That's the way moms are.
I was 53 yo when my mom passed away and she still worried about me, including my bike riding.
This from a woman who bought me my first bike as a child and years later my first Italian road bike (the Bottecchia).
She will never stop worrying about you.
Give her a big hug, tell her you love her very much and tell her that you love how much she cares for you.
Then tell her that you are doing this for your health.
Ride on and ride safely!
BTW, I miss my mom's "nagging!" Wish she was still around, over-worrying about me.
