I'm sure it won't be able to handle wind noise well (it doesn't look big enough to have multiple microphones) so you'd have to stop the bicycle to make a good recording. Might as well grab the phone then.
Yes I know but I doubt it will capture much at all when there's significant wind noise, even enough to understand by ear without STT.
A friend of mine has her phone on her handlebars in a gps mount and she sends me voice messages through her bluetooth headset and those are hardly intelligible. A hand on the handlebar would be even further from the mouth.
And those are pretty good ones with multiple microphones.