Re-calibration Necessary?

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wjwlitespeed
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Joined: Mon Apr 15, 2013 7:52 am

Re-calibration Necessary?

Post by wjwlitespeed »

Is there any reason to do another calibration for this season? My weight and bike setup are they same as last spring when I last did a calibration.
Does anything in the electronics drift over time that warrants a re-calibration from season to season?
Thanks
Velocomp
Velocomp CEO
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Joined: Fri Jan 11, 2008 8:43 am

Re: Re-calibration Necessary?

Post by Velocomp »

No need to recalibrate.
John Hamann
thooey
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Joined: Wed Mar 11, 2015 9:00 pm

Re: Re-calibration Necessary?

Post by thooey »

As I lose my winter weight (optimistic) and also ride more in shorts and short sleeves, should I also re-calibrate or just adjust my rider weight? My calibration ride was done with vest, arm and leg warmers and if I drop 4-5 lbs from that point is that enough of a change to re-calibrate? Thanks.
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Russ
Posts: 370
Joined: Sun Feb 10, 2008 4:08 pm

Re: Re-calibration Necessary?

Post by Russ »

Hi Thooey,

I will take a crack at your concern.

The calibration ride sets two things, the tilt offset with you on the bike in your normal position and the air pressure sensor offset for it's position in the airstream around you and the bike. The airstream position affects the pressure that the iBike senses because of airflow dynamics - think higher pressure areas of compressed air flow over the surfaces.

The weight you change will only marginally change the tilt normally, probably not even measurable besides the iBike now corrects that on the fly and saves it new correction at the end of a ride with the reset.

The aero dynamic drag change for your clothing makes a slight difference and can be set with coast downs, which are where this is teased out of the data along with rolling resistance. Velocomp has gone to some lengths to make the need for coast downs unnecessary. I find the biggest difference clothing makes is if I wear a baggy windbreaker and especially if it is not totally zipped up. So if you used the estimation process, you could take a look at that and tweek the cda value a bit in your profile or do new coast downs.

Just a few thoughts on the matter,
Hope this helps.
Russ
thooey
Posts: 37
Joined: Wed Mar 11, 2015 9:00 pm

Re: Re-calibration Necessary?

Post by thooey »

Russ, thank you, that helps explain it for me.
stefun
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Joined: Thu Jun 27, 2013 11:37 am

Re: Re-calibration Necessary?

Post by stefun »

Hello,
I have another question about re-calibration:
Two weeks ago, I raise my handlebar 2 cm higher.
Since this change, it seems that ibike give numbers higher than previously, on the same circuit and the same wind conditions.
For example, the power output was 194 watts (vs 199 against a DFPM) before the change, and now Ibike output is 227 watts (no DFPM numbers). Heart Rate data were comparable and speed too.
Do you think I need to Re-calibrate the newton with this new position of the handlebar?
Thank you.
Velocomp
Velocomp CEO
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Joined: Fri Jan 11, 2008 8:43 am

Re: Re-calibration Necessary?

Post by Velocomp »

Whenever you move your Newton in a way that changes either its angle on the bike, or its position in the wind, it will require recalibration.
John Hamann
stefun
Posts: 19
Joined: Thu Jun 27, 2013 11:37 am

Re: Re-calibration Necessary?

Post by stefun »

Many Thanks for your quick reply
JulianBoulter
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Joined: Wed Jan 22, 2014 5:38 pm

Re: Re-calibration Necessary?

Post by JulianBoulter »

Velocomp wrote:Whenever you move your Newton in a way that changes either its angle on the bike, or its position in the wind, it will require recalibration.
Just to check, I have a RWS mounted (with which I performed the calibration ride a couple of years ago) which I now want to remove. Am I right in saying I dont need to perform the calibration again if I now remove just the RWS but keep everything else just the same?

Thanks
Velocomp
Velocomp CEO
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Joined: Fri Jan 11, 2008 8:43 am

Re: Re-calibration Necessary?

Post by Velocomp »

Removing the RWS is the same as changing the position of the Newton in the wind, so you should do a new calibration ride.
John Hamann
JulianBoulter
Posts: 62
Joined: Wed Jan 22, 2014 5:38 pm

Re: Re-calibration Necessary?

Post by JulianBoulter »

Velocomp wrote:Removing the RWS is the same as changing the position of the Newton in the wind, so you should do a new calibration ride.
OK Will do, thanks John
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