Calibration Check

[hydev]

Hi,

Can I please ask you to check my calibration - I think it's complete nonsense.

I have a Garmen Fenix 6x PRo, Garmin Speed Sensor and Power Pod V4

I did the calibration ride in accordance to the instructions, but I did not get the RED=STOP at 50W. My watch showed 50w, so I came to a stop, turned around and went back home.

Velocomp_03_09_2021_1813_1_km_CalRide.ibr

Calibration Ride

(18.79 KiB) Downloaded 313 times

I then went to computer and save the calibration ride. I then went and did a test 5km (2.5km out, 2.5km back).

Velocomp_03_09_2021_1909_5_km.ibr

5km Test

(53.87 KiB) Downloaded 268 times

And the bike profile:

Profile1_Hatchet2017.ibp

GravelProfile

(421 Bytes) Downloaded 220 times

However, it can't be correct as I looked down at my watch and it said I was doing 700W downhill (I wasn't peddling). Can you please help me understand what I am looking at?

Thanks

Mike

[Velocomp]

Yes, this ride file looks like complete nonsense...

It would appear your PP is not tightly attached to the mount. It is rotating, causing crazy slope problems.

Only the last few minutes of your ride is "normal".

Make sure your PP is firmly attached to the mount and cannot rotate. Then, do another ride of 10-15 minutes and post the ride file here.

[hydev]

Ok thanks - do you mean redo the calibration ride as well?

Mike

[Velocomp]

Ok thanks - do you mean redo the calibration ride as well?

Mike

No. Simply tighten down your PP on the mount so it cannot rotate, then do a short ride and post the results.

[hydev]

Hi - does this look better? It is very windy here today (25mph) but I would expect it to be fine with that. I tightened it down as hard as I could but worried about snapping bracket. I didn't see any daft values, so I'm hopeful.

Velocomp_03_10_2021_1806_5_km.ibr

(55.2 KiB) Downloaded 308 times

Thanks

Mike

[Velocomp]

You have some very big winds there, and some steep hills too!

I don't see evidence of rotation. I think you're OK but post a longer ride file (maybe on a less windy day...) when you can.

[lorduintah]

As far as tightening the PP into the holder - you mentioned that you thought you were getting it pretty tight, but did not want to break the plastic - a good train of thought.

Make it snug - if you think it is getting close to tight enough - hold onto the PP and see if with a small amount of force - not a lot - see if the PP rotates ------certainly not as much as you would use to open a fresh jar of jam or preserves - and if the PP does not move - you are there - otherwise I would do no more than a 1/8-th of a turn and try again - repeat.

Plastic is plastic - not any metal and the torque you use to tighten most stem clamps on your bike is about 5 nM - way, way more torque that you need to keep the PP from rotating.

Incidentally, I have found that the bracket is asymmetric - spacing, at least on mine, is not the same for all three fingers { |-|--| } --- not { |-|-| } -- crudely depicted here - so it may be necessary to rotate the disc on the out front holder 180 degrees by loosening the screw which will allow it to be turned. I saw one user in the form who broke a finger because he forced the PP into the holder.

[hydev]

Thanks for the top tips there. I will have another look at it tonight.

Cheers

Mike

[hydev]

Hi John - I have sent you an email to your technical support address.

Thanks

Mike

[hydev]

Hi - finally got the mount sorted so it won't move without stressing the plastic. Done a 23km ride so hopefully enough to make sure all is ok.

Thanks

Mike

Velocomp_03_15_2021_1200_1_Miles_CalRide.ibr

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Velocomp_03_15_2021_1753_14_Miles.ibr

(219.2 KiB) Downloaded 294 times

[Velocomp]

Hi - finally got the mount sorted so it won't move without stressing the plastic. Done a 23km ride so hopefully enough to make sure all is ok.

Thanks

Mike


Velocomp_03_15_2021_1200_1_Miles_CalRide.ibr
Velocomp_03_15_2021_1753_14_Miles.ibr

It looks like your PP isn't rotating--a good thing!

You ride some windy roads, and assuming this is true I think you are OK.

[hydev]

Hi - thanks for checking. I live in the Peak District, UK so hilly and it’s been very windy over the last week or so. Reckon it’s good

Mike