At the end of my second last ride (last 5 mins) I suddenly had slope values of up to 40% - hmm ok I thought of it as a temporary artifact. But today I had another ride and during the first 10 mins I had a slope +-30% but then the system settles (aka works as expected) for an hour when the problem reappears again and again. Any one any clue?
Ralph
NB I have added the file for today.
Random(?) slope issue
Random(?) slope issue
- Attachments
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- iBike_05_07_2015_0844_74_km.ibr
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Re: Random(?) slope issue
The ride file you attached shows the slope problem at the beginning of your ride. It does not show any slope problems later in your ride.
After 8 minutes of riding the slope calibration automatically corrects things, as it was designed to do.
Problems with wrong slope for the first few minutes of rides can be caused by one of two things:
1) your mount is not solidly fastened, and can rotate
2) Your Newton is turned on and your bike wheels are spinning even though you're not riding the bike. For example, this can happen if you put your bike in a bike stand for maintenance and spin the wheels, or if you change a flat tire during your ride, and spin the rear wheel.
When you finish each ride, make sure to turn your Newton off. This way, the Newton slope correction system won't get confused, even if your bike wheels spin.
After 8 minutes of riding the slope calibration automatically corrects things, as it was designed to do.
Problems with wrong slope for the first few minutes of rides can be caused by one of two things:
1) your mount is not solidly fastened, and can rotate
2) Your Newton is turned on and your bike wheels are spinning even though you're not riding the bike. For example, this can happen if you put your bike in a bike stand for maintenance and spin the wheels, or if you change a flat tire during your ride, and spin the rear wheel.
When you finish each ride, make sure to turn your Newton off. This way, the Newton slope correction system won't get confused, even if your bike wheels spin.
John Hamann
Re: Random(?) slope issue
Ahh ok good to know.
But actually:
1.) The mount is solidly fastened at the stem.
2.) To clarify IMHO the problem I see:
- the first 10 mins
- from 1:15 - 1:25 (Power=0W but at least two significant hills and biking near heart rate threshold, speed and cadence are ok)
- from 1:42 - 1:50 (Power=0W, slightly uphill but -6% in avg according to isaac and biking near heart rate threshold, speed and cadence are ok)
- from 2:14 - 2:18 (Power=0W, mostly flat but -7% in avg according to isaac and biking near heart rate threshold, speed and cadence are ok)
- from 2:22 - 2:27 (Power=0W, mostly flat but -6% in avg according to isaac and biking near heart rate threshold, speed and cadence are ok)
So for me it looks like the slope measure gets confused from time to time for a not obvious reason while biking. IMHO it randomly(?) measures a slope of << 0% and so 0W power output is calculated. So the question for me is what else can cause this.
Ralph
But actually:
1.) The mount is solidly fastened at the stem.
2.) To clarify IMHO the problem I see:
- the first 10 mins
- from 1:15 - 1:25 (Power=0W but at least two significant hills and biking near heart rate threshold, speed and cadence are ok)
- from 1:42 - 1:50 (Power=0W, slightly uphill but -6% in avg according to isaac and biking near heart rate threshold, speed and cadence are ok)
- from 2:14 - 2:18 (Power=0W, mostly flat but -7% in avg according to isaac and biking near heart rate threshold, speed and cadence are ok)
- from 2:22 - 2:27 (Power=0W, mostly flat but -6% in avg according to isaac and biking near heart rate threshold, speed and cadence are ok)
So for me it looks like the slope measure gets confused from time to time for a not obvious reason while biking. IMHO it randomly(?) measures a slope of << 0% and so 0W power output is calculated. So the question for me is what else can cause this.
Ralph
Re: Random(?) slope issue
If your tilt offset is incorrect, then the first 8 minutes of your ride will show wacky slope and watts. During this period the Newton is recalibrating itself.
The calibration gradually starts to correct itself at the 5 minute mark. It takes 2-3 minutes for the correct offset to take hold.
It's hard to know exactly why your offset was wrong at the beginning of your ride, but when it IS wrong, you simply have to wait a few minutes until your Newton recalibrates itself.
The calibration gradually starts to correct itself at the 5 minute mark. It takes 2-3 minutes for the correct offset to take hold.
It's hard to know exactly why your offset was wrong at the beginning of your ride, but when it IS wrong, you simply have to wait a few minutes until your Newton recalibrates itself.
John Hamann