60 here.I'm 61, ditched the bar risers and went back to stock seating position.
No issues with my back what so ever.
I have back issues but the zx-14 position is like therapy.
My buddy is 78 and last year did the 1500 miles in 24 hours Iron Butt on his zx-14.
oh, and a 9.6 quarter mile.
Age in itself isnt a factor.
However, ride what you can & whatever makes you smile :grin2: