Can't recall if it was Plane & Pilot or Private Pilot but,

I saw a blurb (with photo) about a bike rack for C172s that mouned
ABOVE the
cockpit just like on a car with straps that tied it down to the door
frames.

They claimed it had a minimal effect on W&B.

I remember seeing that in Private Pilot too. I wonder what kind of
cruise speed loss it causes?

It also seems like it'd be pretty difficult to get a bicycle on top of
a C172, let alone attached securely (and you'd sure want it to be
secure!).

Charles.
-N8385U