wrong readings, no power displayed

[juancito27]

Hi,

Today after bunny hoping a hole, my Newton stop showing power. Also the speed displayed was a bit less than 50% of the actual one (distance as well); slope was displayed as about 40% more than the real one. Cadence and heart rate readings were fine.

I reset the trip, perfrom a scan and restarted the unit, and the result ws the same.

When I downloading the files on the computer, Isaac displayed a message that it founded a different wheel circunference (I enclose a screen capture) for each of the rides that I haven´t downloaded, even for the rides when the problem was not present.

At the end of the download Isaac displayed another message saying that many values were wrong. I nclose the screen capture as well.

Please let me know what to do to fix the problem.

Thanks

[Velocomp]

Please post your ride file

[juancito27]

Thanks for the reply.

Please pen the file. Also, the date and time of the ride was changed. I did it today in the middle of the day.

[Velocomp]

Your ride file is really messed up, sorry!

Please do the following:

1) Do a Hard Reset of your unit (press-hold center button for 10 seconds, until the screen goes blank, then release)

2) Connect your Newton to Isaac so that its date/time is reset

3) Do a short ride and post the ride file.

We will figure out what is going on.

[juancito27]

Thanks for the reply.

I just tried the hard reset and the screen never went blank, the closest was "data reset" after a lot of "8" passed moving very fast on the screen. I´ll do the ride and post it here.

[juancito27]

This is the file. It was basically the same route as yesterday. I think is still looking bad

[juancito27]

Here is a link of the same ride recorded with a Garmin Edge

https://connect.garmin.com/dashboard?cid=278374

[juancito27]

I just noticed that when I hold the Newton on my hand the reading of the slope changes rapidly and randomly -24, 32, 8, -33, etc

[Velocomp]

Somehow your profile became totally corrupted, causing all kinds of problems in your ride file.

Load the profile attached into your Newton (if you need help with this let us know), then try another short ride and post the result.

[juancito27]

Thank you for your reply, however, I was not able to send the profile you created to the device because it did not have my height, which is 182cm. I send screen captures showing this.

[Velocomp]

Your profile has become totally corrupted.

Connect your Newton to your computer, then use the command Device/Setup Newton...to create a new profile for your Newton. You'll need to do a Cal Ride.

Hopefully this will work.

[juancito27]

Hi there

I think the problems resulting from the bunny hop are history.

I was able to make the readings better using a profile from a past ride. This is the third ride I do with it and it looks like the files are the way they were before.
I´d like to ask you to please take a look of this file. To me there are inconsistencies and inaccuracy on some parts of the file.

Lap 1: the first part the device did not send the right information

Lap 2: It is just fine, as most of the time when I go uphill

Lap 3: From 6.3 to 8.2K no power displayed and I was pedaling, not braking as the color of the graph shows. From 8.9 to 9.7 I was not coasting, no power displayed when I think I was producing around 200w. This is a recurrent situation that I encounter every time I go on a hilly road or a flat one for that matter. There is no way to know how much power I´m producing and on a long ride in such terrain, and I cannot take advantage of a power meter to pace myself.

Lap 4: The terrain was similar to lap 6 when lap 6 was 18-19.7k, even so the readings are completely different (Lap 4 is about 2% steeper).

Lap 5: As on lap 2 the readings were just fine. As you see the terrain was only going uphill

Lap 7; I tried to use the brakes the least I could. I don´t understand why the color of the graph shows the contrary, and I never touch the brakes from 24.3 til the end of the ride

In the past I tried to fix these issues, and I even send my unit to Tom Gore for an exchange. Before doing that he thought the mount was not properly tighten, I can warranty you that it is indeed very tight. The new unit kept doing the same things I report on file. I also get the same results when I use my other bike with another mount (both are on the handlebars).
This is the way my Newton records my rides. I stop trying to correct it, but here I go again hoping for a solution from you. Please let me know if this is an issue that can be fixed. Or I have to accept that the unit does its best only going uphill.

[Velocomp]

Well, there is good news and bad news:

1) Good news is that your Newton is working

2) Good news: your wind sensor is well-calibrated

3) Bad news: your Newton's "slope offset" calibration is way out of whack; the Newton has to "correct" the setting by nearly -18% (it should be just a fraction of one percent)

When the Newton is this far away from correct settings, it's like listening to your music system where the volume is set to "one", so you turn your headphones up to "11" so you can hear anything...

Please do a new calibration ride (see Newton and Isaac instructions to get the correct settings) and post a ride after doing so.

[juancito27]

Hello:

Thank you very much for your help.

I look forward to reading your comments on the cal ride, and the short one files.

On the short ride lap1 is pretty much as lap3 from yesterdays. The readings look right to me.

Lap 2 has its issues since no power was showing on the little downhill at the start of the lap (about 3%), it took about 1.5k for the newton to catch up

Lap 3 was also fine

Lap 4 I don´t think I was producing too much power except for the flat section on 12k. This time the Newton catched up faster than on lap 2

I don´t understand why the grapah keeps showing that I was braking when I was not, please explain this to me. The first part of the descend looks fine.

[Velocomp]

Where are you located? The elevation is around 9500 feet. Can this be correct?

[juancito27]

Yes, it is correct. The maximum altitude on today´s ride was very close to 10,000 feet

https://www.strava.com/activities/435267251

[Velocomp]

Everything in your ride file looks normal. For the final descent, the slope of the descent is about -5%, but the Newton accelerometer is measuring as much as -30%. The difference, in the software, is being attributed to braking.

The accelerometer signal in the last descent is really "noisy", so it's possible that the Newton accelerometer is getting confused.

What kind of mount are you using with your Newton?

[juancito27]

I´m using a front mount.

Please take a look of today´s ride. The highest point was more than 10,000 feet.

Lap 5 was basically the same as lap1 from November 18th. But the numbers are completely different.

Lap 6 is the same as lap 2 from Novemver 18th. Again, the numbers are very different.

John, I really apprecite the time you put into this situation. I gather that something is wrong in fact very wrong. I´m not happy with the way my Newton performs. If the problem can be corrected, and if you are willing to try other things, I´m open to do so. When I was exchanging emails with Tom we tried different things with the mount like using sand paper to prevent sliding, tighting it really hard and nothing worked. I also tried using different profiles and no solution has been achieved.

I´m frustrating because since I started using both units (the one that was replaced by Tom Gore and this one) I haven´t gotten a single ride where I feel that the readings were right. Is the altitude playing a role? Why the accelerometer is confused? Every time I go to a descend the result is the same. I´m sorry to say that this is the only time when the Newton has been consistent.
Why when I go on a flat section the unit does not show the right amount of watts I´m producing?

How accurate are the readings when I go uphill?

I look forward to hearing from you.

[Velocomp]

I'm not sure what the issue is here.

Your ride from 11/18 shows average 107.3W for lap 1 (on the flats).

Your lap 5 today, for the same place, shows 108.6W watts.

I do not see that anything is very wrong.

No matter which file you think is correct, both on-the-flats efforts are small compared to the 183W you produced going up the hill. Wattage efforts uphill are generally higher, and easier to measure, than efforts on the flats. And the Newton is dead-on when reporting up-hill efforts.

I do note that your 11/20 file shows the same downhill vibration issue as your earlier file. We love the front mount, but it is not possible to achieve the same level of stiffness with the cantilevered beam of a front mount, as it is with a regular dual mount.

If measuring watts on high speed downhills is critical to you (and as a matter of cycling sport we would respectfully say that it is not) then you should use either the dual mount, or the solo mount, which is much stiffer than the front mount.

Or you can do what we do: ignore downhill numbers. On downhills we are trying to go fast by being in a tuck, and trying also not to go off the side of the road. What the power meter says is unimportant; our speed is determined by how aero our ride position is, and how well we are steering the bike. On downhills Nature is providing the power to go fast.

[juancito27]

Hi,

Downhill efforts are not as important as I made them sound, I just mentioned it as something that may indicate an issue.

I just used a power calculator and compare the results with the values from an uphill lap from Newton, and you are right, the precision of the Newton is remarkable

Could you please tell me which one would be the stiffest mount?

[juancito27]

Hi:

I made an adaptation on the front mount and I´m happy to report that the results look much better. I´m enclosing a file from todays and I´d like to point out some observations when compared with the ride from November 20th:

Lap 4 from todays is the same as lap 5 from the 20th. Lap 5 from today´s is the same as lap 6 from the 20th. Please note the difference in power being at least 15% higher in today´s reading, and close to 40% as maximum. Also, the little downhill part on 13k from todays shows the right color on the graph, the right grade and the right power production (I think).

On the ascend starting at 4k from todays in comparassion with the same chunck from the 20th the reading is about 7% higher, even so on the 20th I did it 53 seconds quicker.

The average grade on the descend shows 2.6% discrepancy with the ascend, and not 7.6% as it was before.

Please let me know if a different mount will improve even more the results, and which mount would you recommend, and I look forward to hearing from you

I´ll do one more thing with my current mount and if the results show improvement I´ll let you know.


Sincerely,
Juan