Friction values

[andrewlees]

I've had the Newton for about a year now. I recently bought a new stem (went from 6 degree to 17 degree angle) so I did a new cal ride and everything seemed fine. Then one day I started riding and the numbers weren't right. Stuff like 300W on a flat piece of road when the heart rate is at 120 and you're in the small ring.
I have done a few cal rides and I'm getting strange values. For instance, I typically have had friction values ~9, but I now have numbers <1.0. And now my tilt is at 0.5 from -0.7.
And even when I check the calibration of rides with these new profiles, the estimated friction was coming up <0! I'm a small guy, I use the same piece of road, same tire pressure, same everything.
I'm wondering if something could have happened to the Newton. If not, what could account for the drastic changes in friction and tilt. But even so, assuming the cal ride is done correctly, would everything sort itself out is something is out of wack internally?

[Velocomp]

Please post a ride file and we will figure out what is going on.

[andrewlees]

Ok, so what I've done here is posted the cal ride BEFORE weird stuff started happening, and then 2 after (to show consistency). All of these were done in perfect conditions (quiet roads, no wind changes, no drafting, out and back course, good cal wind done, tire pressure checked beforehand, Newton is stem mounted and secure).

[Velocomp]

Something has changed in your wind readings. Go into Setup, do a Cal Wind in a no-wind place, then do another Cal Ride. Please post the results.

[andrewlees]

John, here's the latest cal ride that was done with a no-wind cal ride. Values are quite similar.

[Velocomp]

This cal ride looks perfect. There are no peculiar variations in wind, as there was in the prior ride.

You should be good to go.

[andrewlees]

I have to admit, that the numbers do seem ok when riding. My only concern was the major change in the friction and tilt values between the first cal ride (April 13) and the recent cal ride (May 5). Tilt has gone from -0.9 to 0.5. The Newton position on the stem has not changed at all. Tires have not changed either.