Audio recording of e-bike ride

Here's a spectrogram of some of the audio of my ride on my e-bike today:

That wiggly line bothers me.  I can hear it in the recording, and it's definitely the electric motor making that sound.  The other thing is that I think either I've got the gain on the recorder too low (it's set to '20' for this data set), or having the recorder in my backpack is muffling (attenuating) the sound so much that the signal isn't very strong.  When I listen to the recording, it sounds like it's peaking, although the data doesn't indicate that.

Here's about the first four minutes of my outbound journey:

Also some accelerometer data with the recording device connected to the bike (as opposed to in my backback as it has been).  This is a short trip -- about 2.5 miles out, and 2.5 miles in.  You can clearly see the three times I hit the brakes near the beginning and end, and in the middle when I turned around.  Round trip is 789.5 seconds.

is this any better than what I already had?  Not sure yet.  I'm thinking that the device attached to the bike would have better S/N than the device flopping around in a backback.  But this is definitely different than what i've seen before.  The 6Hz line is still there, but there are other things at lower frequencies, and some interesting high freq stuff....

Also, Perseids:

USL012, and USL011.