the innards of our system

The 6 variables go all the way back to our original iBike product from 2005. I don't want to describe too explicitly how the variables relate; suffice it to say that there are two variables (CdA and Crr) that can be user-adjusted after the completion of a calibration ride. Wind Scaling and riding tilt are determined during the cal ride.

In general, leave WSF and riding tilt unchanged. Click on the radio buttons next to WS and RT if you want to adjust CdA or Crr.

If your unit is rotated on your bike after the cal ride, reported friction can become negative. This obviously is not correct; what is happening is that internal recalibration has compensated for the rotated unit, sometimes resulting in a negative friction. The best way to fix this problem is with a new cal ride.

[lorduintah]

Thanks -

Yes I have seen the relationship between parameters - while I have figured out the relationship, getting to the parameter value that result form checking or generating a set of calibration parameters I will not dive into - and I have had negative friction after running Cal Check occasionally - but I also have a mount that does not rotate to cause this - the Up Front mount has been tightened to the 5nM requirement for my carbon bar - I could practically stand on it and it would not rotate. The PP is also tightened and does not rotate at all - and I do not remove the PP from the bike for any reason, so the tilt that exists is a constant. relatively speaking.

BUT, that said, I now have a Specialized Roubaix S-WORKS with the Future Shock Fork. I have seen some calibration issues and reproducibility if I have this feature enabled. Locking the extra motion out and the calibration is very reproducible.

Tom