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Calibration Proceedure question

Posted: Sat Nov 15, 2008 1:26 pm
by cjonbike
Got a question on getting my profile on my new iBike.

I do a tilt Cal and wind offset (while off the bike).
I then do a bunch of coast downs (while on the bike which inherently changes the tilt).
I then do a 2 mile out and 2 mile back, which calculates the riding tilt and wind offset and such. This is after the coast downs

When you do the coast downs how can it correctly calculate it's magic when the tilt has to be off because it does not know the riding tilt at the time? It has to some calculating then or it would not come up with BAD CALC.

I know I am missing something just not sure what :?

Thank you for any enlightenment

Chris

Re: Calibration Proceedure question

Posted: Sat Nov 15, 2008 1:51 pm
by Velocomp
If you are getting a "bad cal" message at the end of your calibration ride then either your tilt calibration was incorrect prior to starting your cal ride or wind offset was wrong. Check your tilt calibration and wind offset prior to doing the cal ride.

Re: Calibration Proceedure question

Posted: Sat Nov 15, 2008 2:48 pm
by cjonbike
Cool will be more careful on the cals.

Guess my main question lies in when does the all the values for the profile get figured, like cda, crr, friction, is that in the processing in iBike 3?

And you get a good Tilt cal, then when you sit on the bike the ibike will tilt a hair forward or back, if it didn't you would not need a riding tilt, so when you are coasting down if the iBike is tilted a little more up because it is tilted and not because the slope is going up, wouldn't the friction be off? or tilted down.....

Is this all figured after the fact when you down load the profiles on the computer as then you have the riding tilt?

I do Thank you for your help and patience. This is one great product, I know it works, just curious on some of the details.

Chris

Re: Calibration Proceedure question

Posted: Sat Nov 15, 2008 3:47 pm
by travispape
cjonbike wrote:Guess my main question lies in when does the all the values for the profile get figured, like cda, crr, friction, is that in the processing in iBike 3?
Good question. For GenIII the calculations for a profile can happen in the following ways:

GenIII:

On the road, in the unit:
1> 1 coast-down only
2> 1 coast-down with calibration ride
3> Estimated CdA (and entered Crr) only
4> Estimated CdA (and entered Crr) with calibration ride

In iBike3:
1> multiple coast-downs <---<<< Strongly recommend #2 instead
2> multiple coast-downs with calibration ride <---<<< best choice if you don't have a DFPM
3> calibration with DFPM (either ANT+Sport or sycrhronized later) <---<<< best choice if you have a DFPM

You will get the best results processing the cal data in Bike3; however, it is fine to do a quick profile on the road and ride with it until you have a chance to process them at your computer. For a quick profile on a windy day, choose option 4. The unit does not process multiple coastdowns--it only uses the most recent one. If the wind is perfectly calm, option 2 might give a better result than option 4.
cjonbike wrote:And you get a good Tilt cal, then when you sit on the bike the ibike will tilt a hair forward or back, if it didn't you would not need a riding tilt, so when you are coasting down if the iBike is tilted a little more up because it is tilted and not because the slope is going up, wouldn't the friction be off? or tilted down.....
Yes, and that is ok. For every option, the riding_tilt phenomenon is handled automatically--you don't need to worry about it. It is best to do your tilt_cal off the bike. In the past, some people liked to do their tilt cal while sitting on the bike in order to see more accurate slope information while on the road (ever since the beginning of iBike2, the slope information viewed on the computer has been accurate). With GenIII, there is no reason to do this. Even if you do your tilt cal off the bike, the slope you see when riding will be accurate.

Take home point: do your tilt cal off the bike as you have been.
cjonbike wrote:Is this all figured after the fact when you down load the profiles on the computer as then you have the riding tilt?
Both--see above.

Good questions--hope you enjoy the unit.

Re: Calibration Proceedure question

Posted: Sat Nov 15, 2008 3:55 pm
by cjonbike
Thank you both so very much, y'all are the best

Chris